Mesial temporal lobe epilepsy diminishes functional connectivity during emotion perception.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Epilepsy Research

Background:

• Unilateral mesial temporal lobe epilepsy (MTLE) is linked to difficulties recognizing emotional facial expressions.
• Previous imaging studies show reduced activity in the amygdala and face processing regions in MTLE patients.
• Functional connectivity within emotion perception networks has not been previously investigated in MTLE.

Purpose of the Study:

• To investigate intrinsic functional connectivity (FC) in brain regions involved in emotion perception.
• To examine how FC is modulated by the perception of dynamic fearful faces.
• To compare FC patterns between healthy individuals and patients with left MTLE, right MTLE, and extratemporal epilepsy.

Main Methods:

• Identified regions of interest (ROIs) using activation analysis with dynamic fearful faces and landscapes in healthy individuals.
• Examined intrinsic functional connectivity (FC) between these ROIs during fearful face perception.
• Recruited drug-refractory patients with left MTLE (n=16), right MTLE (n=17), extratemporal epilepsy (n=15), and healthy controls (n=15).

Main Results:

• Healthy controls displayed a widespread functional network for processing fearful faces, including bilateral amygdalae and various cortical and subcortical regions.
• Patients with left MTLE showed a reduced network centered on the right amygdala, involving frontal and temporal regions.
• Patients with right MTLE exhibited minimal significant functional connectivity, while the extratemporal epilepsy group maintained a normal network.

Conclusions:

• Facial emotion perception networks are significantly altered in both left and right MTLE, with more pronounced changes in right MTLE.
• These disruptions in functional network architecture likely contribute to the impaired facial emotion recognition observed in MTLE patients.
• Findings suggest that the observed network alterations are specific to MTLE and not attributable to general epilepsy or antiepileptic medication effects.