Abstracts

Rasmussen encephalitis (RE) is a syndrome of unknown origin which presents with medically refractory focal epilepsy, progressive neurological deficits and cortical atrophy. Anti epileptic medications and immune-modulating agents, provide only transient relief. Hemispherectomy is felt to be the only definitive intervention which halts disease progression and relieves the epilepsy. We studied 1) clinical characteristics of children with RE; 2) seizure outcome after hemispherectomy and 3) factors predictive of good outcome. Histopathology proven cases of RE were reviewed from the pediatric epilepsy surgery database (1979-2005) at our institution. Twelve patients were identified with hemispheric epilepsy (7 left, 5 right) due to RE. All had seizures (onset 3.5 years median age, range 2-11.5 years); and progressive hemiparesis within 4 months (median) of seizure onset. Other neurological deficits included dysphasia (5), cognitive impairment (6) and visual field deficit (2). Ipsilateral interictal, ictal and MRI (atrophy) abnormalities were present in all patients. Additionally, 5/12 had contralateral sharp waves (SWs) on EEG, 2/12 had contralateral EEG seizures and 1 had contralateral MRI signal abnormality prior to surgery. Hemispherectomy was performed 2.8 years (median) after seizure onset. At 2.65 years (median) of follow up, 10/12 (83%) patients were either seizure free (n=8) or had rare seizures only (n=2); 2/12 (17%) continued with frequent seizures. Presence of contralateral SWs did not prevent good outcome (3 seizure free, 2 continued seizures); however both patients with contralateral EEG seizures and the single patient with contralateral MRI abnormality continued to have seizures. RE is a catastrophic epilepsy syndrome and our post operative outcome (83% seizure free or rare seizures only) reiterates the effectiveness of epilepsy surgery in medically refractory cases. Presence of contralateral SWs did not preclude a good outcome, however, presence of contralateral EEG seizures or MRI abnormality prior to surgery may serve as poor prognostic indicator.
Ref (1-5)