Related Experiment Video
Updated: Feb 17, 2026
Anteromesial Temporal Lobectomy for Medically Intractable Temporal Lobe Epilepsy: An Operative Study
Published on: August 15, 2025
Parahippocampectomy as a New Surgical Approach to Mesial Temporal Lobe Epilepsy Caused By Hippocampal Sclerosis: A
Mario Arturo Alonso-Vanegas1, Iván D Freire Carlier1, Daniel San-Juan2
1Department of Neurosurgery, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
Background And Objective:
The parahippocampal gyrus plays an important role in the epileptogenic pathways of mesial temporal lobe epilepsy caused by hippocampal sclerosis (mTLE-HS); its resection could prevent epileptic seizures with fewer complications. This study evaluates the initial efficacy and safety of anterior temporal lobectomy (ATL), selective amygdalohipppocampectomy (SAH), and parahippocampectomy (PHC) surgical approaches in mTLE-HS.
Methods:
A randomized comparative pilot clinical trial (2008-2011) was performed that included patients with mTLE-HS who underwent ATL, trans-T3 SAH, and trans-T3 PHC. Their sociodemographic characteristics, visual field profiles, verbal and visual memory profiles, and Engel scale outcome at baseline and at 1 and 5 years are described, using descriptive statistics along with parametric and nonparametric tests.
Results:
Forty-three patients with a mean age of 35.2 years (18-56 years), 65% female, were analyzed: 14 underwent PHC, 14 ATL, and 15 SAH. The following percentages refer to those patients who were seizure free (Engel class IA) at 1-year and 5-year follow-up, respectively: 42.9% PHC, 71.4% ATL, and 60% SAH (P = 0.304); 28.6% PHC, 50% ATL, and 53.3% SAH (P = 0.353). Postoperative visual field deficits were 0% PHC, 85.7% ATL, and 46.7% SAH (P = 0.001). Verbal and/or visual memory worsening were present in 21.3% PHC, 42.8% ATL, and 33.4% SAH (P = 0.488) and preoperative and postoperative visual memory scores were significantly different in the SAH group only (P = 0.046).
Conclusions:
PHC, ALT, and SAH show a preliminary similar efficacy in short-term seizure-free rates in patients with mTLE-HS. However, PHC efficacy in the long-term decreases compared with the other surgical techniques. PHC does not produce postoperative visual field deficits.
Insights
This study compared surgical options for mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS). While anterior temporal lobectomy (ATL) and selective amygdalohippocampectomy (SAH) showed sustained seizure control, parahippocampal gyrus resection (PHC) had decreasing efficacy over time but preserved visual fields.
Area of Science:
- Neurosurgery
- Epileptology
- Clinical Neurology
Background:
- The parahippocampal gyrus is implicated in the epileptogenic zone of mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS).
- Resection of this area may offer seizure control with reduced complications.
- This study compares surgical interventions for mTLE-HS.
Purpose of the Study:
- To evaluate the initial efficacy and safety of three surgical approaches for mTLE-HS: anterior temporal lobectomy (ATL), selective amygdalohippocampectomy (SAH), and parahippocampal gyrus resection (PHC).
Main Methods:
- A randomized comparative pilot clinical trial included 43 patients with mTLE-HS undergoing ATL, trans-T3 SAH, or trans-T3 PHC.
- Patients were assessed for sociodemographic characteristics, visual field and memory profiles, and Engel scale outcomes at baseline and at 1 and 5 years.
- Descriptive statistics and parametric/nonparametric tests were used for analysis.
Main Results:
- At 5-year follow-up, seizure-free rates (Engel class IA) were 28.6% for PHC, 50% for ATL, and 53.3% for SAH.
- Postoperative visual field deficits were significantly lower in the PHC group (0%) compared to ATL (85.7%) and SAH (46.7%) (P=0.001).
- Verbal and/or visual memory worsening occurred in 21.3% of PHC, 42.8% of ATL, and 33.4% of SAH patients, with significant decline in SAH group only.
Conclusions:
- PHC, ATL, and SAH demonstrate similar short-term seizure-free rates in mTLE-HS patients.
- Long-term seizure control efficacy of PHC diminishes compared to ATL and SAH.
- PHC surgery is associated with no postoperative visual field deficits, offering a distinct safety profile.
