Related Experiment Video
Updated: Jul 17, 2026
Anteromesial Temporal Lobectomy for Medically Intractable Temporal Lobe Epilepsy: An Operative Study
Published on: August 15, 2025
Postoperative recovery of hippocampal contralateral diffusivity in medial temporal lobe epilepsy
Lionel Thivard1, Marie-Laure Tanguy, Claude Adam
1Epileptology Unit, Hôpital de la Salpêtrière, Paris, France. lionel.thivard@psl.ap-hop-paris.fr
Purpose:
To search for a recovery after surgery of mean diffusivity (MD) values in the contralateral nonsclerotic hippocampus of patients with medial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS).
Methods:
Twenty-four MTLE patients (12 right-sided and 12 left-sided MTLE) and 36 healthy volunteers were investigated using diffusion tensor imaging. A region-of-interest approach was used to measure pre- and postoperative interictal hippocampal MD values in patients.
Results:
Diffusion abnormalities in contralateral nonsclerotic hippocampus recovered after surgery (p<0.0001). A subgroup of 14 patients exhibited a clear increase in MD values whereas the remaining 10 patients were stable. No significant difference was found between the two subgroups for each of the electroclinical data studied including early postoperative outcome, all patients being either seizure free or with rare persistent auras.
Conclusions:
This finding suggests that diffusion abnormalities in contralateral hippocampus may represent a functional mechanism linked to the active epileptic process.
Insights
Surgery improved diffusion abnormalities in the non-epileptic hippocampus of medial temporal lobe epilepsy patients. These changes suggest a link between hippocampal diffusion and the active epileptic process.
Area of Science:
- Neuroscience
- Radiology
- Epilepsy Research
Background:
- Medial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS) is a common cause of drug-resistant epilepsy.
- Diffusion tensor imaging (DTI) can detect microstructural changes in the brain.
Purpose of the Study:
- To investigate the recovery of mean diffusivity (MD) values in the contralateral, non-sclerotic hippocampus after epilepsy surgery.
- To determine if diffusion abnormalities in the non-lesional hippocampus resolve post-operatively.
Main Methods:
- Diffusion tensor imaging (DTI) was used to assess 24 MTLE patients and 36 healthy controls.
- Region-of-interest analysis measured pre- and post-operative interictal hippocampal MD values.
Main Results:
- Diffusion abnormalities in the contralateral hippocampus significantly recovered after surgery (p<0.0001).
- 14 patients showed increased MD values, while 10 remained stable; no significant differences were found based on electroclinical data or early outcome.
Conclusions:
- Post-surgical recovery of diffusion abnormalities in the contralateral hippocampus suggests a dynamic functional relationship.
- These findings indicate that contralateral hippocampal diffusion changes may be a functional marker associated with the active epileptic condition.
