Accepted Manuscript Magnetoencephalography using gradient magnetic field topography (GMFT) can predict successful anterior corpus callosotomy in patients with drop attacks Kota Kagawa, Koji Iida, Akira Hashizume, Masaya Katagiri, Shiro Baba, Kaoru Kurisu, Hiroshi Otsubo PII: DOI: Reference:

S1388-2457(15)00675-6 http://dx.doi.org/10.1016/j.clinph.2015.04.292 CLINPH 2007534

To appear in:

Clinical Neurophysiology

Accepted Date:

24 April 2015

Please cite this article as: Kagawa, K., Iida, K., Hashizume, A., Katagiri, M., Baba, S., Kurisu, K., Otsubo, H., Magnetoencephalography using gradient magnetic field topography (GMFT) can predict successful anterior corpus callosotomy in patients with drop attacks, Clinical Neurophysiology (2015), doi: http://dx.doi.org/10.1016/j.clinph. 2015.04.292

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1 Kagawa et al.

Magnetoencephalography using gradient magnetic field topography (GMFT) can predict successful anterior corpus callosotomy in patients with drop attacks

Kota Kagawaa, b, Koji Iidaa, b, *, Akira Hashizumea, b, Masaya Katagiria, b, Shiro Babac, Kaoru Kurisua, Hiroshi Otsuboc

a

Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan

b

Epilepsy Center, Hiroshima University Hospital, Hiroshima, Japan

c

Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto,

Canada

* Corresponding Author: Department of Neurosurgery, Epilepsy Center, Hiroshima University Hospital 1-2-3 Kasumi Minami-Ku, Hiroshima, 734-8551, Japan

2 Kagawa et al.

HIGHLIGHTS


Gradient magnetic field topography (GMFT) can reveal predominant distributions and spreading patterns of secondary bilateral synchronized generalized spikes in patients with drop attacks.




Good control of drop attacks following anterior corpus callosotomy was correlated with the preoperative higher proportion of anterior bilateral spikes.




In a subset of patients with drop attacks, the anterior 2/3 corpus callosum might be a part of ictogenic pathway of drop attacks.

3 Kagawa et al.

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 (p75% reduction in seizure frequency, severity or both); Class C, moderate improvement (50-75% reduction in seizure frequency, severity, or both); Class D, no significant improvement (