What causes JME to be drug-resistant?
Juvenile myoclonic epilepsy (JME) is not considered a severe condition. If the seizures are not controlled by medication, the doctor may have doubts about the diagnosis, the adequacy of treatment, or about the patient's lifestyle or compliance with the medication regimen. True resistance to the usual medications does happen, however.
JME is a generalized epilepsy. Myoclonic jerks are the hallmark of the syndromethey should occur at some time in 100% of people with JME. In addition, generalized tonic-clonic seizures are found in 80%, and absence seizures in 25%.
Patients with JME often find that seizures are triggered by lifestyle factors or external events:
- flashing lights (affecting 25-40%)
- sleep deprivation
- fatigue
- alcohol intake
- stress
What are the risk factors for poor seizure control?
Little is known about the prevalence and risk factors for drug resistance or intractability in JME. Few studies mention the features associated with poor seizure control.
Dasheiff and Ritaccio reported on 12 patients with intractable JME. These patients had epilepsy for an average of 21 years, during which diagnosis and appropriate treatment were delayed. Many of these patients had EEG patterns that were not typical of JME.
Gelisse and colleagues followed 155 patients with JME and found that about 15% could be considered drug-resistant. Another 10% continued to have seizures because of failure to take medication as prescribed, too low a prescribed dosage, or a lifestyle that included too many seizure triggers.
None of the patients with drug-resistant JME in Gelisse's study had only myoclonic jerks or the combination of absence seizures and myoclonic jerks. Instead, 63% of these patients had all three types of seizures. Psychiatric disorders were found in nearly 60% of the patients with poorly controlled seizures but in less than 20% of patients with well controlled seizures. Personality disorders (especially borderline personality responsible for social maladjustment) were the most frequent type of psychiatric problems found, affecting 25% of resistant cases and 10% of nonresistant ones.
Does control change over time?
JME almost always requires lifelong treatment. The frequency of seizures may fluctuate, however. Some patients with a less severe form may have short periods of worsening. Others, whose seizures are more difficult to treat, may later experience spontaneous improvement in seizure control.
For example, one patient experienced his first seizure at age 16. He was started on Depakote and stopped having seizures. But when he was 27, his epilepsy became active again and did not respond to several medications, with no apparent explanation.
Further study is necessary to identify the clinical significance of seizure recurrence in JME.
Find out more
Here are links to two articles on this topic:
Dasheiff RM, Ritaccio AL. Characterization of intractable juvenile myoclonic epilepsy: new perspectives on primarily generalized seizures. Seizure 1993 Mar;2(1):11-9.
A study of 12 patients with intractable juvenile myoclonic epilepsy lasting for many years.
Gelisse P, Genton P, Thomas P, Rey M, Samuelian JC, Dravet C. Clinical factors of drug resistance in juvenile myoclonic epilepsy. J Neurol Neurosurg Psychiatry 2001 Feb;70(2):240-3.
A study from France of 155 newly diagnosed JME patients followed for an average of 13.5 years in the 1980s and 1990s. A significant subgroup presented difficult therapeutic problems.
Find more information at PubMed, a service of the National Library of Medicine.