Hippocampography Guides Consistent Mesial Resections in Neocortical Temporal Lobe Epilepsy.

Area of Science:

• Neurosurgery
• Epileptology
• Surgical Neurology

Background:

• Optimal surgical techniques for lesional neocortical temporal lobe epilepsy remain unclear.
• Hippocampal electrocorticography aims to maximize seizure freedom and minimize neuropsychological deficits by precisely identifying and resecting epileptogenic tissue.

Purpose of the Study:

• To evaluate if standardized hippocampal electrocorticography (hippocampography) leads to more consistent hippocampectomy compared to unguided resection during conventional electrocorticography focused on the lesion.

Main Methods:

• Retrospective chart review of patients undergoing electrocorticography (including hippocampography) combined with lesionectomy, anterolateral temporal lobectomy, and hippocampectomy over 8 years.
• Patients were categorized into mesial (hippocampography-guided) and lateral electrocorticography groups.
• Primary outcome measured was the deviation from the mean hippocampectomy length.

Main Results:

• Fourteen of 26 patients underwent hippocampography-guided mesial temporal resection.
• Hippocampography demonstrated 2.6 times greater consistency in resection compared to unguided methods.
• The mesial group showed a hippocampal resection range of 0.7 cm versus 1.8 cm in the lateral group (p=0.01).
• Seizure freedom was achieved in 86% of the mesial group versus 42% of the lateral group (p=0.02).

Conclusions:

• Hippocampography significantly reduces resection variability, leading to more consistent hippocampectomy than conventional unguided electrocorticography.
• Consistent hippocampal resection may prevent overresection, mitigating neuropsychological risks, and underresection, improving postoperative seizure control.