Clinical case · foundation

Acute vertigo with falls on conditions 5 and 6

Vignette

A 42-year-old previously well marketing executive presents to the ENT clinic with five days of constant vertigo, nausea, and oscillopsia, which began suddenly after a flu-like illness. Bedside examination shows right-beating horizontal-torsional spontaneous nystagmus that increases with leftward gaze and is suppressed by visual fixation. Head impulse test shows a positive corrective saccade to the left. Caloric testing shows a 78% unilateral weakness on the left. Audiometry is normal. CDP is performed five days into the illness.

CDP findings

SOT pattern vs normal

MCT — medium-amplitude backward translation

ADT — sway energy across five trials per direction

Audiometric findings

Vestibular neuritis — normal hearing despite acute peripheral vestibular loss.

Vestibular neuritis spares hearing — the inflammation affects the vestibular nerve but not the cochlear nerve. A normal audiogram alongside an acute peripheral CDP pattern (selective C5/C6 reduction with falls) supports the diagnosis. Hearing loss in this context should prompt consideration of labyrinthitis instead.

Single-best-answer

Given the CDP pattern shown alongside the clinical findings, what is the most likely diagnosis?

Teaching point. Park et al. (2017) found that ~70% of acute vestibular neuritis patients show abnormal C5 and/or C6, with frequent falls. The pattern is more severe than chronic compensated loss, reflecting the uncompensated state. The CDP supports — but doesn't make — the diagnosis; HIT and caloric testing are central.