Progressive myoclonic epilepsies.

The progressive myoclonic epilepsies are a rare but extremely debilitating group of disorders that are difficult to diagnose and even harder to treat. They represent a heterogeneous subgroup of those with secondary generalized epilepsy. Efficacy of treatment is often measured in terms of slowing a patient's inevitable decline. Reviewed here are the classification of progressive myoclonic epilepsies, features of myoclonic seizures, the five most prevalent progressive myoclonic epilepsy syndromes-Unverricht-Lundborg disease, myoclonus epilepsy with ragged red fibers (MERRF) mitochondrial disease, Lafora's disease, neuronal ceroid lipofuscinoses, and sialidoses-and current treatment options.