[Evoked acoustic responses in the brain stem of subjects with facial hemispasm and megabasilar anomaly].

We examined 8 subjects affected by hemifacial spasm. The CT exam showed a megadolichobasilaris vessel in five of them. Four of these five presented BAEP anomalies. Three of these four showed a decreased amplitude of the V wave and the other one a pathological increment of the I-V interval.