The role of surface EEG and MRI in the identification of epileptogenic tubers for surgical resection in patients with tuberous sclerosis (TSC) was studied at the Cleveland Clinic, OH. Localized and concordant preoperative MRI and EEG abnormalities were found in 9 of 17 patients (median age 12 years; range 2 months to 31 years), and resection of a localized tuber provided seizure freedom in 8 (89%) patients. Of 8 patients with less well-localized or non-concordant MRI and EEG, only 3 (38%) were seizure free and 5 had persistent seizures following surgery. Overall, 11/17 (65%) patients became seizure free following surgery. The response was not correlated with age at time of surgery or type of surgery (temporal resection vs frontal/multilobar resections). TSC is not a contraindication to epilepsy surgery. [1]

COMMENT. Surface EEG and MRI are effective in localizing epileptogenic tubers for epilepsy surgery in tuberous sclerosis. Patients with concordant EEG and MRI abnormalities have optimal seizure control following surgical resection of the localized tuber. The localization of TSC lesions not showing concordant findings on MRI and EEG requires presurgical testing by surface video-EEG, PET, ictal SPECT, diffusion-weighted MRI, or intraoperative ECoG (Ped Neur Briefs 2004;18:77-78) [2]. In this previous study, resection of tubers and epileptogenic foci localized by the above methods resulted in control of seizures in 78% and reduction of seizure frequency in 20%. Early detection and resection of refractory seizure foci can prevent deterioration of cognitive functioning, improve behavior, and lead to a better quality of life.