Treatment and long-term prognosis of myoclonic-astatic epilepsy of early childhood.

PURPOSE

We retrospectively studied patients with myoclonic-astatic epilepsy of early childhood (MAE) to investigate the most effective treatment and long-term seizure and intellectual prognosis.

SUBJECTS

Eighty-one patients with MAE were recruited from among 3600 patients with childhood epilepsy according to the ILAE criteria of MAE.

METHODS

We retrospectively investigated the clinical characteristics and ultimate prognosis of the patients with MAE from the medical records. The effects of various antiepileptic drugs, ketogenic diet and ACTH treatments on myoclonic-astatic seizures (MS/AS), apparently a hallmark of this unique epileptic syndrome, were also studied.

RESULTS

MS/AS in 89 % of the patients disappeared within 1 to 3 years despite initial resistance, but generalized tonic-clonic or clonic seizures [G(T)CS] tended to continue. The most effective treatment for the MS/AS was ketogenic diet, followed by ACTH and ESM. At the last follow-up, 55 patients or 68 % of all the patients had remission of epilepsy, 11 patients or 14 % experienced a recurrence of GTCS after a long remission period but easily regained control, and the remaining 15 patients or 18 % continued to have seizures and intellectual outcomes were poor. In one half of these patients with poor outcomes, repeated minor epileptic status and nocturnal generalized tonic seizures persisted. A family history of epilepsy and a combination of minor epileptic status are risk factors for poor outcomes.

CONCLUSION

MAE is considered to form a clinical spectrum ranging in its main seizure type from myoclonic to atonic, and in seizure and intellectual outcomes from benign to malignant. The overall prognosis, despite initial resistance to treatment, appears to be much better than originally thought when ILAE definitions excluding SME are followed.