1/2. Sudden deafness and anterior inferior cerebellar artery infarction.BACKGROUND AND PURPOSE: Acute ischemic stroke in the distribution of the anterior inferior cerebellar artery (AICA) is known to be associated with vertigo, nystagmus, facial weakness, and gait ataxia. Few reports have carefully examined the deafness associated with the AICA infarction. Furthermore, previous neurological reports have not emphasized the inner ear as a localization of sudden deafness. The aim of this study was to investigate the incidence of deafness associated with the AICA infarction and the sites predominantly involved in deafness. methods: Over 2 years, we prospectively identified 12 consecutive patients with unilateral AICA infarction diagnosed by brain MRI. Pure-tone audiogram, speech discrimination testing, stapedial reflex testing, and auditory brainstem response were performed to localize the site of lesion in the auditory pathways. electronystagmography was also performed to evaluate the function of the vestibular system. RESULTS: The most common affected site on brain MRI was the middle cerebellar peduncle (n=11). Four patients had vertigo and/or acute auditory symptoms such as hearing loss or tinnitus as an isolated manifestation from 1 day to 2 months before infarction. Audiological testings confirmed sensorineural hearing loss in 11 patients (92%), predominantly cochlear in 6 patients, retrocochlear in 1 patient, and combined on the affected side cochlear and retrocochlear in 4 patients. electronystagmography demonstrated no response to caloric stimulation in 10 patients (83%). CONCLUSIONS: In our series, sudden deafness was an important sign for the diagnosis of AICA infarction. Audiological examinations suggest that sudden deafness in AICA infarction is usually due to dysfunction of the cochlea resulting from ischemia to the inner ear.- - - - - - - - - - ranking = 1keywords = caloric (Clic here for more details about this article) |
2/2. 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.- - - - - - - - - - ranking = 1keywords = caloric (Clic here for more details about this article) |