Midbrain lesions and paroxysmal dysarthria in multiple sclerosis.

We describe three patients with relapsing-remitting multiple sclerosis who presented with paroxysmal dysarthria. In one patient, the symptoms were the only manifestation of an acute relapse. In the other two patients, the attacks appeared during the recovery of a brainstem relapse. All three patients had an acute lower midbrain lesion. The location was central in two patients and left paramedian in the other, and probably involving cerebellothalamocortical pathways. Treatment with carbamazepine was effective.