Epilepsy surgery for postinfectious lesions: A review

Abstract

Cerebral infections are a common cause of structural focal epilepsy, particularly in developing countries, where the risk of unprovoked seizures is higher and is related to brain lesions and status epilepticus during the acute phase. Despite the prevalence of pharmacoresistant epilepsy after cerebral infections, few patients are referred for epilepsy surgery. However, those with mesial temporal sclerosis (MTS), particularly linked to meningitis or encephalitis in early life, are excellent surgical candidates. Encephalitis before age four is associated with MTS, indicating a period of hippocampal vulnerability. Temporal resections are the most common procedures in these patients. In contrast, extratemporal resections are less common and generally less successful, especially in patients with multifocal epilepsy or parasitic infections. Patients with severe hemispheric damage from infections and contralateral hemiparesis may undergo hemispheric procedures, with overall favorable outcomes. Surgery for post-viral encephalitis, such as herpes simplex virus encephalitis, is often less effective due to widespread brain involvement, though younger patients with unilateral hippocampal atrophy fare better. Although neurocysticercosis is a leading cause of epilepsy in endemic regions, surgery is rarely performed. However, resecting MTS along with calcified lesions can improve seizure control in pharmacoresistant cases. This review emphasizes the importance of surgery for appropriately selected patients with postinfectious epilepsy.

Keywords: Encephalitis; Epilepsy surgery; Hemispherotomy; Hippocampal sclerosis; Meningitis; Refractory epilepsy.