A resting-state functional MRI study on amplitude of low-frequency fluctuation and functional connectivity alteration of parkinson′s disease with apathy / 中华放射学杂志

ABSTRACT

Objective:To investigate the alterations of amplitude of low frequency fluctuation (ALFF) and functional connectivity (FC) in patients with Parkinson′s disease (PD) with apathy.Methods:From May 2016 to August 2019, PD patients and age-, gender-and education level-matched healthy controls (HC) in the First Affiliated Hospital of Nanjing Medical University were prospectively recruited. The clinical and resting-state functional MRI (rs-fMRI) data of PD patients and HC were analyzed. According to the Starkstein Apathy Scale (SAS) scores, PD patients were divided into PD with apathy (PD-A) group and PD without apathy (PD-NA) group. Rs-fMRI images were processed by DPABI based on MATLAB. ALFF values were calculated and the standard ALFF (zALFF) were obtained. ANOVA and Post-Hoc t test were performed to compare the differences in local brain activity among the three groups. The brain regions with significant different zALFF values were selected as the seeds to calculate the FC values of the whole brain. The associations between FC values and the SAS scores were performed using pearson correlation analyses. Results:A total of 75 PD patients (50 males, 25 females, aged from 44 to 88 years) and 41 HC (25 males, 16 females, aged from 54 to 72 years) were enrolled. There were 42 patients in the PD-A group and 33 patients in the PD-NA group. Significant differences were found in zALFF values among the PD-A, PD-NA and HC groups ( P<0.05). After Post-Hoc t test, compared with the HC group, zALFF values were significantly increased in the right middle frontal gyrus in the PD-A group ( P<0.05) and significantly decreased in the left precuneus in the PD-NA group; The zALFF values of the right middle frontal gyrus and left precuneus in the PD-A group were significantly higher than those in PD-NA group ( P<0.05). Brain regions with different zALFF values were used as seeds for whole-brain FC. Compared with PD-NA group, FC values between the right middle frontal gyrus and bilateral precuneus, left superior frontal gyrus and its medial side, left middle frontal gyrus, left angular, left anterior cingulate gyrus, left posterior cingulate gyrus, left parahippocampal gyrus were significantly decreased in the PD-A group ( P<0.05). Additionally, FC values of PD patients between the right middle frontal gyrus with the left precuneus, the left superior frontal gyrus and its medial side, and the left middle frontal gyrus were negatively correlated with SAS scores ( r=-0.31, -0.30 and -0.34, both P<0.05). Conclusion:PD-A and PD-NA patients have different brain functional activities and connections in the frontal lobe, parietal lobe and limbic system, suggesting that apathy in PD may be associated with the abnormal functional connections of the frontal-parietal cortical circuit and the frontal-limbic-striatal loop.