JUVENILE MYOCLONIC EPILEPSY (JME)

Introduction

Juvenile Myoclonic Epilepsy (JME) is a genetically inherited epilepsy syndrome presenting with developmentally normal individuals having a seizure onset in their mid teens.

Signs & Symptoms

Onset

Onset for Juvenile Myoclonic Epilepsy is typically in the early to mid teens. Seizures are aggravated by fatigue, sleep deprivation and ETOH exposure. JME is also though to be praxis induced, with nearly 30% of patients showing a photoparoxysmal response.

Classic Presentation

The classic presentation of Juvenile Myoclonic Epilepsy is with myoclonic seizures shortly after awakening from sleep. These myoclonic events are described as shock-like irregular movements of the arms. In some cases these events may only affect the movement of fingers resulting in the patient appearing clumsy or prone to dropping things.

Alternative Presentations

Juvenile Myoclonic Epilepsy is not restricted to myoclonic seizures despite the name. Absence seizures are seen in addition to myoclonic events in around 1/3rd of patients. Generalized Tonic-Clonic Seizures can also be seen in patients with JME.

EEG

Juvenile Myoclonic Epilepsy patients tend to have a normal background. The hallmark feature of Juvenile Myoclonic Epilepsy is seen in interictal EEG with bursts of 4-6 Hz generalized polyspike and wave. 

Ictal EEG during myoclonic seizures typically will show a single generalized polyspike and wave discharge immediately before clinical movement. Absence seizures show a 3.5-6 Hz generalized spike and slow wave background.

Treatment & Prognosis

Anti-Epileptic Drugs

Valproic Acid has shown to be the most effective drug in the treatment of JME and is typically the first AED used in males and females who are not of childbearing age. Leveteriacetam (Keppra) is approved for thee treatment of myoclonic seizures seen in JME, but it’s effectiveness for treating JME is not well studied. Lamotrigine is widely used in treatment of JME however it has been shown to possibly lead to worsening the myoclonic jerks while proving effective at stopping generalized convulsions and absence seizures.

Lifestyle

Seizure frequency in JME can be highly dependent on sleep deprivation and alcohol consumption. Seizure frequency can be dramatically decreased with counseling for proper sleep and alcohol avoidance.

Prognosis

In individuals with Juvenile Myoclonic Epilepsy, seizures tend to improve around the age of 40 but don’t typically resolve completely. Lifelong AED use is usually necessary and withdrawal often will result in relapse of seizures.