Glossary of Terms

High-resolution 3D FLAIR acquired 4 hours after intravenous or 24 hours after intratympanic gadolinium. The current standard for in-vivo visualisation of endolymphatic hydrops in Ménière's disease.

In: Imaging

A stress-induced chaperone proposed as the target of the 68-kDa antibody described by Moscicki — historically the best-known AIED serological marker, but never standardised and now considered investigational.

In: Autoimmune Inner Ear Disease

The cranial nerve innervating the lateral rectus, which abducts the eye. Its nucleus in the pons also contains interneurons that drive the contralateral medial rectus via the MLF, making it the hub of horizontal conjugate gaze.

In: Neuro-Ophthalmology

A middle-ear muscle reflex to loud sound. PRESERVED in SSCD (the middle ear is normal) but ABSENT in otosclerosis — the key audiologic discriminator for an air–bone gap.

In: SSCD

A self-report scale of confidence in performing daily activities without losing balance — captures the psychological dimension of fall risk.

In: Vestibular Rehabilitation

A syndromic presentation of sudden continuous vertigo lasting more than 24 hours, with nausea, gait imbalance, and intolerance of head movement. The differential is broad — peripheral causes (vestibular neuritis) versus central causes (posterior circulation stroke) — and is resolved bedside by the HINTS examination.

In: Bedside Clinical Tests, Case-Based Discussion, Central Causes, Setting Up a Vertigo Clinic, Emergency Management, History Taking, Therapeutic Manoeuvres, Vestibular Neuritis & Labyrinthitis, Neuro-Ophthalmology, Pathophysiology

A rehabilitation mechanism that recalibrates the VOR using retinal slip as an error signal, restoring gaze stability during head movement.

In: Vestibular Rehabilitation

Branch of the basilar artery supplying the anterior-inferior cerebellum, lateral pontomedullary brainstem, and — via the labyrinthine artery — the inner ear. AICA infarction can mimic peripheral vestibular neuritis because the labyrinth is involved, but bedside hearing testing (HINTS-Plus) detects the additional cochlear infarction.

In: Central Causes, History Taking, Pathophysiology

Posterior-circulation stroke that may involve the labyrinthine artery, producing peripheral-pattern vHIT plus hearing loss. A 'pseudoneuritis' mimic of vestibular neuritis.

In: vHIT

Infarct in the anterior inferior cerebellar artery territory — vertigo + ipsilateral hearing loss + facial paresis. Common stroke that masquerades as labyrinthitis.

In: Emergency Management

Difference between air-conduction and bone-conduction thresholds at a given frequency. A gap ≥ 10 dB indicates a conductive component. Low-frequency air-bone gaps occur in otosclerosis but also in third-window pathologies such as SCDS (where the gap is pseudo-conductive).

In: Pathophysiology, SSCD

Chronic toxic ataxia from prolonged heavy alcohol use. Anterior-vermis-predominant atrophy producing gait ataxia with relatively preserved limb coordination. Originally described by Victor and Adams in 1959 as a distinct entity from Wernicke-Korsakoff syndrome. Modern data implicate concurrent nutritional deficiency and gluten sensitivity as contributors.

In: Pathophysiology

Drowsiness collapses VOR gain. The tester engages the subject in arithmetic, naming, or country-listing to keep arousal up. Without alerting, gain may falsely appear reduced.

In: Rotational Chair

Empirical observation that horizontal peripheral vestibular nystagmus increases in amplitude when the patient looks in the direction of the fast phase, and decreases when looking in the opposite direction. Used at the bedside as one feature suggesting a peripheral rather than central origin.

In: Bedside Clinical Tests, Emergency Management, Vestibular Neuritis & Labyrinthitis, Neuro-Ophthalmology, Pathophysiology, vHIT

Vestibular hair-cell damage from aminoglycoside antibiotics (notably gentamicin), one of the commonest identifiable causes of BVP; it is typically bilateral, may spare hearing, and can appear after apparently safe serum levels.

In: Bilateral Vestibulopathy

Potassium-channel blockers that enhance cerebellar Purkinje-cell activity. 4-aminopyridine can reduce downbeat nystagmus and episodic ataxia type 2, improving gaze stability and oscillopsia.

In: Neuro-Ophthalmology

The dilated end of each semicircular canal containing the crista ampullaris — the sensory epithelium with hair cells that detect angular acceleration. The cupula sits on the crista and is deflected by endolymph flow.

In: Pathophysiology, vHIT

Antineutrophil cytoplasmic antibodies — serological markers of vasculitides such as GPA; their detection supports a vasculitic cause of audiovestibular disease.

In: Autoimmune Inner Ear Disease

Standards defining the maximum permissible ambient noise levels for audiometric test rooms. Bone-conduction thresholds are invalid in untreated spaces.

In: Setting Up a Vertigo Clinic

Rare variant of BPPV (~3% of cases) from otoconia in the anterior semicircular canal, provoked by head extension; characteristically produces transient downbeating-torsional nystagmus on the Straight Head Hanging Test.

In: Bedside Clinical Tests

A saccade in the same direction as the head movement, generated by healthy subjects in the SHIMP paradigm to catch up to the head-fixed laser target.

In: vHIT

The cumulative effect of all anticholinergic medications a patient takes. A high burden raises the risk of confusion, delirium, falls and cognitive decline, especially in older adults.

In: Pharmacology

Ondansetron (preferred in the ED) or prochlorperazine for symptomatic relief of vomiting. Watch for QT prolongation in elderly and frail.

In: Emergency Management

A prothrombotic autoimmune disorder (anticardiolipin / anti-β2-glycoprotein-I antibodies) that can cause inner-ear microthrombosis and recurrent or sudden hearing loss and vertigo.

In: Autoimmune Inner Ear Disease

Nystagmus beating toward the upper ear (toward the ceiling) on supine roll testing. In lateral canal BPPV, apogeotropic nystagmus suggests cupulolithiasis or a variant. The affected ear is the side where the response is LESS intense (reverse of geotropic).

In: BPPV, Cervicogenic Dizziness, Therapeutic Manoeuvres, Pathophysiology

Quantitative map derived from DWI. Acute ischaemic tissue shows reduced ADC; T2 shine-through can produce a bright DWI signal without true restriction, so ADC is read alongside DWI to confirm acute infarction.

In: Imaging

A side-to-side audiometric difference suggesting a retro-cochlear lesion. The classical screening criterion is >15 dB asymmetry at 3 or more contiguous frequencies. In a dizzy patient, asymmetric hearing loss raises suspicion of vestibular schwannoma and warrants MRI with IAM protocol.

In: Cervicogenic Dizziness

Graphical record of hearing thresholds at each frequency, measured separately for each ear. Air-conduction (headphone) thresholds use ◯ for right and ✕ for left; bone-conduction (bone oscillator) thresholds use ⊏ and ⊐. The shape, symmetry, and air-bone gap are diagnostic.

In: Pathophysiology

Sound-attenuating enclosure meeting ANSI S3.1 / ISO 8253 ambient-noise limits. Non-negotiable for valid audiometry; one of the larger capital items.

In: Setting Up a Vertigo Clinic

Plan-Do-Study-Act loop applied to the clinic: pick a metric (e.g., same-visit diagnosis rate), measure, change one variable, re-measure. Quarterly cadence works for most vestibular clinics.

In: Setting Up a Vertigo Clinic

Technologies that overlay virtual elements onto the real world (AR) or blend the two interactively (MR), giving more ecologically valid, transferable balance training than fully virtual environments.

In: Emerging Technologies

Fully reversible neurological symptoms — most often visual (shimmering scotoma, fortification spectra) — that precede or accompany a migraine. Visual aura can itself satisfy criterion C.

In: Vestibular Migraine

A sensation of pressure or blockage in the affected ear, often a premonitory warning of an attack.

In: Ménière's Disease

An aberrant immune response against inner-ear antigens causing rapidly progressive, often bilateral sensorineural hearing loss with vestibular symptoms. Rare (<1% of SNHL) but important because it is steroid-responsive if caught early.

In: Autoimmune Inner Ear Disease

Abnormal perception of one's own voice as louder, hollow, or echoing in the affected ear — and in florid cases, perception of one's own bodily sounds (eyeballs moving, footsteps, heartbeat). A cardinal symptom of superior canal dehiscence and other third-window disorders.

In: Pathophysiology, SSCD

Bárány Society term for vestibular neuritis. A clinical syndrome of acute, prolonged unilateral vestibular nerve dysfunction without hearing loss.

In: vHIT

Acute continuous vertigo lasting more than 24 hours, with nausea, head-motion intolerance, and gait unsteadiness. Differential includes vestibular neuritis, labyrinthitis, posterior circulation stroke.

In: vHIT

International society for neurootology that publishes the consensus diagnostic criteria for most vestibular disorders, including BPPV (2015), Ménière's (2015 with AAO-HNS), vestibular migraine (2012 with IHS), SCDS (2021), vestibular neuritis (2022), and PPPD (2017).

In: Pathophysiology, Vestibular Migraine

Tissue injury from a pressure differential — here, diving, flying or a forceful Valsalva transmitting pressure to the inner-ear windows. The commonest clear precipitant of PLF.

In: Perilymphatic Fistula

The American Geriatrics Society list of potentially inappropriate medications in older adults. It flags first-generation antihistamines and benzodiazepines — both common vestibular suppressants.

In: Pharmacology

Brief positional vertigo caused by free-floating otoconia (canalithiasis) or otoconia adherent to a cupula (cupulolithiasis) in a semicircular canal. The most common cause of vertigo overall. Posterior canal BPPV is most common, but lateral canal BPPV exists and requires different treatment.

In: Bedside Clinical Tests, BPPV, Cervicogenic Dizziness, Setting Up a Vertigo Clinic, History Taking, Therapeutic Manoeuvres, Neuro-Ophthalmology, Understanding Symptoms

Brief, sudden spells of vertigo in children aged 2–7, with normal examination and full recovery between episodes. A migraine precursor that often evolves into vestibular migraine in adolescence — not to be confused with adult BPPV.

In: History Taking, Paediatric & Elderly

A 14-task performance scale of static and dynamic balance, predictive of falls and responsive to rehabilitation progress.

In: Vestibular Rehabilitation

A marker of CSF/perilymph used to confirm a leak; less specific for perilymph than CTP but more widely available in some settings.

In: Perilymphatic Fistula

A histamine analogue (weak H1 agonist, potent H3 antagonist) used as first-line maintenance prophylaxis in Ménière's disease; reduces vertigo frequency with an uncertain effect on hearing.

In: Ménière's Disease, Pharmacology

Reduced or absent function in both vestibular systems, causing oscillopsia and high fall risk. VRT relies on substitution and safety, not VOR recovery.

In: Vestibular Rehabilitation

Loss of vestibular function in both labyrinths — from ototoxicity, autoimmune disease, or CANVAS. At the bedside: bilaterally positive HIT, dramatically positive Romberg, oscillopsia, and gait worsened in the dark.

In: Bedside Clinical Tests, Bilateral Vestibulopathy, Neuro-Ophthalmology, Paediatric & Elderly, vHIT

Irrigation of each ear with warm and cool water or air to drive the horizontal canal at low (~0.003 Hz) frequency. The Bárány criterion for BVP is a reduced caloric response with the sum of the maximum slow-phase velocities below 6°/s per ear.

In: Bilateral Vestibulopathy

Warm and cool water (or air) irrigation of each external ear, with VNG-recorded nystagmus. The only test of low-frequency horizontal-canal function — irreplaceable in unilateral hypofunction work-up.

In: Setting Up a Vertigo Clinic

The barrier that keeps the inner ear immune-privileged by excluding circulating immune cells and large molecules. Its breakdown lets immune components reach inner-ear antigens and initiate AIED.

In: Autoimmune Inner Ear Disease, Pharmacology

Abnormally acute hearing of bone-conducted sound — patients may hear their own eye movements, footsteps or pulse. Reflected audiometrically as supranormal (better-than-0 dB) bone-conduction thresholds.

In: SSCD

Seated manoeuvre that aids lateralisation in horizontal-canal BPPV. Bowing forward and leaning back change the orientation of the canal and the direction of the elicited horizontal nystagmus identifies the affected side.

In: Bedside Clinical Tests

Rotational vertebrobasilar insufficiency from mechanical compression of one vertebral artery on cervical rotation, usually at the C1–C2 articulation. Provocation produces vertigo, nystagmus, diplopia, or drop attacks; confirmed by dynamic vertebral-artery imaging.

In: Bedside Clinical Tests

The most common cause of vertigo. Brief episodes of vertigo (seconds, sometimes up to a minute) triggered by specific head positions, caused by free-floating otoconia in a semicircular canal (canalithiasis) or rarely attached to the cupula (cupulolithiasis). Most commonly involves the posterior canal.

In: Pathophysiology, vHIT

Symptoms localising to the brainstem or posterior circulation: dizziness (with other features), diplopia, dysarthria, dysphagia, drop attacks, and perioral or limb numbness. Reproducible brainstem symptoms on sustained head rotation are the hallmark of RVAS and warrant urgent vascular workup.

In: Cervicogenic Dizziness

Low-cost SVV paradigm: the patient looks into a bucket with a vertical line drawn inside the rim, eliminating external visual cues. The examiner rotates the bucket from a tilted starting position until the patient calls the line vertical. Validated against laboratory SVV with ~1° agreement.

In: Subjective Visual Vertical

Document that pairs the clinical need (catchment demand, referrer pain points) with the financial envelope (capital + 12-month operating cost, payer mix, expected volumes). The artefact that wins administrative approval.

In: Setting Up a Vertigo Clinic

The atlantoaxial joint, between the first (atlas) and second (axis) cervical vertebrae. Approximately 50% of cervical rotation occurs at C1–C2, and the densest proprioceptive afference in the cervical spine surrounds this segment. Dysfunction here disproportionately disturbs the head-position signal.

