Altered regional homogeneity in motor cortices in patients with multiple system atrophy.

Typical histopathological findings of multiple system atrophy (MSA) have been observed in motor related cortices, in addition to the common areas of the striatum, substantia nigra, olivopontocerebellar pathways, the intermediolateral cell columns of the spinal cord, and the cerebellum. The purpose of this study is to test the hypothesis that functional impairment associated with the histopathological findings exists in the motor cortex of MSA patients using resting-state fMRI. Twenty clinically probable MSA patients (9 with MSA-P and 11 with MSA-C subtype) and 11 healthy controls (HCs) were studied. The regional homogeneity (ReHo) approach was used to analyze low frequency spontaneous fluctuation of blood oxygen level dependent signal. Compared with the HCs, the MSA patients showed significantly decreased ReHo in the left primary sensorimotor cortex, posterior cingulate cortex, left lateral prefrontal cortex (PFC) and right inferior parietal lobule (IPL), together with increased ReHo in the right primary sensorimotor cortex, bilateral premotor cortices, bilateral supplementary motor areas, medial PFC and left IPL. The results support the hypothesis that motor cortex areas can be functionally involved and likely play a role in motor circuit dysfunction in MSA patients.