Objective: The primary objective was to explore distinctions in the fractional amplitude of low-frequency fluctuation (fALFF) indicator among early-stage parkinsonian variant of multiple system atrophy (MSA-P) and Parkinson’s Disease (PD) patients. Additionally, we sought to investigate variations in functional connectivity (FC) between the two diseases and evaluate the diagnostic and discriminatory utility of fALFF for the two conditions.

Background: The overlapping clinical manifestations in MSA-P and PD can complicate clinical diagnostic accuracy, particularly in the early stage. The study aims to uncover shared and distinctive patterns of brain function in the initial phase of the two conditions by utilizing resting-state functional characteristic.

Method: We recruited 24 MSA-P patients, 34 PD patients and 27 matched healthy controls (HC). The voxel-wise fALFF was compared to characterize regional brain function, and corresponding seed-based FC was evaluated subsequently. Receiver operating characteristic (ROC) analyses were used to examine diagnostic accuracy of fALFF.

Results: Compared to HC, decreased fALFF was observed in the bilateral basal ganglia (BG) of MSA-P patients, while decreased fALFF was only identified in the left BG of PD patients. Additionally, elevated fALFF was found in the superior cerebellum for MSA-P patients and the temporo-occipital cortex for PD patients. Furthermore, we found that PD patients exhibited increased FC in the cortico-striatal loop compared to MSA-P patients. The fALFF of the left caudate achieved an area under the receiver operating characteristic curve (AUC) of 0.838 for distinguishing MSA-P from HC (P < 0.001) and 0.772 for MSA-P from PD (P < 0.001). The fALFF of the left putamen resulted in an AUC of 0.736 for distinguishing PD from HC (P = 0.002) [figure1].

Conclusion: Our findings indicated the presence of both common and distinct abnormalities in spontaneous brain activity within the BG, cerebellum, and cortices in both MSA-P and PD patients at early stage. PD patients may employ more compensatory mechanisms than MSA-P patients. Furthermore, the resting-state functional indicator fALFF may aid in the early differentiation between MSA-P and PD.

[figure1]

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/comparison-of-spontaneous-brain-activity-in-distinguishing-parkinsonian-variant-of-multiple-system-atrophy-from-parkinsons-disease-at-early-stage/