Self-assessment

Why is the head tilted 30° forward at the start of a rotational chair test?

1. To make the patient more comfortable in the chair
2. To bring the horizontal semicircular canals into the plane of rotation
3. To reduce motion sickness
4. To stimulate the otolith organs preferentially

Which structure has a 'baseline' time constant of approximately 4–6 s?

1. The cupula–endolymph system alone
2. The vestibular nuclei
3. The flocculus of the cerebellum
4. The medial longitudinal fasciculus

Which frequencies are typical for a SHA protocol?

1. 1–10 Hz
2. 0.01–0.64 Hz
3. 10–100 Hz
4. ≥ 2 Hz only

A patient shows reduced gain at every SHA frequency and a step-test Tc of 5 s with intact visual suppression. The most likely diagnosis is:

1. Acute unilateral vestibular neuritis
2. Bilateral vestibulopathy
3. Cerebellar lesion
4. Vestibular migraine

Phase lead is increased and asymmetry is high one week after an acute right-sided neuritis. Six months later, SHA looks normal. The best interpretation is:

1. The labyrinth has regenerated
2. Central compensation has restored balanced tonus
3. The caloric test would also be normal
4. There was a measurement error six months later

A patient has a step-test Tc of 35 s, normal gain, and impaired visual suppression of nystagmus. The lesion most likely involves:

1. The lateral semicircular canal
2. The superior vestibular nerve
3. The nodulus/uvula of the cerebellum
4. The medial longitudinal fasciculus

Between attacks of Ménière's disease, the most likely SHA finding is:

1. Bilaterally reduced gain
2. Normal or mildly asymmetric SHA
3. Prolonged Tc and impaired suppression
4. Severe phase lead at every frequency

A SHA frequency returns a spectral purity of 42 %. The correct action is:

1. Accept the value and move on
2. Re-test that frequency after re-alerting the patient
3. Switch immediately to caloric testing
4. Increase peak chair velocity to 200 deg/s

Slow-phase eye velocity during VOR is in which direction relative to chair velocity?

1. Same direction
2. Opposite direction
3. 90° out of phase
4. Random

A 42-year-old with sound-induced vertigo has loud-AC oVEMP amplitudes and a low cVEMP threshold. SHA is normal. The most consistent diagnosis is:

1. Superior canal dehiscence
2. Ménière's disease
3. Bilateral vestibulopathy
4. Vestibular schwannoma

An acute right-sided horizontal nystagmus with reduced right vHIT gain, reduced caloric response on the right, and a normal posterior-canal vHIT. The likely site is:

1. Inferior vestibular nerve
2. Superior vestibular nerve
3. Both divisions
4. Cerebellum

Inter-ictal SHA in vestibular migraine most commonly shows:

1. Markedly reduced gain
2. Mildly *reduced* phase lead at high frequencies
3. Severe directional preponderance
4. Prolonged Tc > 40 s

Which cranial nerve carries vestibular afferent fibres centrally?

1. VII
2. VIII
3. IX
4. X

Which of these patterns most strongly suggests a central rather than peripheral lesion?

1. Reduced gain with high phase lead
2. Normal gain with very long Tc and failed visual suppression
3. Asymmetry with normal Tc
4. Mild low-frequency gain reduction

Why might a vestibular schwannoma sometimes produce only mild RCT findings despite a large tumour?

1. RCT does not test the vestibular nerve
2. Slow tumour growth allows time for central compensation
3. Schwannomas only damage the cochlear nerve
4. Caloric testing is more sensitive than RCT

Per the 2017 Bárány criteria, a SHA-based diagnosis of bilateral vestibulopathy requires a gain below which threshold across frequencies?

1. < 0.6
2. < 0.4
3. ≈ < 0.1–0.2 at 0.1 Hz with phase lead > 68°
4. < 0.05

Vision is denied during SHA recording chiefly because:

1. It prevents motion sickness
2. Visual targets activate optokinetic drive and suppress the VOR
3. Eye-tracking cameras need darkness to work
4. It reduces electrical interference

The earliest age-related RCT change is typically:

1. Reduced gain at 0.01–0.04 Hz
2. Prolonged Tc
3. Increased asymmetry
4. Increased visual suppression

What does the rotational chair test offer that the caloric test does not?

1. Side localisation
2. Multi-frequency, bilateral, simultaneous stimulus
3. Higher cost
4. Stimulation of the otoliths

VOR gain at 0.32 Hz in a healthy adult is typically:

1. 0.1–0.3
2. 0.55–0.95
3. 1.2–1.5
4. Negative

Six months after a left labyrinthectomy a patient's SHA is symmetric and within normal limits, but the caloric test still shows a 90 % left weakness. The best explanation is:

1. Caloric test is faulty
2. Central compensation normalises SHA while leaving caloric weakness
3. The labyrinth has regenerated
4. Patient had a contralateral injury

Which nucleus is the principal site of the velocity-storage integrator?

1. Lateral vestibular nucleus
2. Medial and superior vestibular nuclei
3. Inferior vestibular nucleus
4. Dentate nucleus

Which of the following best distinguishes uncompensated unilateral peripheral loss from a central lesion on RCT?

1. Reduced gain
2. Asymmetry with elevated phase lead and *normal* visual suppression
3. Normal Tc
4. Spectral purity > 80 %

Why does the step-velocity test use both an acceleration and a deceleration phase?

1. To check chair calibration
2. Acceleration excites one ear's canal; deceleration tests the other
3. Patient comfort
4. To stimulate the otoliths