[Unilateral palatal myoclonus with peculiar ocular movements--neurotological studies and MRI].

This is the first report of unilateral palatal myoclonus with which two different ocular movements were synchronized. A 55-year-old woman was admitted to our hospital due to intubation and dysarthria of sudden onset after three similar attacks for these four years. On admission right ptosis, hypalgesia in the right face, right facial nerve palsy, dysarthria, bilaterally increased deep tendon reflexes and trunkal ataxia were noted. Continuous repetitive contractions at 110/min frequencies were observed in the left soft palate, pharynx and larynx. On electronystagmography and electro-magnetic search coil system (Skala system), two different ocular movements, i.e., rotary oscillation with torsion and nystagmus to the right, successively alternated each other at random during eyelids closure. They were synchronized with palatal myoclonus. True nystagmus synchronized with palatal myoclonus has not been reported. When she calculated, rotary oscillation disappeared. In sleep polygraphy, rotary oscillation reduced in amplitude in stage 1 and disappeared in stages 2, 3, 4 and REM. On the other hand, the nystagmus reduced in amplitude in stage 1 and 2 and disappeared in stages 3, 4 and REM. The direction of nystagmus was converted to the left in stages 1 and 2. Similarly, in a drowsy state induced by intravenous injection of 7 mg diazepam, the direction of the nystagmus was converted to the left. On brain magnetic resonance imaging (MRI) right inferior olive was identified as a well circumscribed, enlarged increased signal area on T2-weighted and proton density-weighted images in addition to the lesions of infarcts in left corona radiata, posterior limb of right internal capsule and tegmentum pontis.(ABSTRACT TRUNCATED AT 250 WORDS)