In: Cervicogenic Dizziness

Bedside or laboratory test of horizontal semicircular canal function by irrigating the external auditory canal with warm or cool air/water, which induces an endolymph current and nystagmus. Asymmetric responses (canal paresis) localise vestibular hypofunction; absent responses on one side suggest superior division neuritis or a profound peripheral lesion.

In: Cervicogenic Dizziness, Pathophysiology

Low-frequency vestibular test using warm/cool water or air irrigation of the external auditory canal. Stimulates the lateral canal at ≈ 0.003 Hz, complementary to high-frequency vHIT.

In: vHIT

A reduced caloric response on the affected side — evidence of a horizontal-canal/superior-division deficit. The classic confirmatory test in superior neuritis.

In: Vestibular Neuritis & Labyrinthitis

Reduced caloric response with preserved high-frequency vHIT gain. Highly specific for Meniere disease (≈ 84% specificity).

In: vHIT

Iatrogenic migration of otoconia from one semicircular canal into another during a repositioning manoeuvre — most often posterior-to-horizontal — producing a new pattern of positional nystagmus.

In: Therapeutic Manoeuvres

Occluding a semicircular-canal lumen to stop pathological endolymph flow — used for SSCD and for intractable posterior-canal BPPV; generally hearing-sparing and longer-lasting than resurfacing.

In: Surgical Management

Surgical occlusion (plugging) or recovering (resurfacing/capping) of the dehiscence — via a middle-cranial-fossa or transmastoid approach — to close the third window in disabling disease.

In: SSCD

Therapeutic head-movement sequences (e.g. the Epley manoeuvre) that relocate displaced otoconia from a semicircular canal back to the utricle in BPPV.

In: Understanding Symptoms

A sequence of head and trunk positions that uses gravity to roll dislodged otoconia out of a semicircular canal back into the utricle, where they no longer provoke vertigo.

In: Therapeutic Manoeuvres

The pathological state in which free-floating otoconia move within the lumen of a semicircular canal under gravity, producing brief positional vertigo (BPPV). Distinct from cupulolithiasis, where otoconia adhere to the cupula. Canalithiasis produces fatigable, latent nystagmus; cupulolithiasis is non-fatiguing.

In: BPPV, Cervicogenic Dizziness, Therapeutic Manoeuvres, Pathophysiology

Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome — a slowly progressive disorder combining bilateral vestibular failure with sensory neuropathy and cerebellar signs, a recognised cause of chronic oscillopsia.

In: Bilateral Vestibulopathy, Neuro-Ophthalmology

One-off purchases that create the clinic's fixed infrastructure: room build-out, audiometric booth, VNG/vHIT/VEMP systems. Amortised over 5–7 years in most budgeting frameworks.

In: Setting Up a Vertigo Clinic

Characteristic dip in bone-conduction thresholds (typically 5–15 dB at 2 kHz) seen in otosclerosis. The notch is not a true sensorineural loss — it reflects the impact of stapedial fixation on inner-ear mechanics. Helpful in distinguishing otosclerosis from SCDS, where bone conduction at 2 kHz is normal or supranormal.

In: Pathophysiology

Estimate of how many patients a service can realistically draw from its geography, given population, demographics and competing services. Drives the choice between solo and multidisciplinary models.

In: Setting Up a Vertigo Clinic

A relay nucleus in the upper cervical cord (C1–C3) that receives proprioceptive afferents from the deep neck muscles and joints and projects to the vestibular nuclei, where neck input integrates with labyrinthine input. The functional gateway through which cervical proprioception reaches the central balance pathways.

In: Cervicogenic Dizziness

The neuroplastic recalibration by which the brain adapts to unilateral vestibular loss after ablative surgery, restoring balance. It depends on a healthy opposite labyrinth and is accelerated by vestibular rehabilitation.

In: Emerging Technologies, Vestibular Neuritis & Labyrinthitis, Rotational Chair, Surgical Management

HINTS pattern indicating a central rather than peripheral cause of acute vestibular syndrome: any one of normal head impulse, direction-changing nystagmus, or skew deviation. Properly performed, has higher sensitivity for stroke than early MRI within 24 hours of symptom onset.

In: Pathophysiology

Positional nystagmus of central origin: immediate onset with no latency, non-fatiguing, persistent, often direction-changing or purely vertical, and unresponsive to canalith repositioning — distinguishing it from BPPV.

In: Bedside Clinical Tests, Neuro-Ophthalmology

Positional vertigo arising from cerebellar or brainstem pathology. Suggested by non-fatiguing nystagmus, absent latency, pure downbeat or direction-changing patterns, and accompanying neurological signs.

In: BPPV

An adaptive process by which the brain shifts its sensory weighting when one input becomes unreliable. In chronic cervicogenic patients, prolonged altered cervical input leads to over-reliance on vision — producing the supermarket, scrolling, and crowd-environment symptoms of Route 4. Requires retraining rather than further manual therapy.

In: Cervicogenic Dizziness

Heightened responsiveness of central nociceptive and vestibular neurons, proposed to link the migraine and vestibular networks and produce motion sensitivity between attacks.

In: Vestibular Migraine

Vertigo arising from disease of the central vestibular structures — vestibular nuclei, brainstem, cerebellum, thalamus or cortex — rather than the labyrinth or vestibular nerve. Typically non-fatiguing, often with other neurological signs, and frequently not suppressed by visual fixation.

In: Bedside Clinical Tests, Central Causes, History Taking, Neuro-Ophthalmology, Understanding Symptoms

Cluster of executive, visuospatial, linguistic, and affective disturbances first described by Schmahmann and Sherman in 1998 in patients with cerebellar lesions. Frequently the most disabling aspect of cerebellar pathology and frequently missed when attention focuses on motor signs. Screened with the CCAS scale.

In: Pathophysiology

A vestibulocerebellar region that calibrates VOR gain, enables fixation suppression and smooth pursuit, and holds eccentric gaze. Floccular dysfunction produces gaze-evoked and downbeat nystagmus and saccadic pursuit.

In: Neuro-Ophthalmology

An ischaemic or haemorrhagic insult to the cerebellum, often presenting with vertigo, imbalance, and nystagmus. It is frequently missed on early imaging, which is why bedside signs and a careful history matter so much.

In: History Taking

CSF cistern between the pons, cerebellum and petrous bone. Site of vestibular schwannoma, meningioma, epidermoid and the classic 'ice-cream-cone' tumour configuration extending out of the IAC.

In: Imaging

The hindbrain structure coordinating movement, gaze-holding, and vestibular-reflex modulation. The flocculus/paraflocculus and nodulus/uvula are central to pursuit, VOR calibration, and velocity storage; their lesions cause gaze-evoked and downbeat nystagmus.

In: Neuro-Ophthalmology, Rotational Chair

The phylogenetically newest cerebellar zone — the lateral hemispheres — that handles motor planning and contributes to cognitive and affective processing. Lesions produce ipsilateral limb dysmetria, dysarthria, and the cerebellar cognitive-affective syndrome (CCAS).

In: Pathophysiology

A bedside test in which the patient's head is held still while their trunk is rotated underneath, stimulating cervical receptors without moving the vestibular system. Reproduction of dizziness implicates the cervical receptors. The defining feature is that the vestibular system stays in the same gravitational position throughout.

In: Cervicogenic Dizziness

A complementary reflex to the VOR that uses neck-derived (rather than labyrinthine) input to stabilise gaze during head-on-trunk and trunk-on-head movements. Normally subordinate to the VOR but can be up-regulated in vestibular hypofunction.

In: Cervicogenic Dizziness

A clinical entity in which dizziness or unsteadiness arises from disturbed cervical afferent input. A diagnosis of exclusion: peripheral vestibular and central causes must be excluded first. Four mechanism routes are recognised: proprioceptive mismatch, vestibulo-sympathetic loop, RVAS, and central reweighting / chronic.

In: Bedside Clinical Tests, Cervicogenic Dizziness, Understanding Symptoms

Calcitonin gene-related peptide — a neuropeptide central to migraine pathophysiology and the target of modern monoclonal-antibody and gepant therapies.

In: Vestibular Migraine

A medullary centre that detects emetic stimuli and drives nausea and vomiting. Its H1, M1 and D2 receptors are the targets of antiemetic vestibular suppressants.

In: Pharmacology

Herniation of the cerebellar tonsils through the foramen magnum, crowding the cervicomedullary junction. A classic structural cause of downbeat nystagmus and central vertigo.

In: Neuro-Ophthalmology

A destructive keratinising squamous epithelial growth in the middle ear, capable of eroding bone and producing a labyrinthine fistula. Vertigo with pressure-induced provocation in chronic otitis media should raise this suspicion.

In: Bedside Clinical Tests

Staab and Ruckenstein's syndrome of persistent non-vertiginous dizziness with hypersensitivity to motion and visual stimuli — the other main precursor merged into PPPD.

In: PPPD

Persistent dizziness or imbalance over months — PPPD, bilateral vestibulopathy, presbyvestibulopathy or MdDS — where the pattern of provocation or relief is the diagnostic key.

In: Case-Based Discussion

Standardised six-condition test (firm/foam × eyes open/closed/visual conflict) that probes the relative reliance on visual, proprioceptive, and vestibular inputs to balance.

In: Bedside Clinical Tests

A first, monophasic episode of CNS demyelination — which may present as isolated vertigo or a brainstem syndrome — not yet meeting full MS criteria. Requires follow-up and repeat imaging to establish or exclude MS.

In: Central Causes

A narrow channel connecting the perilymph of the scala tympani with the cerebrospinal fluid — the conduit for the explosive route of window rupture.

In: Perilymphatic Fistula

Auditory rehabilitation that can restore hearing after schwannoma surgery or in NF2 when the cochlear nerve is anatomically and functionally intact — not a treatment for vertigo itself.

In: Autoimmune Inner Ear Disease, Surgical Management

A major non-collagenous extracellular-matrix protein of the cochlea and vestibule; anti-cochlin antibodies have been reported in some patients with immune-mediated hearing loss.

In: Autoimmune Inner Ear Disease

A protein specific to perilymph; its detection in a middle-ear lavage sample is a specific biochemical confirmation of a perilymphatic fistula.

In: Perilymphatic Fistula

An autoimmune vasculitis combining interstitial keratitis with audiovestibular dysfunction (SNHL, vertigo, tinnitus), often bilateral and progressive; may include large-vessel vasculitis such as aortitis.

In: Autoimmune Inner Ear Disease

Structured psychological therapy effective for PPPD, anxiety, and panic-related dizziness. Combined with vestibular rehabilitation, it reduces visual dependence and motion provocation.

In: Bedside Clinical Tests, PPPD, Understanding Symptoms, Vestibular Rehabilitation

The shared bony channel where the posterior and superior (anterior) semicircular canals join before entering the vestibule. Repositioning manoeuvres aim to carry debris through it back into the utricle.

In: Therapeutic Manoeuvres

Anxiety and depression are common in PPPD and amplify symptoms, but they are neither necessary for the diagnosis nor its sole cause — PPPD is a disorder of postural-perceptual function in its own right.

In: PPPD

A cascade that, once the blood–labyrinth barrier is breached, forms the membrane-attack complex (C5b-9) and directly lyses cochlear and vestibular cells.

In: Autoimmune Inner Ear Disease

Force-platform testing that quantifies postural sway under varied sensory conditions; its Sensory Organization Test isolates vestibular, visual and proprioceptive contributions.

In: Setting Up a Vertigo Clinic, Vestibular Rehabilitation

Hearing loss caused by impaired sound transmission through the outer or middle ear, producing an air-bone gap on audiometry with normal bone conduction. Causes include cerumen impaction, tympanic membrane perforation, ossicular discontinuity, otosclerosis, and effusion. SCDS produces a pseudo-conductive pattern with SUPRANORMAL bone conduction.

In: Pathophysiology

A slowly propagating wave of neuronal and glial depolarisation followed by suppression, thought to underlie migraine aura and to activate the trigeminovascular system.

In: Vestibular Migraine

Methylprednisolone taper for vestibular neuritis hastens caloric recovery but has modest effect on patient-reported outcome. Cochrane evidence remains contested.

In: Emergency Management

A corrective saccade that occurs during the head impulse, typically with latency 80–200 ms. Hidden to bedside examination; detectable only with vHIT. A marker of central compensation.

In: vHIT

Sensory epithelium within each semicircular canal ampulla, containing hair cells with stereocilia that project into the gelatinous cupula. Detects angular acceleration via cupular deflection.

In: Pathophysiology

Iodinated-contrast volumetric CT of intra- and extracranial vessels. High spatial resolution makes it the modality of choice in acute settings for basilar occlusion, vertebral dissection (intimal flap, mural haematoma) and posterior-circulation stenosis.

In: Emergency Management, Imaging

Gelatinous mass sitting on the crista ampullaris of each semicircular canal. Has the same specific gravity as endolymph, so it deflects with endolymph flow during angular head movement but is not affected by gravity in the resting state. Cupulolithiasis (otoconia stuck to the cupula) makes it gravity-sensitive, producing persistent positional symptoms.

In: Pathophysiology, Rotational Chair, vHIT

Mechanism of BPPV in which otoconia adhere to the cupula rather than floating in the canal lumen, making the cupula gravity-sensitive. Produces longer-duration positional nystagmus (>60 seconds) than canalithiasis, and apogeotropic direction in the horizontal-canal variant.

In: BPPV, Cervicogenic Dizziness, Therapeutic Manoeuvres, Pathophysiology

Pain or discomfort from a normally non-painful stimulus (e.g. brushing hair), reflecting central sensitisation during a migraine attack.

In: Vestibular Migraine

Vestibular-evoked myogenic potential recorded from the sternocleidomastoid muscle in response to loud acoustic stimulation. Measures the saccular–inferior vestibular nerve–vestibulospinal pathway. Absent in selective inferior-division neuritis; enhanced (lowered threshold, increased amplitude) in SCDS.

