title: Magnetoencephalography using gradient magnetic field topography (GMFT) can predict successful anterior corpus callosotomy in patients with drop attacks.
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).
  
  
  CONCLUSIONS
  GMFT is valuable to evaluate pre- and post-operative predominant spikes in patients with drop attacks.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan; Epilepsy Center, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Kagawa
authors.affiliation: Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan; Epilepsy Center, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Iida
authors.affiliation: Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan; Epilepsy Center, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Hashizume
authors.affiliation: Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan; Epilepsy Center, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Katagiri
authors.affiliation: Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Shiro
authors.initials: S
authors.lastname: Baba
authors.affiliation: Department of Neurosurgery, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kurisu
authors.affiliation: Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Otsubo
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003337:Corpus Callosum / Q000503:physiopathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D060526:Magnetic Fields; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D013575:Syncope / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D055815:Young Adult
keywords: Anterior/posterior spikes; Drop attack; Generalized spikes; Secondary bilateral synchrony; Spreading pattern