Association of Piriform Cortex Resection With Surgical Outcomes in Patients With Temporal Lobe Epilepsy

Area of Science:

• Neurosurgery
• Epileptology
• Neuroimaging

Background:

• The piriform cortex, specifically area tempestas, is implicated in seizure modulation in animal models.
• Evidence for the piriform cortex's role in human temporal lobe epilepsy (TLE) is limited.
• Understanding the piriform cortex's function is crucial for optimizing TLE treatment.

Purpose of the Study:

• To determine if piriform cortex removal correlates with seizure freedom in TLE patients.
• To provide proof-of-concept for the piriform cortex's relevance in human TLE.
• To investigate the piriform cortex's role in seizure generation.

Main Methods:

• A cohort study involving 107 TLE patients undergoing epilepsy surgery.
• Structural magnetic resonance imaging (MRI) with voxel-based morphometry and volumetry.
• Analysis of presurgical and postsurgical scans with a median 5-year follow-up, validated in two independent cohorts.

Main Results:

• Seizure-free patients had reduced postsurgical gray matter volumes in the ipsilateral piriform cortex.
• A significantly larger proportion of the piriform cortex was resected in seizure-free individuals (83% vs. 52%).
• Resection of at least half the piriform cortex increased seizure freedom odds by 16-fold, independently validated.

Conclusions:

• Piriform cortex resection is associated with long-term seizure freedom in TLE.
• These findings underscore the piriform cortex's critical role in TLE seizure generation.
• The study supports the inclusion of piriform cortex removal in TLE neurosurgical treatment strategies.