Alterations of brain activity in different motor subtypes of Parkinson disease based on regional homogeneity analysis / 中华放射学杂志

Objective To explore the changes and significance of local brain activity in different motor subtypes of Parkinson disease(PD) using resting-state functional MRI (rs-fMRI) based on regional homogeneity (ReHo) analysis. Methods A total of 84 PD patients and age-and gender-matched 29 healthy controls undergoing rs-fMRI were included. PD patients were divided into two groups of tremor dominant (TD) (n=45) and postural instability gait difficulty(PIGD) (n=39) according to the Unified Parkinson′s Disease Rating Scale (UPDRS) scores. Data processing assistant for resting-state fMRI (DPARSF) and resting-state fMRI data analysis Toolkit (REST) V1.8 based on MATLAB were used to calculate the ReHo which measured brain activity in different motor subtypes of PD. Analysis of covariance and post-hoc t-tests were performed to detect the differences of local brain activity among the three groups.Correlation analyses were performed between ReHo values of the regions showing group differences and TD and PIGD scores respectively. Results Compared to healthy controls, the TD group exhibited increased ReHo in the right superior and middle frontal gyrus, left cerebellum(13 to 21 voxels, P<0.05), while decreased ReHo in the left temporal lobule, left putamen, left paracentral lobule, and bilateral thalamus (12 to 91 voxels, P<0.05). The PIGD group showed increased ReHo in the right superior frontal gyrus, right middle frontal gyrus and anterior cingulate gyrus (ACC) (55 to 92 voxels, P<0.05), while decreased ReHo in the left putamen, left pallidum, left temporal lobule, right occipital lobule, bilateral thalamus, bilateral middle cingulate gyrus, bilateral supplementary motor area (SMA) (15 to 78 voxels, P<0.05). Compared with PIGD, the TD group showed increased ReHo in the left temporal lobule, left cerebellum, bilateral middle cingulate gyrus (19 to 51 voxels, P<0.05), whereas decreased ReHo in the left paracentral lobule, bilateral cuneus, right superior frontal gyrus, and right ACC (14 to 68 voxels, P<0.05). Additionally, ReHo in the left thalamus and left putamen negatively correlated with TD scores (r=-0.355 and －0.498, both P<0.05). ReHo in the left thalamus and right thalamus negatively correlated with PIGD scores (r=-0.478 and－0.397, both P<0.05). Conclusions The changes of brain activity in TD are located in the cerebello-thalamo-cortical (CTC) circuit and the striatal-thalamo-cortical (STC) loop while the changes in PIGD are largely located in the STC loop and visual network cortex. This specific pattern of intrinsic activity in TD and PIGD may provide insights into the neurophysiological mechanisms of PD with different motor subtypes.

Alterations of brain activity in different motor subtypes of Parkinson disease based on regional homogeneity analysis / 中华放射学杂志

Objective@#To explore the changes and significance of local brain activity in different motor subtypes of Parkinson disease(PD) using resting-state functional MRI (rs-fMRI) based on regional homogeneity (ReHo) analysis.@*Methods@#A total of 84 PD patients and age-and gender-matched 29 healthy controls undergoing rs-fMRI were included. PD patients were divided into two groups of tremor dominant(TD) (n=45) and postural instability gait difficulty(PIGD) (n=39) according to the Unified Parkinson′s Disease Rating Scale (UPDRS) scores. Data processing assistant for resting-state fMRI (DPARSF) and resting-state fMRI data analysis Toolkit (REST) V1.8 based on MATLAB were used to calculate the ReHo which measured brain activity in different motor subtypes of PD. Analysis of covariance and post-hoc t-tests were performed to detect the differences of local brain activity among the three groups.Correlation analyses were performed between ReHo values of the regions showing group differences and TD and PIGD scores respectively.@*Results@#Compared to healthy controls, the TD group exhibited increased ReHo in the right superior and middle frontal gyrus, left cerebellum(13 to 21 voxels, P<0.05), while decreased ReHo in the left temporal lobule, left putamen, left paracentral lobule, and bilateral thalamus (12 to 91 voxels, P<0.05). The PIGD group showed increased ReHo in the right superior frontal gyrus, right middle frontal gyrus and anterior cingulate gyrus (ACC) (55 to 92 voxels, P<0.05), while decreased ReHo in the left putamen, left pallidum, left temporal lobule, right occipital lobule, bilateral thalamus, bilateral middle cingulate gyrus, bilateral supplementary motor area (SMA) (15 to 78 voxels, P<0.05). Compared with PIGD, the TD group showed increased ReHo in the left temporal lobule, left cerebellum, bilateral middle cingulate gyrus (19 to 51 voxels, P<0.05), whereas decreased ReHo in the left paracentral lobule, bilateral cuneus, right superior frontal gyrus, and right ACC (14 to 68 voxels, P<0.05). Additionally, ReHo in the left thalamus and left putamen negatively correlated with TD scores (r=-0.355 and -0.498, both P<0.05). ReHo in the left thalamus and right thalamus negatively correlated with PIGD scores (r=-0.478 and -0.397, both P<0.05).@*Conclusions@#The changes of brain activity in TD are located in the cerebello-thalamo-cortical (CTC) circuit and the striatal-thalamo-cortical (STC) loop while the changes in PIGD are largely located in the STC loop and visual network cortex. This specific pattern of intrinsic activity in TD and PIGD may provide insights into the neurophysiological mechanisms of PD with different motor subtypes.

The Predictable Clinical Factors for the Levodopa Responsiveness of Resting Tremor in Patients with Parkinson's Disease

BACKGROUND: The pathophysiology of resting tremor in Parkinsons disease (PD) remains unclear. Dopaminergic treatment provides variable effects on resting tremor in PD. We aimed to evaluate the predictable clinical factors for the levodopa responsiveness of resting tremor in patients with PD. METHODS: Eighty-five PD patients with prominent resting tremor who visited Asan Medical Center between June 2004 and June 2005 were included. The prominent resting tremor was defined as tremor scoring more than 3 in at least one limb in the Unified Parkinsons Disease Rating Scale (UPDRS). Subjects were divided into the responsive group (RG) or non-responsive group (NRG) according to the responsiveness of resting tremor to dopaminergic treatment. Responsiveness was defined as a minimum 2 points reduction of UPDRS score for the resting tremor after dopaminergic treatment for more than 3 months. RESULTS: Among the 85 patients, there were 35 men and 50 women ages 34-87 years (mean age, 67 years). Thirty-six patients (42.4%) were grouped into RG and 49 (57.6%) into NRG. Mean age of RG was significantly younger than that of NRG. RG showed significantly higher initial UPDRS part III subtotal score (p=0.015) and more severe Hoehn & Yahr stage (p=0.010) than those of NRG. UPDRS subscores for rigidity (p=0.012), bradykinesia (p=0.021) and postural impairment (p=0.018) were correlated with the responsiveness of dopaminergic treatment. CONCLUSIONS: Resting tremor in PD patients more favorably responded to dopaminergic treatment when it presented in combination with bradykinesia and rigidity suggesting dopaminergic role in the genesis of resting tremor in those PD patients.