The use of the ketogenic diet in a patient with subacute sclerosing panencephalitis.

OBJECTIVE: To report on the effects of the ketogenic diet on a 9-year-old boy with myoclonic jerks due to subacute sclerosing panencephalitis (SSPE). METHODS: A 9-year-old boy presented with progressively worsening myoclonus unresponsive to valproic acid and clonazepam. He was started on the ketogenic diet maintaining urine ketones at greater than 80 mg x dl(-1). RESULTS: Within 2 weeks of dietary initiation, myoclonic jerks stopped. Four weeks later he developed cognitive slowing. Results of electroencephalogram and cerebrospinal fluid analysis were consistent with SSPE. Three months after ketogenic diet initiation, myoclonic jerks reappeared and were refractory to treatment. CONCLUSION: The ketogenic diet may be useful in controlling, even temporarily, the myoclonic jerks of SSPE.