Rethinking cortical hypertrophy in temporal lobe epilepsy

Area of Science:

• Neurology
• Neuroimaging
• Epilepsy Research

Background:

• Temporal lobe epilepsy (TLE) is the most common adult focal epilepsy.
• Traditionally, TLE is characterized by hippocampal and extra-hippocampal atrophy.
• Emerging evidence suggests cortical hypertrophy (increased thickness) also occurs in TLE.

Purpose of the Study:

• To synthesize evidence for cortical hypertrophy in TLE.
• To explore potential neurobiological mechanisms underlying cortical hypertrophy.
• To discuss the implications for understanding TLE as a brain remodeling disorder.

Main Methods:

• Narrative review of existing literature.
• Overview of magnetic resonance imaging (MRI) methods for measuring cortical thickness (surface-based, volume-based, voxel-based).
• Synthesis of MRI studies reporting cortical hypertrophy in TLE.

Main Results:

• Multiple studies report cortical hypertrophy in TLE, challenging unidirectional atrophy models.
• Variability exists in reported affected regions, patient cohorts, and analytical techniques.
• Potential mechanisms include seizure-related remodeling, glial/inflammatory processes, and neuroplasticity.

Conclusions:

• Cortical hypertrophy is a recognized phenomenon in TLE.
• Understanding both atrophy and hypertrophy is crucial for a comprehensive view of TLE.
• Further research is needed on the biological validity, dynamics, and clinical relevance of cortical hypertrophy in TLE.