title: Decreased interhemispheric functional connectivity in subtypes of Parkinson's disease.
abstract: Parkinson's disease (PD) can be classified into tremor-dominant (TD) subtype and akinetic-rigid (AR) subtype, which exhibit different clinical courses and prognoses. However, the neural mechanisms underlying different subtypes of PD are not well understood. Using voxel-mirrored homotopic connectivity (VMHC), we examined the homotopic resting-state functional connectivity patterns in akinetic-rigid PD (AR-PD) and tremor-dominant PD (TD-PD) to study the neural basis for these disparate manifestations of PD. Twenty-one TD-PD patients, 29 AR-PD patients and 26 normal control subjects participated in this study. Resting-state fMRI data were analyzed using VMHC. Correlations between VMHC values and each clinical characteristic were also calculated. Compared with normal control subjects and subjects with AR-PD, subjects with TD-PD exhibited significantly lower VMHC values in the posterior lobe of the cerebellum. Moreover, tremor scores and VMHC values for the cerebellum were found to be significantly negatively correlated in TD-PD patients. By contrast, subjects with AR-PD exhibited lower VMHC values in the precentral gyrus compared with normal control subjects. These findings suggest that functional coordination between homotopic brain regions is impaired in AR-PD and TD-PD patients. This study provides evidence of both cerebellum-related connectivity deficits in TD-PD. The finding that VMHC values and tremor scores were significantly correlated suggests that VMHC measurements may be of potential clinical relevance in TD-PD.
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, People's Republic of China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Hu
authors.forename: Jiuquan
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Jiang
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Zhou
authors.forename: Luqing
authors.initials: L
authors.lastname: Wei
authors.forename: Xuntao
authors.initials: X
authors.lastname: Yin
authors.forename: Ya
authors.initials: Y
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Yanling
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D001931:Brain Mapping; D003337:Corpus Callosum / Q000098:blood supply / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000145:classification* / Q000150:complications / Q000473:pathology*; D012146:Rest / Q000502:physiology; D014202:Tremor / Q000150:complications
chemical_list: D010100:Oxygen