Resting-State Functional MRI Regional Homogeneity Correlates With Motor Scores in Parkinson's Disease

Abstract

Background and Purpose

This study investigated the neural mechanisms underlying Parkinson's disease (PD) subtypes—tremor dominant (TD) and postural instability gait difficulty (PIGD)—by analyzing regional homogeneity (ReHo) values from resting-state functional MRI.

Methods

Fifty-nine PD patients (29 TD patients, 30 PIGD patients) and 30 healthy controls (HCs) were enrolled. ReHo values were analyzed via analysis of variance and a two-sample t-test, with age and sex as covariates. Correlations between ReHo values and clinical motor symptoms were also examined.

Results

Distinct ReHo patterns were observed in patients with the PD subtypes and HCs. TD patients presented decreased ReHo in the cerebellar–thalamic–cortical circuit, whereas PIGD patients presented lower ReHo in the striatum and supplementary motor area (SMA). TD patients had higher ReHo in the bilateral dorsolateral superior frontal gyrus and SMA but lower ReHo in the bilateral medial orbital part of the superior frontal gyrus and other regions on the left than PIGD patients. Specific brain area ReHo values were correlated with tremor scores, PIGD scores, and rigidity scores.

Conclusion

Different motor subtypes of PD patients and HCs showed distinct ReHo patterns. ReHo correlation with clinical traits suggests its value as a biomarker for subtype-specific diagnostic strategies.