Palatal myoclonus in a patient with a lateral thalamic infarction

Abstract

Palatal myoclonus (PM) is characterized by rhythmic involuntary jerking movement of the soft palate and the pharyngopalatine arch, often involving the diaphragm and laryngeal muscles.1 The two distinct clinical entities, symptomatic PM and essential PM, arise from different pathophysiologic mechanisms.2 Symptomatic PM is usually associated with lesions located in the myoclonic triangle (the Guillain–Mollaret triangle). It consists of the red nucleus, inferior olive, contralateral cerebellar dentate nucleus, and the connecting pathways, namely the central tegmental tract, the inferior cerebellar peduncle, and superior cerebellar peduncle.3 Symptomatic PM may be isolated or more rarely associated with movements of the extremities such as tremor, choreoathetosis, and myoclonus.4,5 A 64-year-old man was referred for acute onset of motor impairment of the right arm. On admission neurologic examination revealed clumsiness of the right arm and right dysmetria on finger-to-nose test. On the fifth day the patient developed myoclonic movements …