A rare cause of progressive myoclonic epilepsy: Lafora's disease.

Lafora's disease, a rare progressive myoclonic epilepsy inherited on an aut osomal recessive basis, typically starts in adolescence. The diagnosis rest s on clinical grounds and is confirmed by the demonstration of Lafora bodie s in the brain, skeletal muscle, and/or skin. The disease is caused by a mu tation in a tyrosine phosphatase gene recently mapped to chromosome 6. The case is reported of an 18-year-old Tunisian woman with progressive myocloni c epilepsy. Generalized seizures and myoclonus had first appeared at 14 yea rs of age. Intellectual function had deteriorated slowly and the patient wa s no longer able to attend school. Her parents were consanguineous and five of her cousins had died before the age of 20 years with similar manifestat ions. An electro-encephalogram showed slow background activity with bilater al symmetric discharges of spikes and polyspike-waves. A skin biopsy in the axillary region demonstrated the round or oval PAS-positive inclusions kno wn as Lafora's bodies in the basal region of the apocrine glands. Although Lafora's disease is uncommon, it should be considered in every patient with progressive myoclonic epilepsy, and a skin biopsy should be done at the sl ightest doubt to look fbr Lafora's bodies.