Ictal Bruxism in Temporal Lobe Epilepsy: Intracranial EEG Connectivity Study

Area of Science:

• Epilepsy research
• Neurophysiology
• Neurosurgery

Background:

• Ictal bruxism is a rare motor seizure manifestation in temporal lobe epilepsy.
• Its underlying brain network mechanisms remain poorly understood.
• Distinguishing it from other oro-alimentary automatisms is crucial for treatment.

Purpose of the Study:

• To characterize the brain networks involved in ictal bruxism using SEEG.
• To differentiate ictal bruxism from other oro-alimentary automatisms in temporal lobe epilepsy.
• To inform surgical localization and improve outcomes for drug-resistant epilepsy.

Main Methods:

• Stereoelectroencephalography (SEEG) recorded spontaneous and stimulated seizures.
• Analysis included seizure origin, propagation, and cortical stimulation mapping.
• Time-frequency and coherence analyses examined brain synchrony in specific frequency bands.

Main Results:

• Seizures originated in the superior temporal gyrus, propagating to anterior insulo-opercular regions.
• Direct cortical stimulation of the superior temporal gyrus and anterior ventral insula induced seizures and bruxism.
• Increased beta and gamma band synchrony was observed between the superior temporal gyrus/anterior ventral insula and opercular regions during bruxism.

Conclusions:

• Ictal bruxism is a network phenomenon in temporal lobe epilepsy, separate from mesial temporal lobe networks.
• It differs from oro-alimentary automatisms like lip smacking.
• Accurate network characterization is vital for optimizing surgical interventions in epilepsy.