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Updated: May 26, 2025
Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury
Published on: November 19, 2012
Multiple Hippocampal Transections: Initial Clinical Experience with Modified Technique
Jan Šroubek1, Lenka Krámská2, Michaela Nová3
1Department of Neurosurgery, Na Homolce Hospital, Prague, Czech Republic; Department of Neurosurgery, Faculty of Medicine, Charles University, Hradec Kralove, Czech Republic.
Objective:
Standard resective treatment of mesial temporal lobe epilepsy (MTLE) includes anteromesial temporal resection or amygdalohippocampectomy. One potential risk of these surgeries, especially in patients with magnetic resonance imaging (MRI)-negative findings, is postoperative memory impairment. An alternative to resective procedures that aim to preserve the neuropsychological profile are multiple hippocampal transections (MHTs). The objective of transections is to interrupt the longitudinal pathways of the hippocampus to prevent the spread of epileptic seizures while preserving the memory circuits. Previously performed MHT procedures were guided by questionable intraoperative electrocorticography. At our institution, we have developed and tested a modified technique to achieve complete MHTs.
Methods:
Patients with pharmacoresistant unilaterally lateralized MTLE and MRI-negative findings with high risk of neuropsychologic deterioration were indicated for complete MHT. Comprehensive neuropsychological and epileptological evaluations and MRI follow-ups were conducted 1 year and 2 years postoperatively. The primary evaluated parameters were seizure reduction and significant changes in neuropsychological performance (± 1 SD).
Results:
Complete MHTs were performed on 3 patients who completed 2-year follow-up. Two MHTs were performed on the right and 1 on the left side. Two patients are classified as Engel 1 and one patient as Engel 3. Two years after surgery, neuropsychologic evaluation did not show significant decrease in memory performance and performance in majority of cognitive tests. One-year MRI follow-up showed decrease of volume of hippocampus in all 3 patients.
Conclusions:
This modified technique of MHT in patients with MTLE and MRI-negative findings led to seizure reduction while preserving their neuropsychologic performance.
Insights
This study introduces a modified multiple hippocampal transection (MHT) technique for mesial temporal lobe epilepsy (MTLE) patients with MRI-negative findings. The procedure effectively reduced seizures while preserving cognitive function and memory performance.
Area of Science:
- Neurosurgery
- Epileptology
- Neuropsychology
Background:
- Standard treatments for mesial temporal lobe epilepsy (MTLE), such as anteromesial temporal resection or amygdalohippocampectomy, carry a risk of postoperative memory impairment, particularly in patients with magnetic resonance imaging (MRI)-negative findings.
- Multiple hippocampal transections (MHTs) offer a potential alternative by interrupting hippocampal pathways to control seizures while preserving memory circuits.
Purpose of the Study:
- To evaluate a modified technique for complete multiple hippocampal transections (MHTs) in patients with pharmacoresistant, unilaterally lateralized MTLE and MRI-negative findings.
- To assess the efficacy of this MHT technique in reducing seizures and preserving neuropsychological function, specifically memory performance.
Main Methods:
- Three patients with pharmacoresistant MTLE and MRI-negative findings underwent complete MHT.
- Postoperative evaluations included comprehensive neuropsychological and epileptological assessments, as well as MRI follow-ups at 1 and 2 years.
- Primary outcomes measured were seizure reduction and significant changes in neuropsychological performance.
Main Results:
- All three patients completed the 2-year follow-up.
- Two patients achieved Engel 1 seizure outcome, and one achieved Engel 3.
- Neuropsychological testing at 2 years showed no significant decline in memory or most cognitive functions. MRI revealed hippocampal volume reduction.
Conclusions:
- The modified MHT technique successfully reduced seizures in MTLE patients with MRI-negative findings.
- This approach preserved overall neuropsychological performance, including memory, indicating its potential as a viable surgical option.
