Myoclonic status epilepticus classification

The term myoclonic status epilepticus has been applied to many disparate clinical presentations with a wide range etiologies. Gastaut’s proposed classification system divides myoclonic status epilepticus into “true myoclonic status epilepticus”, which occurs in patients with epilepsy, and “symptomatic myoclonic status epilepticus,” which occurs as a result of another disease process. Because the symptomatic form of myoclonic status epilepticus occurs in patients without epilepsy and may not always be cortical in origin, Gastaut and others have proposed that it should not be considered a subtype of status epilepticus but instead be renamed “status myoclonus.” Alternatively, myoclonic status epilepticus can be classified by its clinical presentation, as the degree of cognitive impairment is the feature that best distinguishes between various etiologies. Note that idiopathic generalized epilepsy is the only condition in which mental status is usually preserved during myoclonic status epilepticus. In myoclonic status epilepticus associated with symptomatic generalized epilepsies and neurodegenerative conditions, particularly progressive myoclonic epilepsies, however, mental status may not be significantly depressed beyond the patient’s baseline (dotted yellow line). (Reproduced with kind permission of Springer Science+Business Media: Gerard E, Hirsch L. Generalised myoclonic status epilepticus. In: Panayiotopoulos CP, editor. The Atlas of Epilepsies. Springer, 2010.)