Palatal myoclonus is usually due to a brainstem or cerebellar lesion disrupting the dentato-rubro-olivary pathway. Rarely it may be caused by a cortical lesion. The precipitating factor in 70% of all cases is an infarct. We describe an unusual case of a patient with palatal myoclonus who had an old ipsilateral cerebellar infarct and a new contralateral subcortical (corona radiata) infarct. We postulate that the new infarct caused disinhibition of the old cerebellar infarct, resulting in palatal myoclonus. Magnetic resonance imaging (MRI) of the brain did not show any hypertrophy of the inferior olivary nucleus. Her myoclonus proved refractory to clonazepam, valproate and phenytoin.
Palatal myoclonus is a rare movement disorder characterised by rhythmic recurring jerky movements of the soft palate, pharynx, larynx and rarely diaphragm, trunk and limb muscles. It usually develops secondary to brainstem or cerebellar disease (symptomatic palatal myoclonus) interrupting the central tegmental tract or dentato-olivary fibres.
This article is available only as a PDF. Please click on “Download PDF” on top to view the full article.