title: The correlation between ictal semiology and magnetoencephalographic localization in frontal lobe epilepsy.
abstract: OBJECTIVE
  The aim of this study was to investigate the correlation of ictal semiology with localization and/or lateralization by magnetoencephalography (MEG).
  
  
  METHODS
  Seven patients from the Neurology Department of the University Hospital Erlangen who underwent resective surgery for frontal lobe epilepsy (FLE) with an Engel 1a outcome were investigated retrospectively. MEG localizations were classified according to five compartments (separate or combined) of the frontal lobe: frontal basal (FB), frontal lateral (FL), frontal polar (FP), frontal mesial (FM), and frontal precentral (FPr). On the basis of previous studies that investigated the value of ictal semiology in localization and lateralization, we compared the experiential localization and/or lateralization of the epileptogenic region deduced from ictal semiology, that is, both seizure history and ictal video/EEG monitoring, with MEG localization.
  
  
  RESULTS
  It is easier to determine lateralization than localization from ictal semiology because of the variety of signs and fast propagation in FLE. All of the patients had specific MEG localizations according to favorable postoperative outcome. Three patients had MEG foci associated with ictal semiology; in another four, the MEG localization was adjacent to the estimated area suggested by ictal semiology. Head version signs could be observed in all compartments of the frontal lobe: clonic in FB and FP areas; postural in FPr, FL, and FM areas; hypermotor in FB, FP, FPr, and FM areas; sensation aura in FB, FL, and FM areas; and automatisms in FP, FPr, and FL areas. All patients had concordant lateralizing and limited valuable locating information from ictal semiology, but no complete correlation with MEG foci.
  
  
  CONCLUSIONS
  Ictal semiology may indicate the involvement of a symptomatogenic brain region during a seizure, but extent of seizure onset in central motor or sensorimotor area is not reliable enough to indicate the seizure onset zone and favorable postoperative outcome in FLE. MEG provided specific localization of epileptic activity in a FLE compartment, and indicated the relationship between epileptogenic region and lesion. MEG can complement ictal semiology in establishing a noninvasive focal localization hypothesis.
authors: Neurological Clinic, University Hospital Erlangen, Erlangen, Germany.
authors: Xintong
authors: X
authors: Wu
authors: Stefan
authors: S
authors: Rampp
authors: Daniel
authors: D
authors: Weigel
authors: Burkhard
authors: B
authors: Kasper
authors: Dong
authors: D
authors: Zhou
authors: Hermann
authors: H
authors: Stefan
mesh_terms: D000328:Adult; D004569:Electroencephalography; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D015225:Magnetoencephalography; D008297:Male; D012189:Retrospective Studies; D013223:Statistics as Topic; D055815:Young Adult