In: Pathophysiology

Motion-sickness-like nausea, dizziness and disorientation from the sensory conflict of VR use — the main tolerability barrier, affecting a substantial fraction of users.

In: Emerging Technologies

The historical eponym for the symptom complex of bilateral vestibular loss — oscillopsia and imbalance — described in patients after bilateral surgical vestibular nerve section.

In: Bilateral Vestibulopathy

The longus colli and longus capitis muscles that lie deep along the anterior cervical spine. They are crucial postural stabilisers of the head-on-neck, and their dysfunction is a recurring finding in cervicogenic dizziness. Deep cervical flexor strengthening is a core component of Route 1 management.

In: Cervicogenic Dizziness

Loss of the myelin sheath around central axons, slowing or blocking conduction. The pathological hallmark of multiple sclerosis; plaques in vestibular pathways produce central vertigo.

In: Central Causes

Advanced diffusion technique that quantifies the directionality of water diffusion along white-matter tracts. Used in research to probe vestibulospinal and medial longitudinal fasciculus integrity in multiple sclerosis and chronic vestibulopathy.

In: Imaging

MRI sequence sensitive to the random motion of water molecules. Acute cytotoxic oedema (early ischaemia) restricts diffusion and appears bright on DWI with corresponding dark ADC, allowing detection of cerebellar and brainstem infarcts within minutes of onset.

In: Central Causes, Imaging

MRI sequence that detects acute infarction in minutes. False-negative rate for small posterior-fossa strokes is 12–20% in the first 24–48 hours.

In: Emergency Management

Perceived double image from misalignment of the visual axes. In vertigo it is usually binocular and central — from skew deviation, INO, ocular tilt reaction, or a cranial-nerve palsy.

In: History Taking, Neuro-Ophthalmology

Nystagmus whose fast phase reverses with the direction of gaze. A central sign; peripheral nystagmus is unidirectional and obeys Alexander's law.

In: Central Causes

Nystagmus that changes direction depending on eye position — e.g. left-beating on left gaze and right-beating on right gaze. A central sign in the HINTS examination, suggesting cerebellar or brainstem pathology rather than peripheral vestibular hypofunction.

In: Bedside Clinical Tests, Neuro-Ophthalmology, Pathophysiology

A sense of unsteadiness or imbalance without the illusion of spinning. It usually reflects cerebellar disease, sensory ataxia, or multisensory decline rather than an acute labyrinthine lesion.

In: History Taking, Understanding Symptoms

Admit when: any central HINTS feature, suspicion of stroke or TIA, posterior-fossa imaging changes, refractory vomiting, persistent gait instability, Wernicke concern, isolated SSNHL with vertigo.

In: Emergency Management

Safe-to-discharge: clear peripheral diagnosis, hydrated and able to mobilise, accompanied home, written warning signs, follow-up booked.

In: Emergency Management

The two pillars of MS diagnosis: lesions in ≥2 characteristic CNS sites (space) and lesions arising at different times (time), shown clinically, on serial MRI, or — for time — by simultaneous enhancing and non-enhancing lesions or CSF oligoclonal bands.

In: Central Causes

The diagnostic test for posterior canal BPPV. The patient is brought from upright to supine with the head turned 45° toward the tested side and extended 20° below horizontal. Positive when a characteristic upbeating-torsional nystagmus is provoked after a brief latency, with associated vertigo. Always performed BEFORE any cervical provocation in the workup of dizziness with neck pain.

In: Bedside Clinical Tests, Cervicogenic Dizziness, Emergency Management, Pathophysiology

The gold-standard positional test for posterior-canal BPPV: from sitting, the head is turned 45° and the patient laid back into head-hanging, provoking a torsional-upbeat nystagmus when positive.

In: BPPV, Therapeutic Manoeuvres, Understanding Symptoms

A 25-item patient-reported outcome quantifying the impact of dizziness across physical, emotional, and functional subscales (Jacobson & Newman 1990). Total scores 0–100; bands: 0–30 mild, 31–60 moderate, 61–100 severe. Minimum clinically important difference ≈ 18 points. Tracks change with treatment.

In: Cervicogenic Dizziness, Setting Up a Vertigo Clinic, Surgical Management, Vestibular Rehabilitation

Vertical nystagmus with the fast phase beating downwards, typically maximal on lateral and downward gaze. Pathognomonic of central pathology — most often localising to the cervicomedullary junction or the vestibulocerebellum (Chiari malformation, demyelination, drug toxicity).

In: Bedside Clinical Tests, Central Causes, Neuro-Ophthalmology, Pathophysiology

Doppler interrogation of the vertebral arteries in neutral and provocative head positions. The screening investigation for RVAS — loss of end-diastolic velocity in V3 on sustained rotation, with the contralateral side preserved, is the early haemodynamic signature. Confirmatory imaging is dynamic CTA or catheter angiography.

In: Cervicogenic Dizziness

Visual acuity measured during head movement. A drop of more than two Snellen lines compared with the static chart indicates an inadequate VOR — a bedside test for oscillopsia and bilateral vestibular loss.

In: Bilateral Vestibulopathy, Neuro-Ophthalmology, Vestibular Rehabilitation

Slurred or slowed speech from impaired motor control of articulation. In a vertiginous patient it points to brainstem involvement.

In: History Taking

A test recording cochlear potentials; an elevated summating-potential to action-potential (SP/AP) ratio supports hydrops, though sensitivity is limited.

In: Setting Up a Vertigo Clinic, Ménière's Disease

High-potassium fluid filling the membranous labyrinth. Movement of endolymph during head motion deflects the cupula or otoconial membrane, opening hair-cell mechanotransduction channels. Endolymphatic hydrops — abnormal expansion of endolymphatic spaces — is the underlying mechanism of Ménière's disease.

In: Ménière's Disease, Pathophysiology

Abnormal dilatation of endolymphatic spaces, accepted as the histopathological substrate of Ménière's disease. Hydrops can be confirmed in vivo on delayed gadolinium MRI of the inner ear. Hydrops is necessary but possibly not sufficient — asymptomatic hydrops has been documented histologically.

In: History Taking, Imaging, Ménière's Disease, Pathophysiology, Pharmacology

The blind-ended structure that resorbs endolymph and regulates its volume; a target of decompression surgery.

In: Ménière's Disease

Decompression or shunting of the endolymphatic sac for refractory Ménière's disease — the least destructive option, hearing-sparing, with 60–80% vertigo control but debated efficacy.

In: Surgical Management

First-line treatment for posterior canal BPPV. Five-step sequence that moves otoconia out of the posterior canal and back into the utricle. Approximately 80% single-session success. AAO-HNS 2017 makes a strong recommendation AGAINST post-procedure postural restrictions.

In: Bedside Clinical Tests, Cervicogenic Dizziness, Setting Up a Vertigo Clinic, Emergency Management, Pathophysiology

Annual maintenance + calibration agreement bundled with the purchase of VNG/vHIT/VEMP systems. Typically 8–12% of capital cost per year; cheaper than ad-hoc repair.

In: Setting Up a Vertigo Clinic

Surgical elevation of the eardrum to inspect the round and oval windows for a leak and to repair it — the historical reference standard, though observer-dependent.

In: Perilymphatic Fistula

Window rupture from within — a surge of CSF pressure transmitted via the cochlear aqueduct to the perilymph blows the window membrane outward (Goodhill).

In: Perilymphatic Fistula

Movement side effects — acute dystonia, parkinsonism, akathisia — from dopamine-antagonist antiemetics such as prochlorperazine and metoclopramide, especially with prolonged use or in children.

In: Pharmacology

A leading cause of injury and loss of independence in older adults. Vestibular hypofunction is a modifiable contributor; multifactorial assessment and exercise-based prevention reduce fall risk.

In: Paediatric & Elderly

Diminution of the vertigo and nystagmus on repeated positional testing, as otoconia disperse or responses habituate. Characteristic of peripheral BPPV and absent in central positional nystagmus.

In: BPPV

Heavily T2-weighted thin-slice MRI sequences that produce high CSF–nerve contrast. The gold-standard read for cranial nerves in the internal auditory canal, the membranous labyrinth and the cerebellopontine angle cistern.

In: Imaging

Application of pressure to the external auditory canal (positive or negative, via pneumatic otoscope or tragal pressure) to test for an abnormal communication between the middle ear and the inner ear. A positive test — vertigo and/or eye movement — suggests perilymph fistula, SCDS, or labyrinthine fistula from cholesteatoma.

In: Pathophysiology, Perilymphatic Fistula

T2-weighted MRI sequence that nulls the cerebrospinal fluid signal, sharpening the visibility of periventricular white matter plaques (multiple sclerosis), small infarcts adjacent to CSF spaces and posterior fossa pathology.

In: Imaging

A calcium-channel blocker that stabilises vestibular neurons; an RCT-supported prophylactic for vestibular migraine. Side effects include weight gain, sedation and parkinsonism.

In: Pharmacology

Autosomal-recessive cerebellar ataxia caused by GAA-repeat expansion in the frataxin gene. Onset first to second decade. Phenotype: progressive ataxia with areflexia, Babinski sign, cardiomyopathy, and diabetes. The Harding 1981 criteria define the classical phenotype.

In: Pathophysiology

Patient marches in place 50–100 steps with eyes closed and arms outstretched. Rotational drift > 30° toward the hypofunctioning side suggests unilateral vestibular loss. Sensitive but non-specific.

In: Bedside Clinical Tests

A condition in which symptoms arise from altered functioning of the nervous system rather than from structural damage — genuine and disabling, and diagnosed on positive features, not merely by exclusion.

In: PPPD

Dizziness without an identifiable structural lesion, including persistent postural-perceptual dizziness (PPPD). Often associated with anxiety, hypervigilance, and sensory mismatch, and real and disabling for the patient.

In: History Taking

A performance measure of gait under challenge (head turns, obstacles, narrow base), assessing dynamic stability and fall risk.

In: Vestibular Rehabilitation

MRI of the blood-oxygen-level-dependent (BOLD) signal during sensory, motor or cognitive tasks. In vestibular disease it maps the cortical vestibular network and its disruption in PPPD and vestibular migraine.

In: Imaging

The main inhibitory neurotransmitter receptor in the CNS. Benzodiazepines potentiate it, hyperpolarising neurons and damping excessive vestibular-nucleus firing.

In: Pharmacology

Paramagnetic intravenous contrast that shortens T1, brightening sites of blood–brain or blood–labyrinth barrier breakdown — vestibular schwannomas, active demyelinating plaques, suppurative labyrinthitis.

In: Imaging

Five-tier system: normal (≥ 0.80), mild (0.70–0.79), moderate (0.40–0.69), severe (0.20–0.39), profound (< 0.20).

In: vHIT

Small transmastoid currents that bias vestibular afferents; delivered as low-level noise, stochastic resonance can paradoxically improve balance in bilateral vestibulopathy.

In: Emerging Technologies

Small transcutaneous current applied behind the ears to activate the vestibular nerve — used as a stimulus in fMRI experiments to probe central vestibular processing in health and disease.

In: Imaging

Nystagmus that appears or worsens on eccentric gaze, with the fast phase beating in the direction of gaze. Common in cerebellar or brainstem pathology (multiple sclerosis, drugs like phenytoin), or with neuromuscular causes of gaze-holding failure.

In: Bedside Clinical Tests, Neuro-Ophthalmology, Pathophysiology

Vestibular-rehabilitation exercises (e.g. ×1 and ×2 viewing) that drive adaptation and substitution to reduce oscillopsia and improve gaze stability when VOR function is reduced.

In: Bilateral Vestibulopathy, Vestibular Rehabilitation

Vector-delivered genes — for example the transcription factor Atoh1 — intended to regenerate vestibular hair cells. Promising in animal models; not yet in vestibular clinical use.

In: Emerging Technologies

Positional nystagmus that beats TOWARDS the ground (towards the down-side ear during the supine roll test). The geotropic pattern is characteristic of horizontal canal canalithiasis; the affected side is the side where the nystagmus is more intense.

In: BPPV, Cervicogenic Dizziness, Therapeutic Manoeuvres, Pathophysiology

Immune-mediated cerebellar ataxia in patients with gluten sensitivity, mediated by anti-transglutaminase-6 (anti-TG6) and anti-gliadin antibodies. May respond to gluten-free diet in some cases. Often without overt gastrointestinal disease.

In: Pathophysiology

An ANCA-associated granulomatous vasculitis of the airways and kidneys that can cause otitis media, SNHL and progressive vestibular symptoms, with bony destruction if untreated.

In: Autoimmune Inner Ear Disease

The neural sense of gravity. Combines otolith afferents, somatosensory cues (truncal graviceptors), and visual cues; integrated in the brainstem, cerebellum, thalamus, and parieto-insular vestibular cortex.

In: Subjective Visual Vertical

Alternative treatment for HC-BPPV, with separate variants for canalithiasis (geotropic) and cupulolithiasis (apogeotropic).

In: Emergency Management

A histamine receptor in the vestibular nuclei and CTZ. Antihistamines block it to reduce vestibular signalling and nausea; betahistine, by contrast, is a weak H1 agonist.

In: Pharmacology

A presynaptic autoreceptor regulating histamine release. Betahistine antagonises it, increasing inner-ear blood flow and endolymph resorption in Ménière's disease.

In: Pharmacology

Reduction of an abnormal symptomatic response through controlled, repeated exposure to a provocative movement or visual stimulus.

In: Vestibular Rehabilitation

A treatment approach using graded, repeated provocation of dizziness-triggering positions to desensitise the central response over time. Useful for some forms of motion-provoked dizziness and as a second-line BPPV strategy. CONTRAINDICATED in RVAS, where habituation may worsen the underlying vascular event.

In: Cervicogenic Dizziness

Mechanosensory cell in the inner ear that converts mechanical movement (cochlear basilar membrane displacement, or vestibular cupular/otoconial membrane deflection) into a receptor potential. Vestibular hair cells have a single kinocilium and a graded array of stereocilia; deflection toward the kinocilium depolarises the cell.

