Abstracts

Myoclonic astatic epilepsy (MAE) is an idiopathic generalized epilepsy syndrome characterized by myoclonic (MS), astatic (AS), and myoclonic-astatic (MAS) seizures. Treatment resistance is common, and may affect neurodevelopmental outcome. Little information exists on the use of the newer antiepileptic treatments (AET) in MAE. We reviewed treatment practices at our institution to understand which AET were effective. We reviewed the charts of all patients with MAE treated at our institution between 1998 and 2005. We describe the clinical characteristics of these children and their responses to antiepileptic therapies. Twenty patients met criteria for MAE (16 boys). Mean follow-up was 52 months (range 25-86) in 15 patients, and 4 months (range 2-6) in 3 patients. Two had a single visit. Patients frequently had a family history of epilepsy (45%) or of febrile seizures (35%). Mean age of first seizure was 37 months (range 12-64 months). Presenting seizure type was MS, AS, or MAS (n=4), GTC (n=14), or febrile GTC (n=4). All children had daily MS, AS, or MAS. Fifteen also had generalized tonic-clonic seizures (GTC) and 11 had absence seizures. Half of initial EEGs had abnormal backgrounds and/or interictal epileptiform discharges. During the active seizure period, 66% had background slowing and 94% had spike-wave or poly-spike wave discharges. After seizures were controlled, background abnormalities persisted in 20% and interictal epileptiform discharges persisted in 60%. Fourteen of 18 patients became seizure free a median of 17 months after seizure onset (range 5-36 months). The mean number of AET used was 5 (range 1-9). Cessation of seizures occurred with the ketogenic diet (KD, n=5), topiramate (TPM, n=3), lamotrigine (LTG, n=2), and levetiracetam (LEV, n=1). While valproate (VPA) was used in 16 patients, and was the first drug chosen after MAE diagnosis in ten patients, it halted seizures in only one. Two had remissions not attributable to medication changes. TPM was used in 12 patients, LTG in 11, and LEV in 7. KD was the most likely to induce remission (5 of 9) and was used after failure of multiple AET (mean=6). Seizures returned 3-4 years after initial remission in 3 patients, but were infrequent or easily treated. At last visit, 6 children were developmentally normal, 11 had mild behavioral or developmental abnormalities, and 1 was moderately delayed. Demographic features and outcomes of our patients were consistent with other series. Persistent epileptiform discharges on EEG were common, even after seizure remission. Valproate was the most often used first medication for MAE but was rarely effective. Newer AET such as TPM, LTG, and LEV have some efficacy. KD was effective in many patients but was frequently offered late in the treatment course. We recommend consideration of KD sooner in the treatment of patients with MAE.