Electroencephalography-Derived Functional Connectivity in Sensorimotor Networks in Post Stroke Fatigue

Area of Science:

• Neuroscience
• Biomedical Engineering
• Rehabilitation Science

Background:

• Fatigue in stroke survivors is associated with poor suppression of sensory information.
• This diminished sensory attenuation correlates with altered resting-state functional connectivity.
• The study investigates electroencephalography (EEG)-derived functional connectivity in the somatosensory network as a potential fatigue signature.

Purpose of the Study:

• To test the hypothesis that altered functional connectivity in the somatosensory network (beta band) is a signature of fatigue in post-stroke survivors.
• To explore the relationship between brain network properties and fatigue levels in individuals with stroke.

Main Methods:

• Resting-state electroencephalography (EEG) was used to measure neuronal activity in 29 non-depressed, minimally impaired stroke survivors.
• Graph theory-based network analysis calculated the small-world index (SW) for somatosensory and motor networks in the beta frequency band (13-30 Hz).
• Fatigue Severity Scale (FSS) scores were used, with scores > 4 indicating high fatigue.

Main Results:

• Stroke survivors with high fatigue exhibited significantly higher small-worldness in somatosensory networks compared to those with low fatigue.
• This finding confirmed the hypothesis linking altered functional connectivity to fatigue.

Conclusions:

• Elevated small-worldness in somatosensory networks suggests impaired processing of somatosensory input in fatigued stroke survivors.
• This altered sensory processing may explain the heightened perception of effort within the sensory attenuation model of fatigue.