In: Pathophysiology, Rotational Chair

Bedside test of the angular vestibulo-ocular reflex (VOR). With the patient fixating a target, the examiner makes a small, rapid, unpredictable head turn. A normal VOR keeps the eyes locked on the target; a hypofunctioning vestibular nerve produces a corrective catch-up saccade — the diagnostic positive sign of peripheral vestibular loss.

In: Bedside Clinical Tests, Central Causes, Emergency Management, Vestibular Neuritis & Labyrinthitis, Neuro-Ophthalmology, Pathophysiology, Understanding Symptoms, Vestibular Rehabilitation

Pressure-induced vertigo or eye movement — provoked by tragal pressure, pneumatic otoscopy, or Valsalva. A feature of third-window disorders (SCDS), perilymph fistula, and labyrinthine fistula from cholesteatoma. Hennebert in the absence of middle-ear disease is highly suggestive of SCDS.

In: Bedside Clinical Tests, Pathophysiology, Perilymphatic Fistula, SSCD

Vertigo and nystagmus provoked by pressure changes in the external auditory canal (e.g., pneumatic otoscopy). Classically seen with perilymph fistula, superior canal dehiscence, or labyrinthine fistula in chronic otitis media.

In: Bedside Clinical Tests, Imaging

Thin-section (≤0.6 mm) CT of the temporal bone optimised for the otic capsule, ossicular chain and skull base. The preferred modality for SSCD, otosclerosis, temporal bone fracture, labyrinthitis ossificans and bony involvement of cholesteatoma.

In: Imaging

A stiffened, over-cautious mode of standing and walking — tightened co-contraction and reliance on ankle strategy — adopted after a frightening vestibular event and maladaptively retained in PPPD.

In: PPPD

The conventional vHIT protocol. Patient fixates an earth-fixed target while head impulses are delivered. Measures the VOR's capacity to compensate for head motion.

In: vHIT

Three-step bedside examination for acute vestibular syndrome. Properly performed within 24 hours of symptom onset, HINTS has 100% sensitivity and 96% specificity for central cause (Kattah 2009) — outperforming early MRI. Components: head impulse test, nystagmus character, and test of skew. Any one central feature suggests stroke.

In: Case-Based Discussion, Central Causes, Imaging, Vestibular Neuritis & Labyrinthitis, Pathophysiology, vHIT

Three-step bedside battery for AVS — Head Impulse, Nystagmus pattern, Test of Skew. A central pattern (normal HIT, direction-changing nystagmus, or vertical skew) is more sensitive than early DWI-MRI for posterior-circulation stroke.

In: Setting Up a Vertigo Clinic, Emergency Management

A three-step bedside battery used to distinguish peripheral from central causes of acute vestibular syndrome. Comprises Head Impulse Test, Nystagmus characterisation, and Test of Skew. A 'peripheral' HINTS pattern (abnormal head impulse, unidirectional horizontal nystagmus, no skew) is more sensitive than early MRI for stroke exclusion in the acutely dizzy patient.

In: Bedside Clinical Tests, Cervicogenic Dizziness, History Taking, Therapeutic Manoeuvres, Neuro-Ophthalmology

HINTS plus bedside hearing testing. Adds sensitivity for AICA infarction, which can produce an abnormal head impulse (from labyrinthine artery involvement) and look peripheral on standard HINTS — but adds acute unilateral hearing loss as a discriminator.

In: History Taking, Pathophysiology, vHIT

The structured set of VRT exercises a patient performs independently between clinic visits — typically 2–3 times daily for 10–20 minutes.

In: Vestibular Rehabilitation

Variant of BPPV affecting the horizontal (lateral) semicircular canal. Diagnosed on the supine roll test (not Dix-Hallpike). Produces horizontal positional nystagmus — geotropic if canalithiasis, apogeotropic if cupulolithiasis. Treated with the Lempert (barbecue) roll or Gufoni manoeuvre.

In: Bedside Clinical Tests, Emergency Management, Pathophysiology

Simultaneous acquisition of metabolic (PET) and anatomical/functional (MRI) information. Promising for chronic dizziness syndromes with normal structural imaging — correlates PIVC activity with structural connectivity in one session.

In: Imaging

Excessive sensory self-monitoring, common in anxiety-related conditions and PPPD, that helps perpetuate symptoms.

In: Understanding Symptoms

The International Classification of Headache Disorders (3rd edition) — the reference standard for diagnosing migraine, which criterion B of vestibular migraine relies on.

In: Vestibular Migraine

Features that should trigger imaging in a vertigo presentation: focal neurology, new severe headache, vertical or direction-changing nystagmus, acute hearing loss with vertigo, vascular risk factors with sudden symptoms, failure of conservative management.

In: Imaging

The degree to which a VR system surrounds the user — from a flat screen (non-immersive), through projection walls (semi-immersive), to a head-mounted display with 360° tracking (fully immersive).

In: Emerging Technologies

Antibody–antigen aggregates that can lodge in the stria vascularis microvasculature, obstructing capillaries and causing ischaemic inner-ear injury — a prominent mechanism in lupus.

In: Autoimmune Inner Ear Disease

Window rupture from without — a surge of middle-ear pressure (e.g. forceful Valsalva, barotrauma) pushes the window membrane inward until it tears (Goodhill).

In: Perilymphatic Fistula

Mnemonic for the central HINTS pattern: Impulse Normal, Fast-phase Alternating (direction-changing nystagmus), Refixation on Cover Test (skew). Any one suggests stroke.

In: Vestibular Neuritis & Labyrinthitis

Inferior division of the vestibular nerve, carrying afferents from the posterior semicircular canal and the saccule. Less commonly affected in vestibular neuritis (~5–15% of cases), but selective inferior-division neuritis produces a distinctive pattern: normal head impulse, normal caloric, but absent cVEMP.

In: Vestibular Neuritis & Labyrinthitis, Pathophysiology, vHIT

A miniature inner-ear tissue grown from pluripotent stem cells containing functional hair cells — a platform for studying and, potentially, regenerating the vestibular periphery.

In: Emerging Technologies

A quantitative measure of side-to-side VEMP amplitude difference, calculated by the Jongkees formula: 100 × |L − R| / (L + R). IAR > 35% is generally considered abnormal and suggests asymmetric saccular or inferior vestibular nerve function.

In: Cervicogenic Dizziness

The period between attacks. Many VM patients have subtle interictal imbalance or visually-induced dizziness.

In: Vestibular Migraine

Bony canal in the petrous temporal bone transmitting the facial nerve, the cochlear nerve, and the two divisions of the vestibular nerve from the cerebellopontine angle to the inner ear. The site at which most vestibular schwannomas arise; MRI of the IAC with gadolinium is the gold-standard imaging.

In: Imaging, Pathophysiology

Failure of conjugate horizontal gaze caused by a lesion of the medial longitudinal fasciculus (MLF) — the ipsilateral eye fails to adduct on lateral gaze, with abducting nystagmus in the contralateral eye. Convergence is preserved (the diagnostic discriminator from a third-nerve lesion). Bilateral INO in a young patient strongly suggests MS.

In: Central Causes, Neuro-Ophthalmology, Pathophysiology

Midbrain integrator for vertical and torsional eye position, located in the rostral midbrain near the rostral interstitial nucleus of the medial longitudinal fasciculus. Lesions cause contraversive OTR and SVV tilt.

In: Neuro-Ophthalmology, Subjective Visual Vertical

Real-time monitoring of facial-nerve EMG and auditory responses during surgery to protect nerve function — now standard in vestibular and skull-base procedures.

In: Surgical Management

Steroid (commonly dexamethasone) delivered across the round-window membrane, giving high local concentration with low systemic toxicity — an alternative or adjunct when systemic steroids are unsuitable.

In: Autoimmune Inner Ear Disease

Transtympanic injection of dilute gadolinium that diffuses into the perilymph over ~24 hours, enabling delayed-3D-FLAIR visualisation of endolymphatic hydrops without systemic contrast.

In: Imaging

An aminoglycoside instilled into the middle ear to chemically ablate vestibular hair cells in refractory Ménière's vertigo (> 85% control), carrying a risk of hearing loss and persistent imbalance.

In: Ménière's Disease, Pharmacology

Delivery of a drug across the round-window membrane directly into the inner ear, minimising systemic exposure. Used in refractory Ménière's disease — corticosteroid (hearing-sparing) or gentamicin (chemical ablation).

In: Ménière's Disease, Pharmacology

A test of cervical proprioceptive accuracy in which the blindfolded patient is asked to return their head to a remembered neutral position after rotation. Error >4.5° on cervical rotation (Revel 1991) is considered abnormal and is reproducibly elevated in cervicogenic dizziness, more so on the side of greatest proprioceptive disturbance.

In: Cervicogenic Dizziness

Originally for caloric responses: UW = ((R-warm + R-cool) − (L-warm + L-cool)) / Σ × 100. The same arithmetic is used for symmetry in RCT.

In: Rotational Chair

The membranous balance organ within the temporal bone, comprising three semicircular canals (anterior, posterior, lateral) sensing angular acceleration and two otolith organs (utricle, saccule) sensing linear acceleration and head tilt. Together they generate the labyrinthine signal that integrates with cervical and visual input in the vestibular nuclei.

In: Cervicogenic Dizziness

Ablation of the vestibular end-organs through a transmastoid approach — the most reliable vertigo control (>95%) but sacrifices all hearing on that side; reserved for non-serviceable ears.

In: Surgical Management

Terminal branch of AICA supplying the inner ear (cochlea and labyrinth). Acute labyrinthine artery infarction causes simultaneous sudden hearing loss and vertigo — the hallmark of AICA stroke, captured by the hearing component of HINTS-Plus.

In: Pathophysiology

Inflammation involving both the vestibular and cochlear portions of the labyrinth, so that acute vertigo is accompanied by sensorineural hearing loss and tinnitus. May be serous (viral), suppurative (bacterial), or autoimmune.

In: Bedside Clinical Tests, Emergency Management, History Taking, Imaging, Vestibular Neuritis & Labyrinthitis, vHIT

Ossification of the cochlea and vestibule following bacterial labyrinthitis or meningitis. HRCT shows loss of fluid signal and bony obliteration — early recognition is critical for cochlear implant planning.

In: Imaging

Vertical canal plane containing the left anterior and right posterior canals. Tested by pitching the head 35–45° down or up in the plane oriented 45° from sagittal.

In: vHIT

The 1–5 second delay between reaching the provocative position and the onset of vertigo and nystagmus — the time free otoconia take to move. A hallmark of canalithiasis; central lesions lack it.

In: BPPV

BPPV variant involving the lateral (horizontal) semicircular canal. Produces direction-changing horizontal nystagmus on supine roll testing. Geotropic variant (canalithiasis) responds to the Lempert barbecue roll; apogeotropic (cupulolithiasis) is treated with Gufoni or modified manoeuvres.

In: Cervicogenic Dizziness

Treatment manoeuvre for horizontal-canal BPPV: sequential 90° head rolls toward the unaffected ear. Pair with Gufoni when the diagnosis is geotropic versus apogeotropic.

In: Setting Up a Vertigo Clinic, Emergency Management

First-line therapeutic manoeuvre for geotropic lateral canal BPPV. The patient is rolled 270° around the long axis (in 90° increments toward the unaffected side) to flush otoconia out of the lateral canal and back into the utricle.

In: Cervicogenic Dizziness

An unusual variant in which hearing and tinnitus improve as the vertigo begins — the reverse of the usual sequence.

In: Ménière's Disease

A transient electric-shock sensation radiating down the spine on neck flexion, classically from cervical-cord demyelination. A supportive clue to multiple sclerosis when it accompanies central vertigo.

In: Central Causes

Loss greatest at 250–1000 Hz — the early audiometric signature of Ménière's, giving a rising audiogram that recovers between attacks.

In: Ménière's Disease

Algorithms trained on vestibular test and imaging data to separate central from peripheral causes and support triage, approaching expert accuracy in research settings.

In: Emerging Technologies

Sensory epithelium of the otolith organs (saccule and utricle). Hair cells in the macula project stereocilia into the otoconial membrane, which is loaded with calcium carbonate otoconia. Linear acceleration and gravity deflect the membrane, deflecting the hair-cell bundles.

In: Pathophysiology

A central disorder of persistent oscillatory self-motion (rocking, bobbing, swaying) lasting more than 48 hours, classically after a sea voyage, and characteristically eased — not worsened — by being back in passive motion.

In: Imaging, Mal de Débarquement Syndrome, Understanding Symptoms

The core mechanism of MdDS: the brain adapts its vestibular processing to the rhythmic motion of a boat, then fails to readapt to stable ground — leaving a persistent internal sense of rocking.

In: Mal de Débarquement Syndrome

The diagnostic framework for multiple sclerosis, requiring dissemination in space and time. CSF-specific oligoclonal bands can now substitute for dissemination in time, allowing earlier diagnosis.

In: Central Causes

White-matter tract in the brainstem that connects the abducens nucleus (pons) with the contralateral oculomotor nucleus (midbrain), yoking the lateral rectus to the contralateral medial rectus during conjugate horizontal gaze. Demyelination produces INO; bilateral MLF involvement produces bilateral INO (WEBINO).

In: Central Causes, Neuro-Ophthalmology, Pathophysiology

Episodic vertigo with fluctuating low-frequency hearing loss, aural fullness, and tinnitus. Associated with endolymphatic hydrops. Vestibular function tests often show caloric–vHIT dissociation.

In: vHIT

Inner-ear disorder characterised by recurrent attacks of vertigo (20 min–12 h) with fluctuating low-frequency sensorineural hearing loss, tinnitus, and aural fullness — the 2015 Bárány/AAO-HNS definite criteria. Histopathological substrate is endolymphatic hydrops.

