Patterned functional network disruption in amyotrophic lateral sclerosis.

Area of Science:

• Neuroscience
• Neurology
• Biomarkers

Background:

• Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease impacting motor function and showing nonmotor involvement.
• ALS is increasingly recognized as a multisystem network disorder with impaired connectivity.
• The precise neuroelectric characteristics of impaired cortical communication in ALS require further elucidation.

Purpose of the Study:

• To characterize changes in functional connectivity using electroencephalography (EEG) in ALS patients.
• To quantify spatiospectral characteristics of network changes in ALS.
• To investigate the correlation between network changes and clinical/structural markers.

Main Methods:

• Resting-state EEG recordings from 74 ALS patients and 47 healthy controls.
• Beamformer source analysis to assess functional connectivity.
• Quantification using spectral power, amplitude envelope correlation (co-modulation), and imaginary coherence (synchrony).

Main Results:

• Decreased spectral power observed in occipital, temporal, orbitofrontal, and sensorimotor regions across various frequency bands (δ to β).
• Increased neural oscillation co-modulation in central, posterior, and frontal regions (δ, θ, γ_l bands).
• Decreased synchrony noted in temporal, frontal, and sensorimotor regions (δ to β bands).

Conclusions:

• ALS exhibits characteristic patterned changes in cortical function, signifying widespread network disruption.
• Both motor and nonmotor networks are extensively dysfunctional in ALS.
• These findings support the development of network disruption biomarkers for ALS clinical trials.