The diagnosis of Lafora's syndrome, progressive myoclonus epilepsy and intracytoplasmic periodic acid-Schiff-positive inclusions (Lafora bodies), was made by skin biopsy in a 16-year-old girl at the Depts of Pathology and Dermatology, University of Texas Medical Branch, Galveston, TX. She presented because of refractory generalized convulsions. In good health until 8 months previously, she developed progressive incoordination, slurred speech, weakness, and impaired school performance followed after 2 months by her first generalized tonic-clonic seizure and progressive mental deterioration. The family history was negative. Metabolic, endocrine, and infectious disorders were excluded. CT scan was normal. EEG showed “generalized cerebral dysfunction.” Round to oval, intracytoplasmic inclusions, strongly PAS-positive, in eccrine duct cells and peripheral nerve bundles of dermis were demonstrated histologically in cryostat- and paraffin-embedded sections and by electronmicroscopy. Skin biopsy, the least invasive method of identifying the Lafora body, was first proposed by . A summary of other disorders and their characteristic inclusions that may be diagnosed by skin biopsy includes neuronal ceroid lipofuscinoses (Bielschowski and Spielmeyer-Vogt), glycogenosis II (Pompe's), metachromatic leukodystrophy and occasionally, globoid leukodystrophy (Krabbe). 
COMMENT. A number of syndromes of progressive myoclonus epilepsy, frequently autosomal recessive in inheritance, have been described. The Lafora type is characterized by a rapidly progressive dementia, myoclonus, and intracytoplasmic Lafora body inclusions demonstrated in neurons, especially localized in the substantia nigra and dentate nucleus, in the heart, liver, muscle, retina, nerves and now in skin. The EEG shows discharges of fast spike-waves and polyspike-waves, photosensitivity, deterioration of background activity, and multifocal abnormalities especially posteriorly. The onset occurs between 6 and 19 years of age and the patient dies within an average of 5.5 years after onset. No enzymatic defect has yet been identified.
The Unverricht-Lundborg types have a slower rate of progression than the Lafora myoclonic epilepsy, with onset at about age 10 years, variable severity of myoclonus, associated cerebellar ataxia, and milder mental symptoms, patients surviving for 15 years and more. This variety known as the Finnish or “Baltic” myoclonus epilepsy in which Lafora bodies are absent was exacerbated by phenytoin and benefitted by sodium valproate.