Kota Kagawa1, Koji Iida1, Akira Hashizume1, Masaya Katagiri1, Shiro Baba2, Kaoru Kurisu3, Hiroshi Otsubo2. 1. Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan; Epilepsy Center, Hiroshima University Hospital, Hiroshima, Japan. 2. Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Canada. 3. Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan.
Abstract
OBJECTIVE: Gradient magnetic field topography (GMFT) with magnetoencephalography (MEG) has been developed to demonstrate magnetic-field gradients of epileptic spikes on a volume-rendered brain surface. We evaluated GMFT in patients with anterior 2/3 corpus callosotomy (ACC) for drop-attacks. METHODS: Eight patients (age; 11-37 years) underwent ACC. GMFT evaluated the predominant distributions (anterior/posterior) and the spreading patterns (unilateral/bilateral) of pre- and postoperative interictal MEG spikes corresponding to generalized spikes on EEG. We compared the occurrence of four types of spikes; anterior unilateral spike (AUS), posterior unilateral spike (PUS), anterior bilateral spike (ABS), posterior bilateral spike (PBS) between 5 patients (group G) with good control of drop attacks and 3 patients (group P) with residual drop attacks. RESULTS: Preoperatively, GMFT showed the proportion of ABS in group G (mean ± SD, 57.4 ± 9.7%) was significantly (p=0.024) higher than that in group P (31.6 ± 15.2%). The number and proportion of postoperative ABS and PBS in group G were significantly decreased (p<0.05 in all). CONCLUSION: GMFT is valuable to evaluate pre- and post-operative predominant spikes in patients with drop attacks. SIGNIFICANCE: GMFT revealed a higher proportion of preoperative ABS and postoperative decline of both ABS and PBS in patients with good control of drop attacks after ACC.
OBJECTIVE: Gradient magnetic field topography (GMFT) with magnetoencephalography (MEG) has been developed to demonstrate magnetic-field gradients of epileptic spikes on a volume-rendered brain surface. We evaluated GMFT in patients with anterior 2/3 corpus callosotomy (ACC) for drop-attacks. METHODS: Eight patients (age; 11-37 years) underwent ACC. GMFT evaluated the predominant distributions (anterior/posterior) and the spreading patterns (unilateral/bilateral) of pre- and postoperative interictal MEG spikes corresponding to generalized spikes on EEG. We compared the occurrence of four types of spikes; anterior unilateral spike (AUS), posterior unilateral spike (PUS), anterior bilateral spike (ABS), posterior bilateral spike (PBS) between 5 patients (group G) with good control of drop attacks and 3 patients (group P) with residual drop attacks. RESULTS: Preoperatively, GMFT showed the proportion of ABS in group G (mean ± SD, 57.4 ± 9.7%) was significantly (p=0.024) higher than that in group P (31.6 ± 15.2%). The number and proportion of postoperative ABS and PBS in group G were significantly decreased (p<0.05 in all). CONCLUSION: GMFT is valuable to evaluate pre- and post-operative predominant spikes in patients with drop attacks. SIGNIFICANCE: GMFT revealed a higher proportion of preoperative ABS and postoperative decline of both ABS and PBS in patients with good control of drop attacks after ACC.