[Brain-stem auditory evoked potentials (BAEPs) and computerized tomography (CT scans) in patients with reversible...

BAEPs recordings and brain CT Scans have been conducted in 11 patients with RIAs of the vertebral-basilar system. Five patients presented recurrent transient ischemic attacks (TIAs) completely clearing in 24 h, while in the other patients a full recovery took place over a longer period, within 3 week (RINDs). Each patient underwent BAEPs recording, as well CT Scans, EEG and oto-neurological examination, 7-20 days after the last RIA, when all signs and symptoms had disappeared. Both ears were subsequently stimulated and bipolar EEG activity was recorded from Cz and the mastoid electrode ipsilateral to stimulation. At least two sets of 1500 averaged responses from each ear were added. The I-III, III-V, I-V interpeak latencies (IPLs) as well as the IV-V/I amplitude ratio were measured and compared with the values obtained in a control group. Increased IPLs were detected in 4 cases of the TIA group and in 2 of the RIND group. Amplitude ratio was always normal. Any positive information provided by CT Scan showed cerebral atrophy in 4 patients with TIAs and in 1 patient with RIND. BAEPs recording is a relatively simple, non-invasive neurophysiologic test, which can give objective evidence for brainstem dysfunction in vertebro-basilar RIAs.