In: Setting Up a Vertigo Clinic, Emergency Management, History Taking, Imaging, Ménière's Disease, Pathophysiology, Understanding Symptoms, Vestibular Migraine

The best-studied steroid-sparing immunosuppressant in AIED, used in weekly low doses to maintain remission and reduce corticosteroid dependency.

In: Autoimmune Inner Ear Disease

Three-word recall plus clock-drawing screen (0–5 total) for cognitive impairment. ≤ 2 flags a positive screen; in dizzy elderly, the result frequently reshapes the work-up around geriatric assessment rather than vestibular testing.

In: Bedside Clinical Tests

Four-condition balance test (eyes open / closed × firm / foam surface) that probes the relative weighting of visual, vestibular and somatosensory inputs. Free, validated, and quick.

In: Setting Up a Vertigo Clinic

A congenital cochlear malformation associated with perilymphatic fistula and recurrent meningitis, presenting in childhood.

In: Perilymphatic Fistula

The near-paradoxical temporary reduction of MdDS symptoms during re-exposure to passive motion, e.g. while driving. A highly characteristic feature that separates MdDS from PPPD and other dizziness.

In: Mal de Débarquement Syndrome

Exaggerated dizziness provoked by complex or moving visual stimuli — scrolling screens, supermarket aisles, busy patterns. Common in vestibular migraine and PPPD.

In: History Taking, Vestibular Migraine

The classic subtype following passive motion (cruise, flight, long drive). It tends to have a better prognosis and to respond better to VOR readaptation than the spontaneous form.

In: Mal de Débarquement Syndrome

Vascular MRI — most often time-of-flight, contrast-free. Lower spatial resolution than CTA but avoids ionising radiation and iodinated contrast; less sensitive to subtle dissection or slow flow.

In: Imaging

The coordinated group — emergency, neurology, ENT/otology, audiology, vestibular physiotherapy, psychology, geriatrics, paediatrics, radiology and pharmacy — whose combined input manages complex vertigo.

In: Case-Based Discussion, Setting Up a Vertigo Clinic

Dizziness in older adults arising from the additive failure of several systems — vestibular, visual, proprioceptive, cardiovascular, medication-related and central — rather than a single diagnosis; a geriatric syndrome.

In: Paediatric & Elderly

Demyelinating disease of the central nervous system. Vestibular manifestations include INO, gaze-evoked nystagmus, downbeat nystagmus, periodic alternating nystagmus, and cerebellar ataxia. Diagnosis follows the McDonald criteria — most recent revision 2024 (Montalbán et al.) recognises the optic nerve as a fifth topographic site for DIS.

In: Neuro-Ophthalmology, Pathophysiology

The brain's combining of visual, vestibular, and proprioceptive inputs to maintain balance and orientation.

In: Understanding Symptoms

An acetylcholine receptor in the vestibular nuclei, reticular formation and CTZ. Anticholinergics such as scopolamine block it to reduce motion sickness — at the cost of central anticholinergic side effects.

In: Pharmacology

A stretch-sensitive sensory receptor embedded within skeletal muscle. The deep suboccipital muscles carry the highest density of muscle spindles in the body — up to 200 spindles per gram — making them the dominant cervical proprioceptive source. Spindle dysfunction underpins the proprioceptive mismatch of Route 1.

In: Cervicogenic Dizziness

A 10-section patient-reported outcome measuring neck-pain-related disability (Vernon & Mior 1991). Raw 0–50 (or 0–100% doubled). Bands: 0–4 none, 5–14 mild, 15–24 moderate, 25–34 severe, ≥35 complete. MCID ≈ 5 raw points. Useful as a baseline and for tracking change.

In: Cervicogenic Dizziness

The brainstem–cerebellar circuit (nucleus prepositus hypoglossi, medial vestibular nucleus, flocculus) that converts eye-velocity commands into the tonic position signal needed to hold gaze. Its failure produces gaze-evoked nystagmus.

In: Neuro-Ophthalmology

The interface of neurology and ophthalmology concerned with vision and eye movement controlled by the nervous system — here, the ocular-motor signs that localise vestibular lesions.

In: Neuro-Ophthalmology

A blood/CSF biomarker of axonal injury under study to support diagnosis and monitoring of central vestibular disease such as multiple sclerosis.

In: Emerging Technologies

Altering nervous-system activity with stimulation. In vertigo this includes repetitive TMS, transcranial direct-current stimulation and galvanic vestibular stimulation — largely experimental.

In: Emerging Technologies

A validated 12-item questionnaire that quantifies symptom severity across the three exacerbating factors and tracks change with treatment.

In: PPPD

Midline vestibulocerebellar lobules governing velocity storage and the processing of gravity-dependent (otolithic) signals. Their dysfunction underlies central positional and periodic alternating nystagmus.

In: Neuro-Ophthalmology

First-line imaging in suspected stroke to exclude haemorrhage before thrombolysis. Poor for posterior-fossa infarction; cannot exclude ischaemic stroke.

In: Emergency Management

Vague, ill-defined sensations — light-headedness, wooziness, disconnection — often from psychiatric or metabolic causes.

In: Understanding Symptoms

Involuntary rhythmic eye movement with a slow and a fast phase. Direction conventionally named after the fast phase. Pattern (horizontal/vertical/torsional, unidirectional/direction-changing, fixation-suppressed or not, gaze-evoked, positional) localises the lesion and distinguishes peripheral from central pathology.

In: Bedside Clinical Tests, History Taking, Neuro-Ophthalmology, Pathophysiology, vHIT

Triad of head tilt, skew deviation, and ocular counter-roll, all toward the same side. Indicates a lesion of the graviceptive pathway from the utricle to the interstitial nucleus of Cajal. SVV tilts toward the lower (hypotropic) eye in peripheral and pontomedullary lesions; tilts to the contralesional side in pontomesencephalic lesions above the decussation.

In: Neuro-Ophthalmology, Subjective Visual Vertical

Passive head rotation evoking compensatory eye movement via the VOR. In supranuclear gaze palsy these reflexive movements are preserved even though voluntary gaze is lost — confirming the lesion is above the ocular-motor nuclei.

In: Neuro-Ophthalmology

Bands of immunoglobulin present in CSF but not in matched serum, indicating intrathecal IgG synthesis. Found in ~85–95% of clinically definite MS and used as a supportive criterion.

In: Central Causes

A pontine lesion of the PPRF/abducens nucleus plus the adjacent MLF: an ipsilateral horizontal gaze palsy combined with an INO, leaving only contralateral abduction. Adding a facial palsy gives the 'eight-and-a-half' syndrome.

In: Neuro-Ophthalmology

Recurring annual costs — staff salaries, consumables, service contracts, software licences, rehab materials. Often underestimated by a factor of two in first-year budgets.

In: Setting Up a Vertigo Clinic

Back-to-back conjugate saccades occurring in all directions without an intersaccadic interval — a pathological extension of ocular flutter. In children classically signals neuroblastoma (opsoclonus-myoclonus-ataxia syndrome); in adults usually indicates paraneoplastic syndromes or post-infectious encephalitis. Often coexists with square-wave jerks and ocular flutter.

In: Neuro-Ophthalmology, Pathophysiology

Visual rehabilitation using moving visual patterns to reduce visual vertigo by retraining the visual–vestibular system.

In: Understanding Symptoms

Fall of ≥20 mmHg systolic or ≥10 mmHg diastolic blood pressure within three minutes of standing. A common, often missed mimic of vestibular vertigo, especially in older adults and patients on antihypertensives.

In: Bedside Clinical Tests, Paediatric & Elderly

Non-spinning vertigo experienced as continuous rocking, bobbing or swaying — as though still on a boat. The defining symptom of MdDS, distinct from rotational (spinning) vertigo.

In: Mal de Débarquement Syndrome

The illusion that the stationary visual world is moving or bouncing, typically during head movement. It reflects inadequate gaze stabilisation — from VOR failure (bilateral vestibulopathy) or pathological nystagmus.

In: Bilateral Vestibulopathy, History Taking, Neuro-Ophthalmology, Paediatric & Elderly, SSCD, vHIT, Vestibular Rehabilitation

Middle-ear fluid that, beyond hearing loss, can transiently impair balance and motor development in young children; ventilation tubes may improve both.

In: Paediatric & Elderly

Calcium carbonate crystals embedded in the otoconial membrane overlying the saccular and utricular maculae. Their density makes the otolith organs gravity-sensitive. Displaced otoconia drifting into a semicircular canal cause BPPV (canalithiasis).

In: BPPV, History Taking, Therapeutic Manoeuvres, Pathophysiology

Collective term for the utricle and saccule. Tested clinically with VEMPs (cervical and ocular).

In: vHIT

Bony otic capsule disease, most commonly causing stapedial fixation and a low-frequency conductive hearing loss with a Carhart notch at 2 kHz. Acoustic reflexes are absent on the affected side. The diagnostic look-alike for SCDS — preserved acoustic reflexes and supranormal bone conduction distinguish SCDS from otosclerosis.

In: Pathophysiology, SSCD

The window occupied by the stapes footplate. A fistula here is a recognised cause of vertigo and hearing loss after stapes surgery.

In: Perilymphatic Fistula

Vestibular-evoked myogenic potential recorded from the inferior oblique muscle (just below the eye) in response to acoustic or vibratory stimulation. Measures the utricle–superior vestibular nerve–ocular reflex. Reduced or absent in superior vestibular neuritis; enhanced in SCDS.

In: Pathophysiology

A corrective saccade that occurs after the head has returned to rest (typically > 220 ms). Visible at the bedside and a marker of acute, uncompensated VOR deficit.

In: vHIT

The pontine generator of ipsilateral horizontal saccades, projecting to the adjacent abducens nucleus. Its lesion causes a horizontal gaze palsy; combined with an MLF lesion it produces the one-and-a-half syndrome.

In: Neuro-Ophthalmology

Immune-mediated subacute cerebellar syndrome triggered by an underlying (often occult) cancer. Anti-Yo (ovarian, breast), anti-Hu (small-cell lung), anti-Tr (Hodgkin), and anti-Ri (breast, lung) are the canonical antibodies. The neurological syndrome frequently precedes the cancer diagnosis. PNS-Care 2021 criteria standardise diagnosis.

In: Pathophysiology

Multisensory cortical region (posterior insula, parietal operculum) that integrates vestibular, visual and somatosensory input. Functional imaging shows altered PIVC activity in PPPD, vestibular migraine and MdDS.

In: Imaging

Coordination drift test: with eyes closed, the patient raises an arm overhead and lowers it to touch the examiner's finger. Consistent drift toward one side suggests ipsilateral peripheral vestibular hypofunction; asymmetric overshoot suggests cerebellar dysmetria.

In: Bedside Clinical Tests

Distribution of patient funding sources — out-of-pocket, public insurance, private insurance, employer schemes. Affects pricing strategy and the operating margin.

In: Setting Up a Vertigo Clinic

High-sodium fluid filling the bony labyrinth between the endolymph and the periosteum. Perilymph and endolymph are separated by the membranous labyrinth. A communication between perilymph and the middle ear is a perilymph fistula.

In: Ménière's Disease, Pathophysiology, Perilymphatic Fistula

Abnormal communication between the perilymph-filled inner ear and the middle ear, typically at the oval or round window. Causes fluctuating sensorineural hearing loss and vertigo, often triggered by barotrauma, head injury, or surgery. Cochlin-tomoprotein (CTP) is a perilymph-specific biomarker with ~95% specificity in confirmed cases.

In: Bedside Clinical Tests, History Taking, Pathophysiology, Surgical Management

An abnormal communication between the perilymph-filled inner ear and the air-filled middle ear, usually at the round or oval window, allowing perilymph leak and abnormal pressure transmission — producing fluctuating hearing loss and vertigo.

In: Imaging, Perilymphatic Fistula

Horizontal nystagmus that changes direction every 90–120 seconds — right-beating for two minutes, briefly null, then left-beating for two minutes, and so on. Pathognomonic of nodular (vestibulocerebellar) pathology. Suppressed by baclofen, which is the established symptomatic treatment.

In: Pathophysiology

HINTS pattern indicating peripheral rather than central cause: abnormal head impulse on the affected side, unidirectional fixation-suppressed nystagmus, and no skew. Sensitivity 100% and specificity 96% for peripheral cause when all three components agree.

In: Pathophysiology

Vertigo from the labyrinth or vestibular nerve. Its nystagmus is unidirectional and horizontal-torsional, obeys Alexander's law, is suppressed by fixation, and is accompanied by a positive head impulse test — without other neuro-ophthalmological signs.

In: Bedside Clinical Tests, Neuro-Ophthalmology, Understanding Symptoms

Persistent (≥3 months) non-vertiginous dizziness or unsteadiness, exacerbated by upright posture, motion, and exposure to busy visual environments (Staab 2017 criteria). Often follows an acute vestibular event. First-line pharmacotherapy is an SSRI or SNRI; vestibular rehabilitation with graded exposure is the cornerstone.

In: Bedside Clinical Tests, Cervicogenic Dizziness, Setting Up a Vertigo Clinic, History Taking, Imaging, Mal de Débarquement Syndrome, Vestibular Neuritis & Labyrinthitis, Pharmacology, PPPD, Understanding Symptoms, Vestibular Rehabilitation

Phase is positive (lead) when eye velocity peaks before chair velocity. In normals phase lead is large at low frequencies and approaches zero above 0.16 Hz. Elevated phase lead at all frequencies suggests peripheral hypofunction; reduced phase lead suggests over-active velocity storage.

In: Rotational Chair

Brandt and Dieterich's syndrome of subjective unsteadiness with normal examination, often attack-like and situation-bound — one of the historical precursors that were unified into PPPD.

In: PPPD

Abnormal sensitivity to sound during an attack — distinct from the loudness discomfort of recruitment in cochlear disease.

In: Vestibular Migraine

Abnormal sensitivity to light. With phonophobia, it is one of the migrainous features that can satisfy criterion C.

In: Vestibular Migraine

The combination of light and sound sensitivity during a vestibular episode; together they count as one migrainous feature.

