Brain network alterations in cervical dystonia: Evidence based on graph theory analysis

Cervical dystonia (CD) is the most prevalent form of isolated focal dystonia. Previous studies have shown that CD is a distributed brain network disorder, but the specific brain regions underlying these abnormalities remain poorly understood. In this study, we aimed to identify aberrant brain regions associated with CD through a data-driven approach.

EEG signals were recorded from 16 CD patients and 15 healthy controls (HC). These signals were mapped from the scalp to the cerebral cortex using source localization techniques. Functional connectivity (FC) across five frequency bands was quantified using the weighted phase lag index (wPLI). Network topology was then analyzed using Network-Based Statistics (NBS) and graph theoretical metrics, with correlations made to clinical severity scores.

Compared to HC, patients with CD showed widespread brain network alterations across multiple frequency bands. In the α frequency band, the FC of CD patients decreased, which may be related to impaired motor control function. Conversely, in the β and low γ frequency range, FC was increased in CD patients, suggesting abnormalities in sensory processing and cortical inhibitory function. Notably, the node strength of caudate nucleus may serve as a biomarker for assessing the severity of CD. Additionally, a unique modular structure involving the thalamus and sensorimotor cortex was identified in the β frequency band of CD patients, suggesting abnormal sensory-motor integration circuits.

These findings provide novel insights into the pathophysiological mechanisms of CD and are instrumental in advancing diagnostic and therapeutic strategies.