Lafora Disease

Progressive myoclonic epilepsies (PMEs) are uncommon genetic disorders of various age groups (infancy, childhood, juvenile, or adult onset) characterized by progressive myoclonus, epileptic seizures and in most cases, dementia and ataxia. Death is the worst possible outcome. Genetic research has led to the identification of many culprit genes, and others are expected to be found. PMEs include Unverricht-Lundborg disease (ULD), Lafora disease (LD), neuronal ceroid lipofuscinoses, sialidosis type I, myoclonus epilepsy and ragged red fibers (MERRF), Gaucher disease type 3, dentatorubral-pallidoluysian atrophy (DRPLA), and other rare forms of PMEs. This article will review Lafora disease, an autosomal recessive PME characterized by intractable myoclonic and photosensitive seizures, drop attacks, ataxia, apraxia, cortical blindness, and rapidly progressive dementia. Its diagnosis requires the presence of the pathognomic Lafora bodies (abnormal glycogen inclusions) in tissue biopsy in addition to the exclusion of other forms of PMEs.