Paroxysmal dysarthria and ataxia in multiple sclerosis and corresponding magnetic resonance imaging findings.

Paroxysmal dysarthria (PD) and paroxysmal dysarthria-ataxia (PDA) syndromes are uncommon symptoms of the neurological dysfunction in multiple sclerosis (MS). We describe two patients who had clinically definite MS presented with symptomatic PD and PDA syndromes, respectively, related to demyelinating lesions. In one patient, the PD symptom was the initial manifestation of an acute episode. In the other patient, the episode of dysarthria was accompanied by ataxia disorders. Both patients had midbrain lesions at or below the level of the right red nucleus on magnetic resonance imaging (MRI), confirming that this area is critically involved. Both responded well to carbamazepine (CBZ).