What is it like?

Here's a typical story: I have always had these little jerks of my arms, ever since I was 12 or 13 years old, but I assumed everybody had them. They never really bothered me until one day I had a big one and fell down. I had a couple of grand mal seizures and was put on medication for a few years. Because I didn't have any more seizures, the drugs were stopped. But during college, whenever I stayed up all night or drank too much, the next day I would get lots of those jerks, and sometimes a big seizure right after the jerks. I never thought much about those jerks; in fact, my wife, who doesn't have epilepsy, gets them sometimes as she is falling asleep.

People with JME have myoclonic seizures (quick little jerks of the arms, shoulder, or occasionally the legs), usually in the early morning, soon after awakening. The myoclonic jerks sometimes are followed by a tonic-clonic seizure. Absence seizures also may occur.

Who gets it?

Juvenile myoclonic epilepsy (JME) is one of the most common epilepsy syndromes. It accounts for 7% of all cases of epilepsy. The seizures of JME may begin between late childhood and early adulthood, usually around the time of puberty. Fifteen percent of children with childhood absence epilepsy later develop JME. It also is more likely in people who have family members with generalized epilepsy. The intellectual ability of people with JME is the same as that of people in general.

Tell me more

Some people with JME experience seizures that are triggered by flickering light, such as strobe lights at dances, TV, video games, or light shining through trees or reflecting off ocean waves or snow. These are called photosensitive seizures. Occasionally, myoclonic seizures are also provoked by factors such as decision-making or calculations.

The EEG usually shows a pattern of spikes and waves, which often appears in response to flashing lights. An EEG performed during sleep and continuing for a short time after awakening is the best way to confirm the diagnosis. CT and MRI scans of the brain are normal and are seldom necessary.

JME often has a genetic basis. In some families, genes associated with an increased risk of JME have been identified on chromosomes 6, 8, or 15. Nevertheless, the large majority of children in these families do not develop epilepsy.

How is it treated?

The seizures of more than 80% of people with JME are well controlled with medication. Depakote (valproate) is usually used. It works for each of the three types of seizures that can be seen with JME