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Updated: Jun 21, 2026
Anteromesial Temporal Lobectomy for Medically Intractable Temporal Lobe Epilepsy: An Operative Study
Published on: August 15, 2025
Dynamic changes in white and gray matter volume are associated with outcome of surgical treatment in temporal lobe
Clarissa Lin Yasuda1, Clarissa Valise, André Vital Saúde
1Neuroimaging Laboratory, FCM, University of Campinas, Campinas, SP, Brazil.
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.
Conclusion:
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.
Insights
Subtle gray matter atrophy patterns in epilepsy surgery may predict outcomes. Postoperative increases in white and gray matter indicate successful seizure control and potential neuroplasticity.
Area of Science:
- Neuroimaging
- Epilepsy Surgery
- Neuroplasticity
Background:
- Unilateral mesial temporal lobe epilepsy (MTLE) surgery fails in 30% of patients.
- Reasons for surgical failure in MTLE remain unclear.
- Investigating subtle gray matter atrophy (GMA) and white matter atrophy (WMA) patterns and postoperative MRI changes.
Purpose of the Study:
- To determine if distinct GMA and WMA patterns correlate with surgical outcomes in MTLE.
- To identify postoperative MRI changes associated with seizure control.
Main Methods:
- Studied 67 operated MTLE patients and 69 controls.
- Classified patients into seizure-free, worthwhile improvement, and failure groups.
- Utilized voxel-based morphometry and MATLAB for preoperative/postoperative MRI analysis.
Main Results:
- Widespread preoperative GMA in the failure group; restricted GMA in seizure-free/improvement groups.
- All groups showed widespread, bilateral WMA preoperatively.
- Postoperative MRI revealed bilateral hemispheric WM recovery in seizure-free/improvement groups, but not in the failure group.
- Relative increase in GM concentration observed postoperatively in seizure-free/improvement groups.
Conclusions:
- Subtle GMA patterns may predict poorer surgical outcomes in MTLE.
- Postoperative increases in WM and GM concentration are linked to seizure control.
- Observed changes suggest neuroplasticity contributing to improved brain function post-seizure control.
- Multimodal approaches could enhance prediction of surgical outcomes and patient selection for MTLE treatment.
