title: Regional homogeneity alterations differentiate between tremor dominant and postural instability gait difficulty subtypes of Parkinson's disease.
abstract: Parkinson's disease (PD) can be classified into the tremor dominant (TD) subtype and the postural instability gait difficulty (PIGD) subtype, which present with different clinical courses and prognoses. However, the symptom-specific intrinsic neural mechanisms underlying the subtypes of PD still remain elusive. In the current study, we utilized resting-state fMRI (rs-fMRI) combined with the regional homogeneity (ReHo) method to investigate the modulations of neural activity in 13 patients with predominantly PIGD (p-PIGD) and 15 patients with predominantly TD (p-TD) in the resting state. Compared with healthy controls, the p-PIGD and the p-TD groups both displayed ReHo changes in the default mode network (DMN). By contrast, the p-TD group exhibited more ReHo alterations in the cerebellum involved in the cerebello-thalamo-cortical (CTC) loops, whilst the p-PIGD group in extensive cortical and sub-cortical areas, including the frontal, parietal, occipital, temporal, limbic lobes, basal ganglia and thalamus, which are involved in the striatal-thalamo-cortical (STC) loops. Direct comparison between the two groups showed significant ReHo alterations in the primary visual cortex. Our findings underscore the differential involvement of the STC and CTC circuits underlying the two subtypes of PD. Moreover, relatively widespread neural activity abnormality, especially in the motor-related regions as well as the visual network, is apparently a characteristic feature of PIGD symptoms. This study could shed light on the underlying pathophysiology and clinical heterogeneity of PD presentation.
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Siming
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Tong
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Qinrong
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China. kezhong_zhang1969@126.com.
authors.forename: Kezhong
authors.initials: K
authors.lastname: Zhang
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D010300:Parkinson Disease / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology*; D010641:Phenotype; D004856:Postural Balance / Q000502:physiology; D014202:Tremor / Q000209:etiology / Q000473:pathology / Q000503:physiopathology
keywords: Parkinson’s disease; Postural instability gait difficulty; Regional homogeneity; Tremor-dominant