The diagnosis, treatment, and outcomes of seven children with a syndrome termed “malignant rolandic-sylvian epilepsy (MRSE)” are described following retrospective chart analyses of 24 patients who were studied with magnetoencephalography (MEG) and intracranial video-EEG (IVEEG) at The Hospital for Sick Children, Toronto, Canada. All had undergone surgical treatment for intractable localization-related epilepsy between 1997 and 2000. The seven children diagnosed with MRSE, ages 6-16 years, had common characteristics: refractory sensorimotor seizures (SMS), frequent frontocentrotemporal EEG spikes, normal MRI, rolandic-sylvian spike source on MEG, and cognitive deficits. Seizures had begun between 1 and 6 years of age, and were refractory to antiepileptic medications for more than 5 years. Subdural ECoG was required to lateralize and localize the epileptic zone before surgery. Cortical excision and multiple subpial transection controlled seizures completely in 3 and almost fully in 4, at 30 months’ mean follow-up. Two had a worsening of attentional deficits. Analysis of excised tissue showed neuronal migration disorder in 3 and gliosis in 2. 
COMMENT. The term malignant rolandic-sylvian epilepsy (MRSE) has been coined for a subgroup of patients with atypical benign rolandic epilepsy (BRE) and Landau-Kleffner syndrome (LKS) variant, and others with intractable sensorimotor seizures, EEG centrotemporal spikes, and cognitive impairment. MRSE differs from BRE and LKS in seizures that are refractory, secondarily generalized, and occurring in clusters. Intracranial video-EEG, neuropsychological testing, and MEG are important in diagnosis and surgical evaluation and treatment.