In: Vestibular Migraine

Branch of the vertebral artery supplying the dorsolateral medulla and inferior cerebellum. Occlusion causes lateral medullary (Wallenberg) syndrome or isolated cerebellar infarction; hearing is usually spared.

In: Central Causes

Cerebellar/lateral medullary stroke. vHIT often shows symmetric mild bilateral gain reduction with very small saccades — the central pattern.

In: vHIT

Infarct in the posterior inferior cerebellar artery territory — lateral medullary syndrome with vertigo, dysphagia, Horner, ipsilateral facial/contralateral body sensory loss.

In: Emergency Management

Air within the membranous labyrinth — pathognomonic of a perilymphatic fistula. Identified on HRCT after head or barotrauma; direct visualisation of the fistula itself is rare.

In: Imaging, Perilymphatic Fistula

Concurrent use of multiple medications. Sedatives, antihypertensives, anticholinergics and prolonged vestibular suppressants are a frequent, reversible cause of dizziness and falls in older adults.

In: Paediatric & Elderly

An oblique CT reconstruction plane perpendicular to the long axis of the superior semicircular canal. Indispensable for confidently calling — or excluding — superior canal dehiscence; axial-only review over-diagnoses.

In: Imaging, SSCD

Nystagmus provoked by a change in head or body position. Peripheral (BPPV) forms show latency, a crescendo course, and fatigue; central forms are immediate, persistent, and often direction-changing.

In: Neuro-Ophthalmology

Nuclear-medicine imaging of metabolic activity using radiotracers (most commonly ¹⁸F-FDG). Used in research for chronic functional vestibular disorders (MdDS, PPPD) and clinically for skull-base and temporal-bone neoplasms.

In: Imaging

The most common BPPV variant. Otoconia in the posterior semicircular canal produce brief upbeating-torsional nystagmus on Dix-Hallpike. Responds to Epley repositioning, with single-session success around 80%.

In: Bedside Clinical Tests, Cervicogenic Dizziness, Emergency Management

The vertebrobasilar arterial system — vertebral arteries, basilar artery and their branches (PICA, AICA, SCA) — supplying the brainstem, cerebellum, thalamus and occipital lobes. Around 20% of ischaemic strokes occur here.

In: Central Causes

Ischaemic stroke in the vertebrobasilar territory — affecting the brainstem, cerebellum, posterior cerebral hemispheres, or terminal branches such as the labyrinthine artery. May present with isolated vertigo. DWI MRI has 80–88% sensitivity within the first 48 hours; the HINTS examination outperforms early MRI for central vs peripheral discrimination.

In: Emergency Management, Pathophysiology

The compartment of the skull base housing the brainstem and cerebellum. Tumours, infarcts and haemorrhage here can cause vertigo and threaten the fourth ventricle, risking obstructive hydrocephalus and brainstem compression.

In: Central Causes

A sustained fall in blood pressure on standing (≥20 mmHg systolic or ≥10 mmHg diastolic), leading to presyncope; common in the elderly or on antihypertensives.

In: Understanding Symptoms

Sustained heart-rate rise of ≥30 bpm (≥40 bpm in adolescents) on standing without orthostatic hypotension. Presents as chronic light-headedness and exercise intolerance.

In: Bedside Clinical Tests

Chronic functional vestibular disorder. Symptoms (dizziness, unsteadiness, or non-spinning vertigo) on ≥15 days per month for ≥3 months, exacerbated by upright posture, motion, and complex visual stimuli — all three required by Bárány 2017 criteria. Treatment: CBT, vestibular rehabilitation, and SSRIs.

In: Pathophysiology

The acute or episodic trigger that commonly initiates PPPD — vestibular neuritis or BPPV, vestibular migraine, a panic attack, whiplash or concussion, or another medical event causing dizziness.

In: PPPD

Age-related mild bilateral vestibular hypofunction (Bárány Society 2019 criteria): a chronic vestibular syndrome in someone ≥60 with objectively reduced function (e.g. vHIT gain 0.6–0.8) not better explained otherwise.

In: History Taking, Paediatric & Elderly

A sensation of impending faint, usually cardiovascular in origin (orthostatic hypotension, arrhythmia). It is commonly mislabelled as dizziness but is not true vertigo.

In: History Taking, Understanding Symptoms

The Bárány category for patients who have the vestibular episodes and one — but not both — of the migraine criteria (a migraine history, or migrainous features during attacks). A legitimate working diagnosis, often re-classified over time.

In: Vestibular Migraine

A tauopathy presenting with vertical supranuclear gaze palsy (early downgaze limitation), slowed saccades, postural instability with falls, and axial rigidity. Unsteadiness often predates the eye signs by months.

In: Neuro-Ophthalmology

Bedside sign of upper motor neuron weakness: with arms outstretched, palms up, and eyes closed, the affected arm drifts downward and pronates. A red flag for central pathology in the dizzy patient.

In: Bedside Clinical Tests

Daily treatment aimed at reducing attack frequency and severity — lifestyle/trigger management plus, where needed, agents such as propranolol, amitriptyline, topiramate or flunarizine.

In: Vestibular Migraine

The sense of self-position and movement of body parts in space, derived primarily from muscle spindles, Golgi tendon organs, and joint receptors. Cervical proprioception is dominated by the deep suboccipital muscles and is the foundation of the proprioceptive cervicogenic mechanism (Route 1).

In: Cervicogenic Dizziness, Understanding Symptoms

Impaired joint-position sense and spatial orientation, contributing to imbalance and disequilibrium — particularly in older adults and those with peripheral neuropathy.

In: History Taking

Paired canals on opposite sides of the head sense the same angular rotation in opposite directions. Excitation of one drives the VOR; the contralateral canal is inhibited.

In: vHIT

Vertical canal plane containing the right anterior and left posterior canals.

In: vHIT

Reactivation of varicella-zoster virus affecting the facial and vestibulocochlear nerves, presenting with vertigo, hearing loss, facial palsy, and a vesicular rash in the ear canal.

In: History Taking

Clinical features that signal a potentially serious or central cause of vertigo: focal neurological deficits, vertical or direction-changing nystagmus, acute hearing loss with facial palsy, or symptoms refractory to treatment. Any of these mandates urgent imaging and referral.

In: Case-Based Discussion, History Taking

Documented route by which primary care, ED or stroke teams can refer to the clinic — single phone/SMS/email lane, agreed turnaround. Friction kills referrals more than diagnostic quality does.

In: Setting Up a Vertigo Clinic

The thin membrane separating endolymph (scala media) from perilymph (scala vestibuli). It bulges with hydrops and may rupture, mixing the fluids — one proposed mechanism of an attack.

In: Ménière's Disease

Non-invasive magnetic stimulation that modulates cortical excitability; trialled over the dorsolateral prefrontal cortex for mal de débarquement syndrome and functional dizziness.

In: Emerging Technologies, Mal de Débarquement Syndrome

Movement of the image across the retina when the VOR fails to fully stabilise gaze. It is the error signal that drives VOR adaptation.

In: Vestibular Rehabilitation

Postural-stability test. Patient stands with feet together, eyes open then closed. A positive sign — instability emerging only with eyes closed — indicates sensory ataxia from vestibular or dorsal-column dysfunction.

In: Bedside Clinical Tests, Bilateral Vestibulopathy, Understanding Symptoms

The midbrain burst-neuron generator for vertical and torsional saccades. Lesions impair vertical gaze and contribute to vertical supranuclear palsy, often alongside thalamic-mesencephalic infarcts.

In: Neuro-Ophthalmology

Sinusoidal whole-body rotation in darkness that quantifies VOR gain and phase across mid frequencies. Low gain with a short time constant / abnormal phase at 0.1 Hz is part of the Bárány criteria.

In: Bilateral Vestibulopathy

Mechanical compression of the dominant vertebral artery on sustained head rotation, producing transient brainstem features that resolve on returning to neutral. Requires a structural compression source (osteophyte, fibrous band, atlantoaxial instability) and inadequate contralateral collateral flow. Manipulation is contraindicated.

In: Cervicogenic Dizziness

The membrane-covered window between the scala tympani and the middle ear — the most frequent site of a perilymphatic fistula.

In: Perilymphatic Fistula

Reinforcing the round window to dampen third-window energy transfer — a less invasive option of more variable and often less durable benefit than canal occlusion.

In: SSCD

A rapid, ballistic eye movement that re-fixates gaze on a target. Corrective saccades in vHIT compensate for an inadequate VOR.

In: vHIT

Inappropriate involuntary saccades that interrupt steady fixation — square-wave jerks, macrosaccadic oscillations, and opsoclonus — reflecting impaired cerebellar and brainstem fixation control.

In: Neuro-Ophthalmology

One of the two otolith organs in the vestibule, oriented vertically. Detects linear acceleration in the sagittal plane and gravity. Innervated by the inferior vestibular nerve; saccular function is tested with the cVEMP.

In: Pathophysiology, Subjective Visual Vertical, vHIT

Workflow model where history, bedside tests and (where possible) instrumented testing happen in a single visit. Reduces patient travel burden and improves throughput.

In: Setting Up a Vertigo Clinic

Fraction of new patients who leave the first visit with a working diagnosis (rather than a list of further investigations). Useful efficiency metric; target ≥70% for an established clinic.

In: Setting Up a Vertigo Clinic

The vestibular ganglion housing the cell bodies of the primary vestibular afferents — the site where latent herpes simplex virus is hypothesised to reactivate in vestibular neuritis.

In: Vestibular Neuritis & Labyrinthitis

Third-window disorder caused by absent bone over the superior semicircular canal. Sound and pressure stimuli are abnormally transmitted into the labyrinth, producing the clinical triad of autophony, Tullio phenomenon, and Hennebert sign. Audiogram shows low-frequency air-bone gap with supranormal bone conduction. Bárány Society 2021 diagnostic criteria.

In: Pathophysiology

BPPV following an identifiable cause — head trauma, vestibular neuritis, ear surgery or Ménière's disease — more often multi-canal, bilateral, or resistant to repositioning than idiopathic BPPV.

In: BPPV, Vestibular Neuritis & Labyrinthitis

A class of antidepressants effective in managing PPPD, MdDS, and psychogenic dizziness.

In: Understanding Symptoms

One of three fluid-filled canals in each labyrinth — anterior (superior), posterior, and lateral (horizontal) — oriented at right angles to detect angular acceleration in three planes. Each canal has an ampulla containing the crista ampullaris.

In: Pathophysiology, vHIT

Lateral (horizontal), anterior (superior) and posterior canals. The horizontal canal lies 30° above the earth-horizontal in upright posture, which is why the head is tilted 30° forward during RCT.

In: Rotational Chair

Alternative therapeutic manoeuvre for posterior canal BPPV using rapid lateral position changes rather than head rotation. Useful when cervical extension is limited or painful. Similar efficacy to Epley in network meta-analysis.

In: Cervicogenic Dizziness

The integrated process by which sensory information (proprioceptive, vestibular, visual) is processed centrally to produce coordinated motor output for posture and gaze. Cervical sensorimotor retraining — addressing JPE, oculomotor control, balance, and movement sense — is a Level-2-evidence cornerstone of Route 1 management (Sremakaew 2023).

In: Cervicogenic Dizziness

Hearing loss caused by cochlear or retrocochlear pathology, producing equal reductions in air-conduction and bone-conduction thresholds (no air-bone gap). Patterns include low-frequency rising (Ménière's), asymmetric high-frequency downsloping (schwannoma), or symmetric high-frequency (presbycusis).

In: Autoimmune Inner Ear Disease, Ménière's Disease, Paediatric & Elderly, Pathophysiology

A mismatch between visual, vestibular and proprioceptive cues. VR deliberately induces it to provoke symptoms for diagnosis and, with repeated exposure, to drive habituation and compensation.

In: Emerging Technologies

A computerised dynamic posturography protocol that scores postural sway across six conditions varying visual and proprioceptive feedback. Visual-preference patterns (abnormal in conditions 3 and 6, preserved 5) suggest central reweighting toward visual cues; pure proprioceptive deficit shows abnormal 4, 5, 6.

In: Cervicogenic Dizziness

The CDP protocol that measures balance across six conditions of altered or removed visual and proprioceptive input, revealing sensory dependence.

In: Vestibular Rehabilitation

Central rebalancing of how heavily the brain trusts visual, vestibular and proprioceptive cues for balance — retrained by varying surface and visual conditions.

In: Understanding Symptoms, Vestibular Rehabilitation

Rehabilitation strategy that trains greater use of vision and proprioception, plus saccadic and pursuit strategies, to compensate for absent vestibular input — central to managing severe BVP.

In: Bilateral Vestibulopathy

How the clinic delivers care: ENT-led, neurology-led or multidisciplinary; weekly half-day vs daily; embedded in an ENT department or standalone. Documents every subsequent decision.

In: Setting Up a Vertigo Clinic

Hearing good enough to be worth preserving (often defined as ≤50 dB pure-tone average and ≥50% speech discrimination). It is the pivotal decision axis — serviceable hearing favours hearing-sparing operations; non-serviceable hearing permits ablative ones.

In: Surgical Management

Romberg performed in tandem (heel-to-toe) stance. Narrowing the base of support increases sensitivity to subtle balance deficits and unmasks compensated unilateral vestibular loss.

In: Bedside Clinical Tests

vHIT variant introduced by MacDougall and Curthoys (2016). Patient fixates a head-fixed laser; healthy subjects generate an anti-compensatory saccade after the impulse. Reduced peak SHIMP saccade velocity indicates canal deficit.

In: vHIT

Use of controlled virtual environments (including VR) to simulate motion and treat visual vertigo or balance disorders.

In: Understanding Symptoms

A question format with one best option among plausible distractors. Each case here uses an SBA with a rationale for every option to model clinical reasoning.

In: Case-Based Discussion

The chair is oscillated sinusoidally across octave frequencies with vision denied. Gain, phase and symmetry are extracted at each frequency. SHA is the gold standard for bilateral vestibular loss.

