Palatal myoclonus and denervation supersensitivity in the central nervous system.

We postulate that palatal myoclonus after infarction of the brainstem or cerebellum, or both, is the manifestation of denervation supersensitivity secondary to lesions involving the dentatorubroolivary system. Two cases of our own and 31 from the English and French literature were analyzed in order to determine the delay between the occurrence of presumed anatomical lesions and the recognition of palatal myoclonus. The intervals varied from 2 to 49 months with the median between 10 and 11 months. The natural history of palatal myoclonus following brainstem infarction seemed consistent with the hypothesis.