Altered Brain Network in Amyotrophic Lateral Sclerosis: A Resting Graph Theory-Based Network Study at Voxel-Wise...

Area of Science:

• Neuroscience
• Graph Theory
• Medical Imaging

Background:

• Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder impacting motor neurons.
• Neuroimaging reveals ALS affects widespread brain regions beyond motor pathways, including sensory and associative cortices.
• Understanding functional network alterations in ALS is crucial for comprehending its multisystem nature.

Purpose of the Study:

• To investigate whole-brain, voxel-wise functional network abnormalities using graph theory in ALS patients.
• To identify specific brain regions with altered network organization in ALS.
• To explore the relationship between functional network alterations and disease severity.

Main Methods:

• Employed graph theory analysis, specifically voxel-wise network degree centrality (DC), to assess functional brain networks.
• Compared network DC between 43 ALS patients and 44 healthy controls.
• Correlated DC z-scores in specific regions with ALS Functional Rating Scale-Revised (ALSFRS-r) scores.

Main Results:

• ALS patients exhibited significant alterations in network DC across multiple brain regions compared to controls.
• Increased DC was observed in cerebellum, occipital, and frontal lobes; decreased DC in motor, sensory, temporal, cingulate, and precuneus regions.
• A negative correlation was found between DC in the right inferior occipital gyrus and ALSFRS-r scores, indicating a link between visual cortex network changes and disease severity.

Conclusions:

• ALS is a multisystem disorder with widespread functional network abnormalities extending beyond motor areas.
• Altered functional connectivity in visual processing areas is a feature of ALS.
• Network DC in the right inferior occipital gyrus may serve as a potential biomarker for assessing ALS disease severity.