Paroxysmal kinesigenic dystonia associated with a medullary lesion

A 67-year-old man experienced the abrupt onset of intermittent spasms of tightening of his throat muscles and elevation of his tongue to the roof of his mouth. These were precipitated by initiating movements, either of his mouth (eating, drinking, speaking, yawning) or of his whole body (arising from bed or a chair, lifting heavy weights). Episodes occurred six to 20 times per day, lasted 10-30 s, then resolved spontaneously. Two years later, results of his general neurological examination, including speech, were normal. Several spasms were provoked by arising from a seated or supine position or by drinking. Objectively, there was a strained dysphonia accompanied by palpable hardening of the supralaryngeal muscles. Each episode resolved within 15 s. Magnetic resonance imaging (MRI) showed evidence of a remote hemorrhage in the medulla. No abnormal blood vessels were seen. Phenytoin 300 mg/day abolished the spasms within days. Decreasing the dose to 200 mg/day months later led to a partial return of symptoms. Relief has persisted for 3 years. This patient has paroxysmal kinesigenic dystonia (PKD) of structures (pharynx, larynx, tongue) innervated by lower cranial motor nerves and a medullary lesion on MRI. PKD has been associated with focal lesions at all levels of the central nervous system (CNS), although never before in the medulla. PKD seems to be a nonspecific phenomenon of the CNS in reaction to injury.