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Diseases

Genetic and Rare Diseases Information Center (GARD)

Juvenile myoclonic epilepsy


Other Names for this Disease
  • Petit mal, impulsive
  • JME
  • EJM
  • Janz syndrome
  • Myoclonic epilepsy, juvenile, 1
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

I have juvenile myoclonic epilepsy. Does the medication that I take help to cure the condition or just treat the symptoms? Will I need to take medication for the rest of my life? If I have children, will they be affected? Is it safe for me to exercise daily?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is juvenile myoclonic epilepsy?

Juvenile myoclonic epilepsy is an epilepsy syndrome characterized by myoclonic jerks (quick jerks of the arms or legs), generalized tonic-clonic seizures (GTCSs), and sometimes, absence seizures. The seizures of juvenile myoclonic epilepsy often occur when people first awaken in the morning. Seizures can be triggered by lack of sleep, extreme fatigue, stress, or alcohol consumption. Onset typically occurs around adolesence in otherwise healthy children. The exact cause of juvenile myoclonic epilepsy remains unknown, but genetics likely plays a role.[1][2][3] Although patients usually require lifelong treatment with anticonvulsants, their overall prognosis is generally good.[1][2]
Last updated: 3/16/2016

What are the signs and symptoms of juvenile myoclonic epilepsy?

Juvenile myoclonic epilepsy is characterized by myoclonic jerks or seizures, generalized tonic-clonic seizures, and absence seizures. The onset of symptoms occurs at various ages, beginning with absence, which are usually the first to present around 5 and 16 years of age. Myoclonic jerks usually present 1-9 years after initial seizure onset, and generalized tonic-clonic usually appear a few months after onset of myoclonic jerks. In approximately 17% of individuals, myoclonic jerks are the only seizure type.[1][2]

Myoclonic jerks are the hallmark feature of juvenile myoclonic epilepsy. They can be described as quick jerks of the arms and legs. In approximately 20% of individuals, they occur primarily on one side (unilateral). The development of myoclonic jerks usually occurs in clusters. They may precede a tonic-clonic seizure.[2]

Myoclonic status epilepticus is considered to be the most concerning aspect of juvenile myoclonic epilepsy. This occurs when has multiple myoclonic seizures that do not readily stop. It is often precipitated by sleep deprivation or missing medications.[2]
Last updated: 6/30/2016

What causes juvenile myoclonic epilepsy?

The exact cause of juvenile myoclonic epilepsy remains unknown. It is not associated with conditions such as head trauma, brain tumor, or encephalitis. Family history and genetic factors play a strong role in the risk for juvenile myoclonic epilepsy. About one third of affected individuals have a relative with epileptic seizures. Several affected families have been identified as having specific causative mutations in various genes. The pattern of development and inheritance of seizures within these families is often complex.[1]

In individuals with juvenile myoclonic epilepsy, symptoms can be precipitated by:[1][920] 
  • Sleep deprivation
  • Psychological stress
  • Alcohol and drug use
  • Noncompliance of medication
  • Flickering lights such as strobe lights 
  • Menses
  • Time of day - Usually mornings
Last updated: 6/30/2016

How is juvenile myoclonic epilepsy inherited?

Juvenile myoclonic epilepsy is an inherited disorder (about a third of patients with this condition have a positive family history of epilepsy), but the exact mode of inheritance is not clear. Studies have indicated that juvenile myoclonic epilepsy is an autosomal dominant condition (i.e. 50% risk of inheritance). However, it exhibits incomplete penetrance, which means that some individuals who inherit the gene or genes associated with juvenile myoclonic epilepsy do not have symptoms of juvenile myoclonic epilepsy.[1]

Due to the complex nature of inheritance with this condition, one may benefit from consulting with a genetics professional. This type of healthcare provider can provide you with additional information about diagnosis, natural history, treatment, mode of inheritance, and genetic risks to other family members. To find a genetics clinic, we recommend that you contact your primary doctor for a referral. Click here to learn more about genetic consultations and here to find a genetics clinic. 
Last updated: 6/30/2016

How might juvenile myoclonic epilepsy be treated?

Avoidance of precipitating events such as alcohol use and sleep deprivation may be useful but is not sufficient to control the seizures of juvenile myoclonic epilepsy. Medical therapy with anticonvulsants is typically needed and well tolerated. The majority of patients can be well controlled on a single drug, most commonly valproic acid. Other medications that might be utilized separately or in combination include but are not limited to: lamotrigine, levetiracetam, clonazepam, and topiramate.[1][2] 

More details about the medications used to treat juvenile myoclonic epilepsy is available through Medscape Reference and the Epilepsy Foundation
Last updated: 6/30/2016

Do medications taken for juvenile myoclonic epilepsy cure the condition or just treat the symptoms?

Although some childhood epilepsy syndromes tend to go into remission or stop entirely during adolescence, juvenile myoclonic epilepsy is usually present for life once it develops.[4] It can be controlled with medication, but cannot, at this time, be cured.[2] 
Last updated: 1/20/2009

What is the long-term outlook for juvenile myoclonic epilepsy?

Seizures are usually well controlled with seizure medications and studies show that seizures tend to improve after the fourth decade of life. Once an individual is seizures free, seizure medication is typically continued as there is a high risk for recurrence, particularly in individuals with more severe forms. For the majority of individuals, lifelong treatment is necessary.[1][2]
Last updated: 6/30/2016

Is it safe for me to exercise if I am affected by juvenile myoclonic epilepsy?

Research indicates that exercise may benefit individuals with juvenile myoclonic epilepsy. Benefits reported in the medical literature for individuals with epilepsy in general include a decrease in seizure frequency and severity.[5][6][7]

Despite these findings, there are many factors that influence the benefits and risks of exercise in each individual. Therefore, We strongly recommend that you consult your physician with any concerns that you may have regarding the safety of exercise and the effects it might have on your health.
Last updated: 6/30/2016

References
Other Names for this Disease
  • Petit mal, impulsive
  • JME
  • EJM
  • Janz syndrome
  • Myoclonic epilepsy, juvenile, 1
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.