Abstracts

Rationale: Seizure control is known to be the best indicator to determine Tuberous Sclerosis Complex (TSC) patients overall developmental outcome and quality of life. Conventionally, favorable surgical outcome in TSC is associated with concordance between scalp EEG and dominant MRI tuber(s). We studied the usefulness of multimodality imaging tests in identifying surgical candidates and in improving surgical outcome in tuberous sclerosis complex (TSC) patients. Methods: We retrospectively reviewed 21 patients with TSC who underwent resective surgery (8 M/ 13 F, aged 1 - 27 years, mean 7.3) following pre-surgical evaluation. Patients were classified into conventional and challenging candidate groups based on concordance between the dominant tuber on MRI and the ictal onset zone on scalp EEG. Clinical characteristics, type of surgery, surgical outcome and localizing features on non-invasive pre-surgical evaluation including MRI, scalp EEG, SISCOM, SPM analysis of FDG-PET and MEG/MSI were reviewed. Results: Overall seizure-free outcome in 21 patients was 57% (12/21). Out of 21 patients, only ten (48%) were initially classified as conventional candidates following MRI and video scalp EEG. Additional 11 patients were recommended surgery with the help of multi-modality tests. The seizure-free outcome of the challenging candidates (55%, 6/11) was similar to that of the conventional candidates (60%, 6/10). There was no difference in each test s concordance with intracranial EEG: SISCOM 7/12 (58%), SPM-PET 10/19 (53%) and MEG 8/16 (50%). In conventional candidates, seizure-free outcome tended to be higher in the patients whose SISCOM (75%, 3/4), SPM-PET (67%, 4/6) or MEG (100%, 4/4) was concordant with intracranial EEG than the group s average outcome (60%). In challenging group, surgical outcome was tended to be higher in the patients whose SISCOM (67%, 2/3) or SPM-PET (67%, 4/6) showed concordance with ictal EEG than the group s average (55%). Conclusions: Our data suggest that multimodality imaging contributes mainly through expanding surgical candidacy in TSC patients. Large multi-center study may be necessary to see whether multi-modality tests truly contribute to the improved surgical outcome.