title: Dynamic changes in white and gray matter volume are associated with outcome of surgical treatment in temporal lobe epilepsy.
abstract: BACKGROUND
  The reasons for surgical failure in 30% of patients with unilateral mesial temporal lobe epilepsy (MTLE) are still unclear. We investigated if different outcomes could be associated to different patterns of subtle gray matter atrophy (GMA) and white matter atrophy (WMA), and searched for postoperative magnetic resonance imaging (MRI) changes.
  
  
  METHODS
  We studied 69 controls and 67 operated patients with refractory unilateral MTLE. Patients were grouped as seizure-free (SF) group (34 patients Engel's IA), worthwhile improvement group (23 patients, Engel's IB-IIA) and failure group (10 patients Engel's IIB-IV). We created a voxel-based morphometry/MATLAB code to mask the surgical lacuna, and performed t-test and paired t-test to evaluate preoperative and postoperative MRI scans.
  
  
  RESULTS
  Failure group showed a widespread pattern of preoperative GMA. On SF and improvement groups we identified a more restricted pattern of GMA. The three groups presented a widespread, bilateral pattern of WMA. In contrast, postoperative analyses showed bilateral hemispheric recovery (a relative increase of WM concentration) on SF and improvement groups, but few changes on failure group. We also identified areas with relative postoperative increase of GM on both SF and improvement groups, more widespread on SF group.
  
  
  CONCLUSIONS
  Areas of subtle GMA may be related to poorer surgical outcome. In addition, we demonstrated a postoperative relative increase of WM and GM concentration associated with seizure control. These changes may represent neuroplasticity related to improvement of brain function after seizure control. Further studies with a multimodal approach may help to predict surgical outcome and improve selection of patients for surgical treatment of MTLE.
authors.affiliation: Neuroimaging Laboratory, FCM, University of Campinas, Campinas, SP, Brazil.
authors.forename: Clarissa Lin
authors.initials: CL
authors.lastname: Yasuda
authors.forename: Clarissa
authors.initials: C
authors.lastname: Valise
authors.forename: André Vital
authors.initials: AV
authors.lastname: Saúde
authors.forename: Amanda Régio
authors.initials: AR
authors.lastname: Pereira
authors.forename: Fabrício Ramos
authors.initials: FR
authors.lastname: Pereira
authors.forename: André Luiz
authors.initials: AL
authors.lastname: Ferreira Costa
authors.forename: Márcia Elisabete
authors.initials: ME
authors.lastname: Morita
authors.forename: Luiz Eduardo
authors.initials: LE
authors.lastname: Betting
authors.forename: Gabriela
authors.initials: G
authors.lastname: Castellano
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Mantovani Guerreiro
authors.forename: Helder
authors.initials: H
authors.lastname: Tedeschi
authors.forename: Evandro
authors.initials: E
authors.lastname: de Oliveira
authors.forename: Fernando
authors.initials: F
authors.lastname: Cendes
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D019635:Neurosurgical Procedures; D049268:Positron-Emission Tomography; D011183:Postoperative Complications / Q000473:pathology; D011184:Postoperative Period; D012640:Seizures / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18