title: Functional MRI connectivity as a predictor of the surgical outcome of epilepsy.
abstract: OBJECTIVE
  In planning epilepsy surgery, it is important to be able to assess the likelihood of success of surgery for each patient so that the possible risk and benefit can be properly considered. In this study, functional connectivity was investigated as a means for predicting surgical outcome from the preoperative functional magnetic resonance imaging (fMRI) of epilepsy patients.
  
  
  METHODS
  Resting-state simultaneous electroencephalography (EEG)-fMRI data were collected from 18 patients with intractable epilepsy before surgery and from 14 healthy subjects. For each patient, EEG-spike correlated fMRI analysis was performed and an activation cluster that overlapped the most with the planned resection area for each patient was chosen as the seed for the functional connectivity analysis. After the functional connectivity maps were computed, laterality indices of functional connectivity were contrasted between patients who had seizures after surgeries (seizure-recurrence group) and those who did not have them for at least a year (seizure-free group).
  
  
  RESULTS
  Patients in the seizure-recurrence group had less-lateralized functional connectivity than patients in the seizure-free group (t(16) = 2.3, after control subtracted and Fisher transformed, p < 0.05, two-tailed).
  
  
  CONCLUSIONS
  This study suggests the potential for using preoperative fMRI connectivity analysis as a predictive outcome measure. If confirmed by further research, a high laterality will be an important addition to the other predictors of better surgical outcome such as febrile seizures, mesial temporal sclerosis, tumors, abnormal MRI, and EEG/MRI concordance.
authors.affiliation: Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520-8043, USA. michiro.negishi@yale.edu
authors.forename: Michiro
authors.initials: M
authors.lastname: Negishi
authors.forename: Roberto
authors.initials: R
authors.lastname: Martuzzi
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Novotny
authors.forename: Dennis D
authors.initials: DD
authors.lastname: Spencer
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000601:surgery; D001931:Brain Mapping; D002648:Child; D004569:Electroencephalography; D004827:Epilepsy / Q000473:pathology* / Q000601:surgery; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013223:Statistics as Topic; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D010100:Oxygen