The Anatomo-Electrical Network Underlying Hypermotor Seizures

Area of Science:

• Neuroscience
• Epileptology
• Medical Imaging

Background:

• Hypermotor seizures (HMS) can originate from various brain regions, suggesting potential shared underlying neural networks.
• Understanding these networks is crucial for diagnosing and treating HMS.

Purpose of the Study:

• To investigate the specialized neural networks associated with HMS.
• To analyze interictal 18FDG-PET imaging and ictal SEEG recordings in HMS patients.

Main Methods:

• Retrospective analysis of 14 HMS patients, classified into HMS1 and HMS2 based on seizure characteristics.
• Comparison of interictal PET data with 18 healthy controls using statistical parametric mapping to identify hypometabolism.
• Review of ictal SEEG recordings to determine seizure onset and spreading patterns.

Main Results:

• HMS patients showed hypometabolism in the bilateral anterosuperior insular lobes, mesial premotor cortex (MPMC), middle cingulate cortex (MCC), and bilateral caudate nuclei compared to controls.
• HMS1 patients exhibited more extensive hypometabolism, including orbitofrontal cortex (OFC), temporal pole, and anterior cingulate cortex (ACC), than HMS2 patients.
• SEEG data indicated common recruitment of the insula, MCC, and MPMC at seizure onset.

Conclusions:

• A distinct interictal hypometabolic pattern was identified in HMS patients.
• A network comprising the anterosuperior insula, mesiofrontal cortex (MCC-MPMC), and caudate nucleus likely contributes to HMS generation.
• The ACC, OFC, and temporal pole may be involved in the affective aspects of HMS.