Abnormal functional connectivity in radiologically isolated syndrome: A resting-state fMRI study

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Neurology

Background:

• Radiologically isolated syndrome (RIS) may involve psychiatric and cognitive deficits linked to resting-state functional networks.
• Neural network involvement in RIS is not well understood.

Purpose of the Study:

• To investigate functional connectivity differences in resting-state networks between RIS patients and healthy controls using fMRI.
• To correlate neuroimaging findings with cognitive performance.

Main Methods:

• Resting-state fMRI data analyzed with independent component analysis and seed-based correlation analysis.
• Neuropsychological testing administered to 25 RIS patients and 28 healthy controls.

Main Results:

• RIS patients showed significantly worse performance in memory and executive functions compared to controls.
• Abnormal functional connectivity was observed between the default mode network and frontal gyri, and the central executive network and thalamus in RIS patients.
• Higher functional connectivity between the posterior cingulate cortex and right precuneus was noted in RIS patients.

Conclusions:

• RIS patients display abnormal brain connectivity and impaired neurocognitive test performance.
• RIS should be recognized as a non-motor (neurocognitive) variant of multiple sclerosis, distinct from an incidental finding.