Posterior paroxysmal discharge: an aid to early diagnosis in Lafora disease.

Lafora body disease is a rare neurometabolic disorder of autosomal recessive inheritance. Symptoms begin in the second decade with progressive myoclonic epilepsy and survival is unusual beyond the age of 30. We report an electroencephalographic study in four cases of histologically proven Lafora body disease. Posterior epileptiform discharges were found even in the early stages of the disease and may assist in early diagnosis.