In: Rotational Chair

Vertical misalignment of the eyes producing vertical refixation on alternate cover testing. A central sign localising to the brainstem or cerebellum, and one of the three components of the HINTS examination. Skew in the context of acute vestibular syndrome strongly suggests stroke.

In: Bedside Clinical Tests, Vestibular Neuritis & Labyrinthitis, Neuro-Ophthalmology, Pathophysiology, Subjective Visual Vertical, vHIT

The slow phase reflects the VOR drive; the fast phase is a brainstem-generated re-fixation saccade. SPV — not nystagmus frequency — is the metric used by every RCT calculation.

In: Rotational Chair

The eyes' ability to track a slowly moving target smoothly, depending on cortical eye fields, the cerebellar flocculus/vermis, and brainstem nuclei. Cerebellar or brainstem disease replaces it with catch-up (saccadic) pursuit.

In: Neuro-Ophthalmology

Measures smooth-pursuit gain in two conditions: head and trunk aligned, then trunk rotated 45° under a stationary head. A gain difference >0.10 between the two conditions implicates abnormal cervical afference, since the vestibular system is in the same position in both conditions.

In: Cervicogenic Dizziness

A structured history-taking framework for vertigo: Symptoms, Onset, Speed of onset, Triggers, Otological symptoms, Neurological symptoms, Evolution, and Duration.

In: History Taking

Opening the clinic to a single trusted referrer for 2–4 weeks before going to open access. Surfaces workflow defects with low blast radius.

In: Setting Up a Vertigo Clinic

Discomfort and disorientation provoked by environments with conflicting or sparse spatial cues (supermarket aisles, crowds, traffic) — a characteristic feature linked to visual dependence.

In: PPPD

Computed at each SHA frequency. A purity below ~60 % means the response is poorly described by a sinusoid (drowsiness, artefact, or sparse nystagmus) and the frequency should be re-tested.

In: Rotational Chair

Group of autosomal-dominant hereditary cerebellar ataxias, over 40 subtypes described. SCA1, 2, 3 (Machado-Joseph), and 6 account for about 60% of dominant cases worldwide. Most are CAG-repeat expansion disorders; onset typically third to sixth decade. SCA2 is notable for saccadic slowing.

In: Pathophysiology

The vermal and paravermal cerebellar zones that receive spinal cord afferents and control trunk and limb coordination. Anterior-vermis lesions produce gait ataxia with relatively preserved limb function (the classical alcoholic-cerebellar-degeneration pattern); posterior-vermis lesions produce truncal ataxia with inability to sit unsupported.

In: Pathophysiology

MdDS arising without a clear motion trigger, sometimes after stress or illness. It is more often associated with anxiety and migraine and tends to be more persistent and refractory.

In: Mal de Débarquement Syndrome

Recurrent episodes of vertigo that occur without an obvious trigger. Dominated by vestibular migraine and Ménière's disease, with vertebrobasilar TIA the can't-miss central cause.

In: Case-Based Discussion, Emergency Management

Nystagmus present at rest in primary gaze. Peripheral forms are unidirectional, horizontal-torsional, fixation-suppressed, and obey Alexander's law; central forms can be vertical, purely torsional, or direction-changing and resist fixation.

In: Bedside Clinical Tests, Emergency Management, History Taking, Neuro-Ophthalmology

Cervical extension and lateral flexion toward the symptomatic side with axial compression. Reproduction of radicular pain suggests cervical nerve root compression. A negative test argues against radiculopathy but does not address proprioceptive cervicogenic dizziness mechanisms.

In: Cervicogenic Dizziness

Small horizontal saccades (0.5–5°) that move the eyes off fixation and bring them back after a brief intersaccadic interval of about 200 ms. A few per minute are normal; frequent (≥ 10/min) square-wave jerks indicate cerebellar pathology or, less commonly, progressive supranuclear palsy. Their pathological extension without intersaccadic interval is ocular flutter (and opsoclonus when multidirectional).

In: Neuro-Ophthalmology, Pathophysiology

Selective serotonin (and noradrenaline) reuptake inhibitors. First-line pharmacotherapy for PPPD, reducing vestibulo-visual hypersensitivity and motion-triggered anxiety; benefit takes 4–6 weeks.

In: Pharmacology, PPPD

Structured history-taking framework (e.g., TiTrATE, SO STONED) that captures Timing, Triggers, Associated symptoms, Targeted examination, and Evaluation. Reduces variance across clinicians.

In: Setting Up a Vertigo Clinic

Oblique CT reconstruction parallel to the long axis of the petrous bone and the superior canal — a complementary view to Pöschl that profiles the canal in its long axis.

In: Imaging, SSCD

After a rapid acceleration to constant velocity the SPV decays exponentially; the same occurs after deceleration to a stop. Per-rotational and post-rotational Tc are compared.

In: Rotational Chair

Actin-cored microvilli on the apical surface of hair cells, arranged in graded staircase rows. Mechanotransduction occurs when stereocilia are deflected toward the tallest row (the kinocilium in vestibular hair cells), tip-link tension opens cation channels, and the cell depolarises.

In: Pathophysiology

Improvement in hearing and vertigo with corticosteroids — both a diagnostic clue and a treatment goal in AIED, since the diagnosis lacks a confirmatory test.

In: Autoimmune Inner Ear Disease

Positional test for anterior-canal BPPV. Supine, the head is extended 30–45° below the horizontal in the midline; provokes transient downbeating-torsional nystagmus when AC-BPPV is present.

In: Bedside Clinical Tests

Same paradigm as SVV but with the perceived horizontal axis. Test–retest reliability and disease sensitivity are comparable to SVV; the two are typically orthogonal and used interchangeably in most labs.

In: Subjective Visual Vertical

The angle a person perceives as upright when adjusting a luminous line in an otherwise dark environment. Reflects central integration of otolith (graviceptive) input, ocular counter-roll, and visual cues. Normal range in healthy adults is roughly ±2° from true earth-vertical.

In: Neuro-Ophthalmology, Subjective Visual Vertical

The four deep posterior muscles connecting the upper cervical vertebrae to the occiput: rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, obliquus capitis inferior. They contribute about half of cervical rotation at C1–C2 and carry the densest proprioceptive afference in the cervical spine.

In: Cervicogenic Dizziness

A compensatory strategy that trains alternative sensory systems (vision, proprioception) and alternative eye movements (saccades) to replace deficient vestibular input.

In: Vestibular Rehabilitation

≥30 dB SNHL across three contiguous frequencies developing in ≤72 h. When paired with acute vertigo, an AICA-stroke red flag — but high-dose steroid within 14 days improves outcome.

In: Emergency Management

Absence of the bony roof over the superior semicircular canal, creating a third window into the membranous labyrinth. Presents with sound- or pressure-induced vertigo (Tullio, Hennebert), autophony, pulsatile tinnitus, and characteristically low VEMP thresholds.

In: Bedside Clinical Tests, History Taking

Third-window syndrome with autophony, sound- or pressure-induced vertigo (Tullio, Hennebert) and a low-threshold cVEMP. Work-up needs VEMP and temporal-bone CT; surgical when disabling.

In: Setting Up a Vertigo Clinic

A bony defect in the roof of the superior canal that creates a third mobile window — sound- or pressure-induced vertigo (Tullio, Hennebert), autophony and pseudoconductive hearing loss. HRCT in the Pöschl plane is diagnostic.

In: Imaging, SSCD, Surgical Management

Superior division of the vestibular nerve, carrying afferents from the lateral and superior semicircular canals and the utricle. Most commonly affected division in vestibular neuritis. Function is tested with the head impulse, caloric, and oVEMP.

In: Vestibular Neuritis & Labyrinthitis, Pathophysiology, vHIT

The diagnostic test for lateral canal BPPV. The patient lies supine with the head flexed 30° (placing the lateral canal in the vertical plane), then the head is rapidly rolled 90° to each side. Direction of provoked nystagmus distinguishes geotropic (toward the earth — canalithiasis) from apogeotropic (toward the ceiling — cupulolithiasis) variants.

In: Bedside Clinical Tests, BPPV, Cervicogenic Dizziness, Therapeutic Manoeuvres

Loss of voluntary gaze with preserved reflex (vestibulo-ocular, oculocephalic) eye movements, from lesions above the ocular-motor nuclei — cortical eye fields, riMLF, PPRF, or their pathways. Vertical forms typify PSP.

In: Neuro-Ophthalmology

Computed as (peakR − peakL)/(peakR + peakL) × 100. Values within ±22 % are normal. Larger values usually indicate an uncompensated unilateral lesion or an irritative state.

In: Rotational Chair

Patient walks heel-to-toe along a straight line. Inability or instability suggests cerebellar disease, vestibular hypofunction, or functional gait disorder; the pattern (wide-based, cautious, or freezing) refines the differential.

In: Bedside Clinical Tests

Agreed price for a defined procedure (e.g., VNG, vHIT, vestibular rehab session). Coding accuracy determines cost recovery; under-coding is a quiet but constant revenue leak.

In: Setting Up a Vertigo Clinic

Vertical ocular misalignment revealed by the alternate cover test. In acute vestibular syndrome a skew points to a brainstem (central) lesion and is part of the dangerous HINTS pattern.

In: Bedside Clinical Tests, Central Causes, Emergency Management, Neuro-Ophthalmology

Upright posture, active or passive self-motion (regardless of direction), and exposure to moving or complex visual stimuli — the trio that worsens PPPD and anchors criterion B.

In: PPPD

Any abnormal opening through the otic capsule that creates a low-impedance pathway for acoustic energy alongside the normal oval and round windows. SCDS is the prototype; other causes include large vestibular aqueduct, dehiscence of the posterior or lateral canal, and the X-linked DFN3 mixed hearing loss.

In: Bedside Clinical Tests, Pathophysiology, Surgical Management

Normally the inner ear has two windows (oval and round). A dehiscence adds a third, so acoustic and pressure energy is abnormally shunted — stimulating the canal and diverting sound from the cochlea.

In: SSCD

Time-critical intervention for ischaemic stroke (≤4.5 h from onset). Posterior-circulation strokes presenting with vertigo are commonly missed; HINTS is the triage gate.

In: Emergency Management

A diagnostic tool for presyncope and autonomic dysfunction, monitoring cardiovascular responses to changes in posture.

In: Understanding Symptoms

After a velocity step the SPV decays exponentially. The cupula alone gives Tc ≈ 4–6 s; the central velocity-storage integrator prolongs this to 12–25 s in normals. Tc shortens with peripheral loss and lengthens with central disinhibition.

In: Rotational Chair

Free, validated mobility test (Podsiadlo 1991) — stand from a chair, walk 3 m, turn, return, sit. >12 s flags fall risk in the elderly. Tracks rehab response.

In: Setting Up a Vertigo Clinic

Functional balance test. Patient rises from a chair, walks 3 m, turns, walks back and sits. >12 s predicts increased fall risk in older adults.

In: Bedside Clinical Tests, Vestibular Rehabilitation

Perceived sound without an external source; in Ménière's often a low-pitched roar that intensifies before an attack.

In: Ménière's Disease

Sealing the leaking window with autologous tissue — fat, perichondrium or temporalis fascia — the definitive surgical treatment.

In: Perilymphatic Fistula

A diagnostic framework for acute dizziness — Timing and Triggers point to a vestibular syndrome (acute, triggered-episodic, spontaneous-episodic or chronic), And a Targeted Examination confirms it. It anchors the case-based approach.

In: Case-Based Discussion, Imaging

Structured triage approach for the dizzy patient organising the assessment around Timing, Triggers and Targeted Examination. Yields three syndromes — triggered EVS, spontaneous EVS, and AVS — each with a different work-up.

In: Emergency Management

The brief, self-limited after-rocking that most people feel for hours after a voyage. It resolves within 48 hours and is a normal phenomenon — not the syndrome.

In: Mal de Débarquement Syndrome

A route to the internal auditory canal through the labyrinth, used to resect vestibular schwannomas in ears with non-serviceable hearing — excellent facial-nerve outcomes but sacrifices hearing and balance on that side.

In: Surgical Management

The trigeminal sensory innervation of cranial blood vessels. Its activation and the release of neuropeptides (including CGRP) drive migraine pain and can modulate central vestibular pathways.

In: Vestibular Migraine

Brief, recurrent vertigo provoked by a trigger — positional (BPPV) or on standing (orthostatic hypotension). Defined by the trigger, not just the timing.

In: Case-Based Discussion, Emergency Management

Vertigo or eye movement induced by loud sound — a feature of third-window disorders (SCDS), perilymph fistula, and rarely Ménière's. Reflects abnormal acoustic energy transfer into the labyrinth through a third window.

In: Bedside Clinical Tests, Bedside Clinical Tests, History Taking, Imaging, Pathophysiology, Perilymphatic Fistula, SSCD

A sudden fall to the ground without warning or loss of consciousness, from an abrupt otolithic discharge. A late-stage feature and an indication to escalate treatment.

In: Ménière's Disease

Reduced vestibular function on one side (e.g. after neuritis). VRT exploits the intact side via VOR adaptation and balance retraining.

In: Vestibular Rehabilitation

A variant of the Fukuda stepping test; some sources use the names interchangeably. Tests vestibulospinal tone asymmetry by stepping in place with eyes closed.

In: Bedside Clinical Tests

Vertical nystagmus with fast phases beating upward, pointing to lesions of the pontomesencephalic junction, medulla, or anterior cerebellar vermis.

In: Bedside Clinical Tests, Neuro-Ophthalmology

Horizontally-oriented otolith organ that senses linear acceleration in the earth-horizontal plane and head tilt in the roll plane. The dominant graviceptor in upright stance; SVV tilt after unilateral vestibular loss is largely a utricular signal.

