Abstracts

Rationale: Tuberous sclerosis complex (TSC) is one of the major causes of pediatric intractable epilepsy. Finding epileptogenic zone is challenging. The purpose of this study is to review imaging characteristics of epileptogenic tubers in pediatric TSC patients. Methods: A total of 23 patients (mean age, 5.4 year old) with 581 tubers were retrospectively selected. All patients underwent preoperative multimodality evaluation including MRI, FDG-PET, and Magnetic source imaging. Epileptogenic tuber was defined with presurgical evaluation and result of postsurgical seizure freedom. Imaging of the tuber was divided in three types: type A, B and C and were compared between epileptogenic and non epileptogenic tubers. Type A was defined as isointense on T1 and subtly hyperintense on T2 and fluid-attenuated inversion recovery (FLAIR). Type B was defined as hypointense T1 and homogeneously hyperintense on T2 and FLAIR. Type C was defined as hypointense on T1, hyperintense on T2, and heterogeneous on FLAIR characterized by a hypointense central region surrounded by a hyperintense rim. Results: Among the 37 epileptogenic tubers and 544 non-epileptogenic tubers,284 tubers are located in frontal lobe, 121 in temporal, 115 in parietal, and 61 in occipital lobes. Within the epileptogenic tubers, 14/37 tubers were in frontal lobe and the others were found in the inferior parietal lobes. Within epileptogenic tubers, five wereType A, 23 were type B, and 9 were type C. Type B was most common type of tubers in both epileptogenic and non epileptogenic tubers. There were 13 tubers with calcifications, and 6 of them were epileptogenic. A total of 48 low T2 signal tubers were found and 14 of 48 were epileptogenic. Conclusions: Conventional MRI can suggest epileptogenic tuber characteristics in pediatric TSC Epileptogenic tubers were found most commonly in inferior parietal or frontal lobes and most commonly these were type B tubers.