Auditory disturbance as a prodrome of anterior inferior cerebellar artery infarction

Objectives: To investigate the clinical and radiological features of patients presenting with an acute auditory syndrome as a prodromal symptom of anterior inferior cerebellar artery (AICA) infarction. Methods: 16 consecutive cases of AICA infarction diagnosed by brain magnetic resonance imaging completed a standardised audiovestibular questionnaire and underwent a neuro-otological evaluation by an experienced neuro-otologist. Results: Five patients (31%) had an acute auditory syndrome as a prodrome of AICA infarction one to 10 days before onset of other brain stem or cerebellar symptoms. Two types of acute auditory syndrome were found: recurrent transient hearing loss with or without tinnitus (n=3), and a single episode of prolonged hearing loss with or without tinnitus (n=2). The episodic symptoms were brief, lasting only minutes. The tinnitus preceding the infarction was identical to the tinnitus experienced at the time of infarction. At the time of infarction, all patients developed hearing loss, tinnitus, vertigo, and ipsilateral hemiataxia. The most commonly affected site was the middle cerebellar peduncle (n=5). Four of the five patients had incomplete hearing loss and all had absence of vestibular function to caloric stimulation on the affected side. Conclusions: Acute auditory syndrome may be a warning sign of impending pontocerebellar infarction in the distribution of the AICA. The acute auditory syndrome preceding an AICA infarct may result from ischaemia of the inner ear or the vestibulocochlear nerve.