In: Therapeutic Manoeuvres, Pathophysiology, Subjective Visual Vertical, vHIT

A brainstem–nodulus mechanism that prolongs and integrates rotational vestibular signals beyond the canal afferents' time constant. Its dysregulation contributes to central positional and periodic alternating nystagmus.

In: Bilateral Vestibulopathy, Mal de Débarquement Syndrome, Neuro-Ophthalmology, Rotational Chair

Family of myogenic potentials evoked by acoustic or vibratory stimulation of the otolith organs. cVEMP (recorded from the sternocleidomastoid) tests the saccule and inferior vestibular nerve; oVEMP (recorded from inferior oblique) tests the utricle and superior vestibular nerve. Patterns of preservation and enhancement are diagnostic.

In: Vestibular Neuritis & Labyrinthitis, Pathophysiology, SSCD

The paired arteries running through the transverse foramina of C6 to C1, supplying the brainstem and posterior cerebral circulation. The V3 segment (between C2 and the foramen magnum) is the most mobile portion and is the typical site of mechanical compression in rotational vertebral artery syndrome (RVAS).

In: Cervicogenic Dizziness

Intramural haemorrhage within the wall of the vertebral artery, often following minor trauma or neck strain. Leading cause of posterior circulation stroke in patients under 50. Neck pain or trauma preceding vertigo is the classic historical clue; urgent CTA or MRA of the vertebral arteries is the investigation of choice.

In: Imaging, Pathophysiology

Transient ischaemia of the posterior circulation territory, often presenting as brief positional vertigo or recurrent dizziness in older adults with vascular risk factors. CTA/MRA defines the substrate (stenosis, hypoplasia, dissection).

In: Bedside Clinical Tests, Imaging

Transient ischaemia in the vertebrobasilar territory — recurrent brief vertigo with associated brainstem symptoms (diplopia, dysarthria, weakness). High-risk for completed stroke.

In: Emergency Management

A false sensation of self- or environmental motion, typically rotational, resulting from dysfunction of the peripheral or central vestibular system. It is a symptom, not a diagnosis.

In: History Taking

Deliberate destruction of vestibular function (chemically with gentamicin, or surgically) to abolish the abnormal signals driving vertigo; reserved for intractable disease.

In: Ménière's Disease

A rehabilitation strategy that retrains the brain to compensate for vestibular deficits through repeated, graded motion exposure.

In: Understanding Symptoms

Complete absence of a measurable vestibular response (e.g. no caloric response and absent vHIT VOR) — the severe end of the bilateral-vestibulopathy spectrum.

In: Bilateral Vestibulopathy

The neuroplastic process by which the brain recalibrates balance after asymmetric or lost vestibular input. It is the engine of recovery — and it is blunted by prolonged vestibular suppressants, which is why they must be stopped early.

In: Pharmacology

Short-latency myogenic potentials elicited by intense sound or vibration. Cervical VEMP (cVEMP, recorded from the sternocleidomastoid) tests the saccule and inferior vestibular nerve; ocular VEMP (oVEMP, recorded from inferior oblique) tests the utricle and superior vestibular nerve. Unilateral amplitude reduction localises to the saccule/inferior nerve pathway and warrants further investigation.

In: Cervicogenic Dizziness, Subjective Visual Vertical

Short-latency reflexes that probe otolith function — cervical VEMP for the saccule, ocular VEMP for the utricle. Required for confident superior canal dehiscence work-up.

In: Autoimmune Inner Ear Disease, Setting Up a Vertigo Clinic, Paediatric & Elderly

Loss of vestibular function in both labyrinths, typically presenting with chronic imbalance, oscillopsia, and difficulty walking in the dark or on uneven ground rather than acute spinning vertigo.

In: History Taking

A neuroprosthesis, analogous to a cochlear implant, that senses head motion and delivers encoded electrical stimulation to the ampullary (semicircular-canal) nerves to restore vestibular input in bilateral vestibulopathy. In early clinical testing.

In: Bilateral Vestibulopathy, Emerging Technologies, Surgical Management, Vestibular Rehabilitation

Discrete vestibular attacks (5 minutes to 72 hours) accompanied by migrainous features (photophobia, phonophobia, headache, aura) in a patient with a migraine history. The most commonly missed alternative explanation for the neck-pain-plus-dizziness presentation. Premonitory neck stiffness in the 24 hours before an attack is a recognised feature.

In: Cervicogenic Dizziness, Setting Up a Vertigo Clinic, Emergency Management, History Taking, Imaging, Neuro-Ophthalmology, Paediatric & Elderly, Pathophysiology, Pharmacology, Vestibular Migraine, vHIT

Selective division of the vestibular nerve, abolishing pathological input while sparing the cochlear nerve — definitive vertigo control (>90%) with hearing preservation, via a middle-fossa or retrosigmoid approach.

In: Surgical Management

Acute, persistent vestibular hypofunction from inflammation of the vestibular nerve. Continuous vertigo for days, peripheral HINTS pattern, no auditory symptoms. Bárány Society 2022 (Strupp et al.) renaming as acute unilateral vestibulopathy. Selective inferior-division involvement (5–15%) produces a distinctive pattern.

In: Bedside Clinical Tests, Cervicogenic Dizziness, Setting Up a Vertigo Clinic, Emergency Management, History Taking, Vestibular Neuritis & Labyrinthitis, Pathophysiology, Pharmacology, Understanding Symptoms

Four paired nuclei in the lateral medulla — superior, lateral (Deiters'), medial, and inferior. They receive vestibular afferents from the labyrinth, cervical afferents via the central cervical nucleus, and visual input, and they project to oculomotor nuclei (for the VOR), the spinal cord (vestibulospinal), and the cerebellum. The central integrator of head-position information.

In: Cervicogenic Dizziness

Exercise-based therapy combining gaze stabilisation, habituation and balance retraining. The most evidence-based intervention in the clinic for unilateral hypofunction and a key pillar of PPPD treatment.

In: Case-Based Discussion, Setting Up a Vertigo Clinic, PPPD

Dedicated open floor with grab rails, foam pads, gaze-stabilisation targets and (optionally) a VR rig. Plan from day one — vestibular rehab is the highest-evidence treatment in the clinic.

In: Setting Up a Vertigo Clinic

Exercise-based therapy that drives central compensation for vestibular loss through adaptation, substitution, and habituation. First-line treatment for bilateral vestibulopathy, vestibular neuritis recovery, and PPPD.

In: Bedside Clinical Tests, Emergency Management, History Taking, Vestibular Neuritis & Labyrinthitis, Paediatric & Elderly, Understanding Symptoms, Vestibular Rehabilitation

A benign tumour arising from the Schwann cells of the vestibular nerve, classically presenting with progressive asymmetric sensorineural hearing loss, tinnitus, and a vague unsteadiness. Vestibular tests show progressive ipsilateral hypofunction. MRI with internal-auditory-meatus protocol is the imaging investigation of choice.

In: Central Causes, Cervicogenic Dizziness, History Taking, Imaging, Pathophysiology, Surgical Management, vHIT

A drug that gives short-term symptomatic relief in acute vertigo by dampening vestibular input to the CNS, without treating the cause. Antihistamines, anticholinergics, benzodiazepines and dopamine antagonists are the main classes; use is normally limited to 3–5 days.

In: Pharmacology

Antihistamines (meclizine, dimenhydrinate), benzodiazepines and anticholinergics that reduce vertigo intensity short-term but delay central adaptation. Use for ≤48 h only.

In: Emergency Management

The Bárány-classified symptoms that qualify for VM: spontaneous, positional, visually-induced or head-motion-induced vertigo, and head-motion-induced dizziness with nausea.

In: Vestibular Migraine

Structured fields in the electronic medical record for HIT/HINTS, DHI, nystagmus characteristics, VOR gain and treatment plan. Free-text notes prevent audit; templates pay back inside six months.

In: Setting Up a Vertigo Clinic

The reflex that stabilises gaze during head movement by driving the eyes in the opposite direction at equal velocity (VOR gain ≈ 1.0). Tested clinically by the head impulse test (bedside) or video head impulse test (instrumented). Reduced gain indicates peripheral vestibular hypofunction.

In: Bedside Clinical Tests, Bilateral Vestibulopathy, Cervicogenic Dizziness, Mal de Débarquement Syndrome, Neuro-Ophthalmology, Paediatric & Elderly, Pathophysiology, Rotational Chair, Understanding Symptoms, Vestibular Rehabilitation

Projections from the vestibular nuclei to brainstem autonomic centres (rostral ventrolateral medulla, nucleus of the solitary tract) that mediate the autonomic accompaniments of vestibular signals — nausea, pallor, sweating, palpitations. Drives the Route 2 cervicogenic presentation, where autonomic features dominate.

In: Cervicogenic Dizziness

The phylogenetically oldest cerebellar zone — the flocculus, nodulus, and parts of the uvula — that calibrates the vestibulo-ocular reflex and processes vestibular afferents. Lesions produce ocular abnormalities (downbeat nystagmus, gaze-evoked nystagmus, periodic alternating nystagmus, impaired smooth pursuit) without prominent limb ataxia.

In: Pathophysiology

Quantitative head impulse test using head-mounted goggles and high-speed video oculography. Validated against scleral search coils (MacDougall 2009).

In: vHIT

Infrared video goggles that abolish visual fixation and record both eyes. The single highest-yield piece of vestibular equipment; first purchase in any setup.

In: Setting Up a Vertigo Clinic

A bedside test measuring the angular VOR by delivering brief unpredictable head impulses while video-tracking the eyes. Reduced gain (<0.8) with corrective saccades on one side indicates ipsilateral peripheral vestibular hypofunction. Should be NORMAL in pure cervicogenic dizziness; an abnormal vHIT mandates investigation for a peripheral cause.

In: Autoimmune Inner Ear Disease, Bedside Clinical Tests, Bilateral Vestibulopathy, Cervicogenic Dizziness, Setting Up a Vertigo Clinic, Emergency Management, Vestibular Neuritis & Labyrinthitis, Neuro-Ophthalmology, Paediatric & Elderly

Infrared-camera recording of eye movements, quantifying nystagmus, saccades, pursuit, and VOR gain. It documents subtle catch-up saccades and adduction lag missed at the bedside.

In: Neuro-Ophthalmology

Goggles-recorded battery comprising gaze, smooth pursuit, saccade, optokinetic, positional and bithermal caloric testing. The diagnostic workhorse of an instrumented vestibular service.

In: Setting Up a Vertigo Clinic

Computer-generated immersive environments that engage vision, hearing and proprioception. In vestibular care VR both provokes (for diagnosis) and retrains (for rehabilitation) balance and gaze.

In: Emerging Technologies

Visual input both drives optokinetic responses and suppresses the VOR; recording in complete darkness isolates the pure vestibular contribution. Achieved with goggles covered or inside a light-tight booth.

In: Rotational Chair

Over-reliance on vision for spatial orientation and balance, so that busy or moving visual scenes provoke symptoms (visual vertigo). A core mechanism and a rehabilitation target in PPPD.

In: History Taking, PPPD

Over-reliance on visual input for balance, often from vestibular deficits, making patients prone to visual vertigo.

In: Understanding Symptoms

A normal subject can suppress > 60 % of nystagmus by fixating during chair rotation. Cerebellar lesions characteristically impair this.

In: Rotational Chair

Dizziness and disorientation triggered specifically by demanding visual surroundings — scrolling screens, patterned floors, traffic — reflecting visual dependence.

In: PPPD, Understanding Symptoms

A self-report measure of dizziness provoked by visual motion; identifies visual dependence and guides visual-desensitisation exercises.

In: Vestibular Rehabilitation

A three-neuron reflex that generates a compensatory eye movement opposite to head rotation, stabilising the visual image on the retina during head motion.

In: vHIT

Gain quantifies the magnitude of the VOR response. In healthy adults at 0.32 Hz it lies between ~0.55 and 0.95. Reduced gain across frequencies suggests bilateral peripheral loss; reduced gain on one side alone suggests unilateral loss not yet compensated.

In: Bilateral Vestibulopathy, Rotational Chair, vHIT

A treatment in which the patient views full-field moving optokinetic stripes while the head is rolled at the perceived rocking frequency, aiming to re-tune the maladapted vestibular adaptation.

In: Mal de Débarquement Syndrome

Lateral medullary infarction, usually from vertebral or PICA disease: vertigo, ipsilateral facial numbness, Horner's syndrome, dysphagia/dysarthria, limb ataxia and contralateral body hypoalgesia, with hearing typically preserved.

In: Central Causes, Subjective Visual Vertical

Bilateral internuclear ophthalmoplegia with primary-position exotropia. Failure of adduction bilaterally on lateral gaze, with abducting nystagmus in the abducting eye. Preserved convergence. Almost pathognomonic for multiple sclerosis in a young patient.

In: Pathophysiology

Thiamine-deficiency triad of confusion, ataxia and ocular signs in at-risk patients. Empirical IV thiamine before glucose; do not wait for confirmation.

In: Emergency Management

A thiamine-deficiency emergency presenting with the classic triad of ophthalmoplegia/nystagmus, ataxia, and confusion. Gaze palsy and gaze-evoked nystagmus reflect involvement of brainstem ocular-motor and vestibular structures; high-dose IV thiamine can reverse it.

In: Bedside Clinical Tests, Neuro-Ophthalmology

A rapid back-and-forth movement of the neck, often from a rear-end collision, that can result in cervicogenic dizziness.

In: Understanding Symptoms

A gaze-stabilisation exercise in which the head moves while the eyes fixate a stationary target, generating retinal slip to drive adaptation.

In: Vestibular Rehabilitation

A harder gaze-stabilisation exercise in which the head and the target move in opposite directions, increasing the sensorimotor demand. Introduced after X1 is mastered.

In: Vestibular Rehabilitation

Therapeutic counterpart to the SHHT: a four-position sequence (sit → supine head-hanging → chin-to-chest → return to sitting), each held ~30 s, that repositions otoconia from the anterior canal back to the utricle.

In: Bedside Clinical Tests