Myoclonic seizures subside in the fourth decade in juvenile myoclonic epilepsy.

OBJECTIVE: Our aim was to assess the long-term follow-up of juvenile myoclonic epilepsy (JME), with an emphasis on the course of the myoclonic seizures.

METHODS: We enrolled 48 patients with JME (29 F, 19 M; aged 39.9 +/- 9.5 years) followed up for a mean of 19.6 +/- 5.7 years. The remission for 5 years and relapses were evaluated for all seizure types and the changes in severity/frequency of myoclonia were systematically questioned. The clinical and EEG features, antiepileptic drug (AED) treatment regimen, and systemic and psychiatric comorbid diseases were evaluated.

RESULTS: We found a benign course in 66.6% whereas 16.7% had pseudo-resistance due to problems in treatment or lifestyle. The true-resistant course observed in the remaining 16.7% was significantly associated with psychiatric disorders and the presence of thyroid diseases. In 54.2% of the patients, myoclonia were in remission for a mean duration of 8.4 +/- 7.7 years, after an average age of 32.9 +/- 9.6. Of these patients, 6 were on a lower dose of AED in comparison to the dosage needed to control the seizures in the beginning, and 5 patients had stopped AED treatment. None of the latter 11 patients except one relapsed during the follow-up. Furthermore, 21 other patients (43.8%) described substantial alleviation after age 31.3 +/- 8.4 in the severity of myoclonia.

CONCLUSION: Although a great majority of the patients with juvenile myoclonic epilepsy had continuing seizures after a follow-up of 20 years, almost all had either 5-year remission or a substantial alleviation of the myoclonic seizures.