Seizure Frequency Can Alter Brain Connectivity: Evidence from Resting-State fMRI.

Area of Science:

• Neuroscience
• Medical Imaging
• Epilepsy Research

Background:

• Seizure frequency is a critical factor influencing functional brain connectivity.
• Analyzing seizure frequency's impact is challenging due to confounding disease and medication effects in epilepsy.
• Hot-water epilepsy patients, often without long-term medication, offer a unique model to study seizure frequency's effects.

Purpose of the Study:

• To investigate the impact of seizure frequency on functional brain connectivity in hot-water epilepsy.
• To assess connectivity changes related to seizure frequency without the confounding influence of antiepileptic drugs.
• To utilize seed-based connectivity analysis to differentiate between frequent and infrequent seizure groups.

Main Methods:

• Resting-state functional MRI (fMRI) data from 36 hot-water epilepsy patients and 18 controls.
• Patients were categorized into frequent (>2/month) and infrequent (≤2/month) seizure groups.
• Seed-to-voxel connectivity analysis with 106 seeds and voxel-wise paired t-tests (corrected for false-discovery rate).

Main Results:

• Significant differences in brain connectivity were observed between frequent and infrequent seizure groups (P < .001).
• Frequent seizure patients exhibited increased medial temporal lobe connectivity and widespread poor connectivity, including the default mode network.
• Infrequent seizure patients showed focal abnormalities, with increased default mode network connectivity and decreased left entorhinal cortex connectivity.

Conclusions:

• Seizure frequency demonstrably alters functional brain connectivity, detectable via resting-state fMRI.
• Diffuse network abnormalities, default mode network involvement, and medial temporal lobe changes are associated with frequent seizures.
• Further research in common epilepsy types is needed to validate these findings.