Abstract

Acute vestibular syndrome is the rapid onset of vertigo, nausea, and vomiting (with nystagmus, unsteady gait, and head motion intolerance) over seconds-hours, lasting days-weeks. This presumed-viral, peripheral vestibular disorder is known as vestibular neuritis (without auditory symptoms), labyrinthitis (with auditory symptoms), generically acute peripheral vestibulopathy (APV). Most acute vestibular patients have APV, but some have an acute central vestibular syndrome resulting from lesions affecting the pons (the root entry zone of the vestibular nerve, vestibular fascicle, vestibular nucleus), inferior cerebellum (uvula and nodulus), or vestibular cortex (insula). Clinically, it is important to differentiate central vestibular syndrome from APV, because it can produce cerebellar swelling that can lead to brainstem compression and death unless there is neurosurgical intervention. The type of nystagmus evident on examination had been said to differentiate APV from central vestibulopathy, but assessment of nystagmus alone cannot distinguish all cases, and perhaps half of patients with pseudo-vestibular neuritis have unidirectional nystagmus mimicking APV. Therefore, in patients with acute vestibular syndrome, no improvement within 48 hours, abnormal neurological signs, severe headache, profound postural imbalance, unilateral hearing loss, normal head impulse test, and central patterns on vestibular function tests suggest a pseudo-vestibular neuritis.