Glossary

Sudden, continuous vertigo lasting more than 24 hours with nausea, vomiting, spontaneous nystagmus, and an unsteady gait. The key split is benign (vestibular neuritis) versus dangerous (cerebellar or brainstem stroke), resolved at the bedside by HINTS.

The anterior inferior cerebellar artery supplies the inner ear as well as the lateral pons and cerebellum. An AICA infarct can mimic peripheral vertigo because the labyrinth is involved — bedside hearing testing (HINTS Plus) helps unmask it.

A peripheral disorder in which dislodged otoconia enter a semicircular canal, producing brief episodes of vertigo triggered by specific head movements such as lying down or rolling over in bed.

Brief, recurrent, spontaneous episodes of vertigo in young children who are otherwise well between attacks. Considered a migraine precursor and one of the commonest causes of childhood vertigo.

Vertigo arising from the brainstem, cerebellum, or central vestibular pathways. It is typically accompanied by additional neurological deficits such as ataxia, diplopia, or dysarthria, and does not usually affect hearing.

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.

Double vision. During vertigo it is a red flag for central pathology, particularly when combined with other cranial-nerve signs.

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.

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

Distension of the endolymphatic space of the inner ear — the pathological hallmark associated with Ménière's disease, linked to vertigo, fluctuating hearing loss, tinnitus, and aural fullness.

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.

A three-step bedside oculomotor examination used to separate central from peripheral causes of the acute vestibular syndrome. A normal head impulse, direction-changing nystagmus, or a skew deviation each suggest a central cause.

HINTS with the addition of a bedside hearing check. New unilateral hearing loss raises concern for an AICA-territory infarct that can otherwise masquerade as a peripheral lesion.

Inflammation affecting both the cochlear and vestibular parts of the labyrinth, producing acute vertigo together with sensorineural hearing loss and tinnitus — distinguishing it from vestibular neuritis, which spares hearing.

An inner-ear disorder with recurrent attacks of vertigo lasting 20 minutes to several hours, accompanied by fluctuating low-frequency hearing loss, tinnitus, and a sense of aural fullness.

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

Involuntary rhythmic oscillation of the eyes. Its direction, whether it changes with gaze, and whether it suppresses with visual fixation help separate peripheral from central origins.

An illusory to-and-fro movement of the visual scene, classically with head movement or walking. A hallmark of bilateral vestibular hypofunction.

Calcium-carbonate crystals from the utricle. When displaced into a semicircular canal they make it gravity-sensitive, producing the brief positional vertigo of BPPV.

An abnormal communication that allows perilymph to leak from the inner ear, often after barotrauma or straining. Produces pressure- and sound-induced vertigo with fluctuating hearing.

A chronic functional disorder of non-spinning dizziness or unsteadiness lasting more than three months, worse on standing, with movement, and in visually complex environments. Often follows an acute vestibular insult.

Age-related decline in vestibular function, producing chronic imbalance and unsteadiness — typically bilateral, progressive, and without acute vertigo or hearing loss.

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

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

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.

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.

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

Nystagmus occurring without a positional or motion trigger. Its direction and its modulation by visual fixation assist in localising the lesion.

Absence of bone over the superior semicircular canal creates a mobile 'third window', producing sound- and pressure-induced vertigo (the Tullio phenomenon) and autophony.

Vertigo or oscillopsia provoked by loud sound. It signals a third-window lesion such as superior canal dehiscence or perilymph fistula.

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.

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.

A subtype of migraine causing episodic vertigo, sometimes without headache, often with photophobia, phonophobia, and a personal or family history of migraine. A leading cause of episodic vertigo in young to middle-aged adults.

A peripheral disorder caused by inflammation of the vestibular nerve, producing acute, continuous vertigo without hearing loss, usually self-limiting over days as central compensation occurs.

A specialised form of physical therapy that promotes central compensation for vestibular deficits through habituation, adaptation, and substitution exercises.

A benign tumour of the vestibular nerve in the cerebellopontine angle. It typically presents with progressive asymmetric hearing loss and tinnitus, with relatively mild imbalance rather than acute vertigo.

Excessive reliance on visual input for spatial orientation when vestibular or proprioceptive feedback is impaired. Common in PPPD and a driver of visually-induced dizziness.