Paroxysmal dyskinesias are rare movement disorders which include paroxysmal kinesigenic choreoathetosis (PKC) and paroxysmal dystonic choreoathetosis (PDC).' PKC presents in the first or second decade of life; the attacks usually last seconds to minutes occurring many times throughout the day and often precipitated by movement. Anticonvulsants such as carbamazepine and phenytoin are successfully used in the treatment of PKC.' PDC is characterized by attacks of dystonia, chorea, andor athetosis lasting minutes to hours and occurring up to three times a day. Presenting as early as infancy, PDC may be precipitated by alcohol or caffeine and typically responds poorly to treatment with anticonvulsants. Both PKC and PDC are typically idiopathic in nature but have been reported secondary to metabolic disturbances and injuries of the nervous A recent report has proposed that paroxysmal dyskinesias be classified as kinesigenic (PKD), nonkinesigenic (PNKD), exertional (PED), or hypnogenic (PHD), with each subtype divided into short-or long-duration events. l o Among secondary causes of paroxysmal dyskinesias, hypocalcemia and hypoparathyroidism have been described,' '-19 and both PKC and PDC have been considered as prominent symptoms. In this report, we describe a boy with pseudohypoparathyroidism and hypocalcemia who presented with a paroxysmal dyskinesia including features common to both PKC and PDC.
Case Report
The patient was a 17-year-old black male who presented to the Pediatric Neurology Clinic at the Children's Hospital of Alabama with a 2-year history of paroxysmal events occurring daily characterized by body stiffening, tremulousness, and an inability to stand. He had been seen 2 months previously for a similar disorder, and valproic acid had been prescribed empirically to treat seizures. An electroencephalogram (EEG) demonstrated nonspecific slowing. His past medical history was remarkable for developmental delay. The boy was in special education classes in school. There was no history of other neurologic disease or head trauma. He had been evaluated for delayed genital development 3 years before his neurology clinic visit but no diagnosis was made.
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