Dynamic changes in white and gray matter volume are associated with outcome of surgical treatment in temporal lobe epilepsy.
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.
Yasuda
Clarissa Lin
CL
Neuroimaging Laboratory, FCM, University of Campinas, Campinas, SP, Brazil.
Valise
Clarissa
C
Saúde
André Vital
AV
Pereira
Amanda Régio
AR
Pereira
Fabrício Ramos
FR
Ferreira Costa
André Luiz
AL
Morita
Márcia Elisabete
ME
Betting
Luiz Eduardo
LE
Castellano
Gabriela
G
Mantovani Guerreiro
Carlos Alberto
CA
Tedeschi
Helder
H
de Oliveira
Evandro
E
Cendes
Fernando
F
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
D019788:Fluorodeoxyglucose F18