Hippocampal morphometry in sudden and unexpected death in epilepsy

Area of Science:

• Neuropathology
• Epilepsy Research
• Forensic Pathology

Background:

• Sudden unexpected death in epilepsy (SUDEP) is a leading cause of mortality in epilepsy patients.
• Identifying reliable biomarkers for SUDEP is crucial for risk stratification and prevention strategies.
• Hippocampal morphometric abnormalities have been investigated as potential SUDEP indicators.

Purpose of the Study:

• To investigate hippocampal morphometric measures, including granule cell dispersion and malrotation features, as potential biomarkers for SUDEP.
• To analyze postmortem hippocampal tissue from SUDEP, epilepsy control, and nonepilepsy control groups.

Main Methods:

• Retrospective analysis of 187 postmortem cases (SUDEP, epilepsy controls, nonepilepsy controls).
• Digitization and image analysis of hippocampal sections for granule cell layer thickness and dimensional measurements.
• Qualitative assessment of hippocampal malrotation features, dentate gyrus invaginations, and subicular/CA1 folds.

Main Results:

• Granule cell layer thickness was increased in cases with hippocampal sclerosis.
• No significant differences were found in hippocampal shape, medial positioning, or malrotation features across SUDEP, epilepsy control, and nonepilepsy control groups.
• Greater parahippocampal gyrus lengths were observed on the right side in the SUDEP group compared to other groups.

Conclusions:

• No hippocampal morphometric features, such as granule cell dispersion or malrotation, were identified as definitive SUDEP biomarkers.
• Observed asymmetries in parahippocampal gyrus measurements in SUDEP warrant further investigation for potential links to central autonomic network dysfunction.