Yes/yes head tremor without appendicular tremor after bilateral cerebellar infarction.

We report a 67-year-old man who developed yes/yes head tremor without appendicular tremor six weeks after right occipital and bilateral cerebellar infarction. The tremor was resting-postural. Its activity increased with excitement, decreased either after ethanol, lateroflexion or rest and stopped at sleep. Four-vessel angiography revealed a well collateralised occlusion of both vertebral arteries. Needle-EMG recordings showed rhythmic, synchronous agonist/antagonist activity in both the splenius capitis and sternocleidomastoideus muscles at a frequency of 2-3 Hz. After administration of botulinum toxin A (DysportR), the tremor markedly improved and vanished completely after a booster. Since then the tremor did not reappear. Delayed-onset, yes/yes head tremor without appendicular tremor may be caused by bilateral cerebellar infarction and can be successfully relieved with botulinum toxin A.