Unruptured brain arteriovenous malformations causing seizures localize to one common brain network

Area of Science:

• Neurology
• Neuroimaging
• Neurosurgery

Background:

• Seizures are a frequent clinical manifestation of unruptured brain arteriovenous malformations (bAVMs).
• The precise brain regions underlying seizure generation in bAVMs remain incompletely understood.
• Identifying these regions is crucial for predicting seizure risk and guiding treatment strategies.

Purpose of the Study:

• To identify specific brain regions and networks causally associated with seizures in patients with unruptured bAVMs.
• To develop a neuroimaging biomarker for predicting seizure risk in bAVM patients.
• To investigate the involvement of canonical resting-state networks in bAVM-related seizures.

Main Methods:

• Retrospective analysis of 220 patients with unruptured bAVMs.
• Voxel-based lesion-symptom mapping (VLSM) to correlate bAVM location with seizures.
• Lesion network mapping (LNM) to identify distributed brain networks involved in seizures.
• Calculation of individualized network damage scores for risk stratification.
• Overlap analysis with canonical resting-state networks.

Main Results:

• Unruptured bAVMs causing seizures exhibited anatomical heterogeneity at the voxel level.
• LNM identified a seizure network connected to the left caudate and precuneus.
• Network damage scores effectively stratified patients into low-, medium-, and high-risk seizure groups (p < .005).
• The frontoparietal control, limbic, and default mode networks showed significant overlap (>50%) with seizure-susceptible regions.

Conclusions:

• Specific brain regions and functional networks are implicated in seizures associated with unruptured bAVMs.
• The identified seizure network and associated damage scores may serve as a neuroimaging biomarker for seizure risk prediction.
• Understanding the involvement of resting-state networks provides insights into the pathophysiology of bAVM-related seizures.