Anatomic consistencies across epilepsies: a stereotactic-EEG informed high-resolution structural connectivity study

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Drug-resistant epilepsies are increasingly viewed as network disorders.
• The precise relationship between the epileptogenic network and overall brain anatomy is not fully understood.

Purpose of the Study:

• To investigate structural connectivity changes in drug-resistant localization-related epilepsies.
• To determine if connectivity alterations are confined to the epileptogenic network or affect broader brain systems.

Main Methods:

• Diffusion weighted imaging (DWI) and high-resolution structural connectivity analysis were used.
• Stereo-electroencephalography (SEEG)-defined epileptic regions and whole-brain analyses were performed in 15 epilepsy patients and 36 controls.
• Zone-based and whole-brain analyses compared connectivity in patients and controls, correlating findings with clinical features.

Main Results:

• No significant decrease in structural connectivity within the epilepsy network nodes was found at the group level.
• Significant differences in structural connectivity between epileptogenic network nodes and the rest of the brain were observed in patients.
• Whole-brain analysis revealed widespread decreased structural connectivity, particularly within the salience and default mode networks.

Conclusions:

• Structural connectivity disintegration in epilepsy primarily affects distributed functional networks rather than solely the epileptogenic network.
• These findings highlight a network-level disruption in epilepsy that extends beyond seizure generation regions.
• The study suggests that targeting these broader network alterations may be crucial for future epilepsy treatments.