Juvenile myoclonic epilepsy
Dieter Janz, MD
Universitätsklinikum Rudolf Virchow, Freie Universität Berlin, Spandauer Damm 130, D-1000 Berlin 19 West Germany
LIKE the first patient known to have infantile spasms,1 the first patient with juvenile myoclonic epilepsy (JME) whose history was well known was a doctor's son. Herpin,2 author of the classical report on this condition, attempted to circumscribe the principal symptom with various terms, such as “impulsions,” “sécousses,” “commotions épileptiques,” without attaching any labels to it (Table1).
Rabot3 later introduced the neutral yet expressive description “myoclonia” into the terminology of epilepsy. In order to prevent confusion with the rare, progressively degenerative myoclonus epilepsy, Lundborg4 in his terminology emphasized the intermittent nature of the jerks. In 1957, Christian and the writer5 described this type of idiopathic epilepsy, characterized by intermittent morning jerks, on the basis of 47 cases as a clinically and clearly definable epileptic syndrome. Almost thirty years later, this syndrome has been rediscovered in the United States and brought to the notice of the English-speaking world by Asconapé and Penry6 and by Delgado-Escueta and Enrile-Bacsal.7 Delgado-Escueta, and before him, Matthes8 honored the writer by naming the syndrome after him.
The cardinal symptom of JME—myoclonic jerks—is a pattern of very short, bilateral, symmetrical and synchronous muscle contractions, affecting mainly the shoulders and arms. They may occur singly or in close succession in clusters of a few jerks at irregular intervals, and they may vary in frequency and intensity. Sometimes they are only perceived inwardly like mild electric shocks, but they may with equal frequency lead to movements so violent that the patient. . .