Resting-state fMRI study on drug-naive patients with Parkinson's disease and with depression.
OBJECTIVE
This study used resting-state functional MRI (fMRI) to evaluate regional and network alterations in patients with Parkinson's disease (PD) with and without depression.


METHODS
We recruited 29 patients with PD with depression (PD-Dep), 30 patients with PD without depression (PD-NDep), and 30 normal controls. All participants underwent resting-state fMRI scans on a 3-T MR system. The amplitude of low-frequency fluctuation (ALFF) of blood oxygen level-dependent signals was used to characterise regional cerebral function. Functional integration of the brain network was evaluated by seed-based correlation approach.


RESULTS
The PD-Dep group showed significantly higher ALFF value in the left orbitofrontal area compared with both the PD-NDep and control groups (p<0.05 corrected by FWE). In patients with PD, the Hamilton Depression Rating Scale score was positively correlated with the ALFF value in the left orbitofrontal cortex (p<0.005 uncorrected). Brain network connectivity analysis revealed reduced functional connectivity of putamen in both PD subgroups. However, the PD-Dep group showed more distributed reduced connectivity in the prefrontal-limbic network than the PD-NDep group did (p<0.05 corrected by FWE).


CONCLUSIONS
Our study demonstrates that PD-Dep patients are characterised by increased regional spontaneous neural activity in the orbitofrontal area and decreased functional integration within the prefrontal-limbic network. These findings may be helpful for facilitating further understanding of the potential mechanisms underlying depression in PD.
Department of Neurology, West China Hospital, SiChuan University, , Chengdu, Sichuan, China.
Chunyan
C
Luo
Qin
Q
Chen
Wei
W
Song
Ke
K
Chen
Xiaoyan
X
Guo
Jing
J
Yang
Xiaoqi
X
Huang
Qiyong
Q
Gong
Hui-Fang
HF
Shang
D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003863:Depression / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008032:Limbic System / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D010300:Parkinson Disease / Q000503:physiopathology* / Q000523:psychology; D017397:Prefrontal Cortex / Q000503:physiopathology
Depression; Functional Imaging; Parkinson's Disease