Lin-Lin Gao1,2, Jia-Rong Zhang1,2, Piu Chan1,2, Tao Wu1,2. 1. Department of Neurobiology, Key Laboratory on Neurodegenerative Disorders of Ministry of Education, Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing, China. 2. Beijing Key Laboratory on Parkinson's Disease, Parkinson Disease Center of Beijing Institute for Brain Disorders, Beijing, China.
Abstract
AIMS: To investigate the effects of levodopa on the basal ganglia motor circuit (BGMC) in Parkinson's disease (PD). METHODS: Thirty PD patients with asymmetrical bradykinesia and 30 control subjects were scanned using resting-state functional MRI. Functional connectivity of the BGMC was measured and compared before and after levodopa administration in patients with PD. The correlation between improvements in bradykinesia and changes in BGMC connectivity was examined. RESULTS: In the PD-off state (before medication), the posterior putamen and internal globus pallidus (GPi) had decreased connectivity while the subthalamic nucleus (STN) had enhanced connectivity within the BGMC relative to control subjects. Levodopa administration increased the connectivity of posterior putamen- and GPi-related networks but decreased the connectivity of STN-related networks. Improvements in bradykinesia were correlated with enhanced connectivity of the posterior putamen-cortical motor pathway and with decreased connectivity of the STN-thalamo-cortical motor pathway. CONCLUSION: In PD patients with asymmetrical bradykinesia, levodopa can partially normalize the connectivity of the BGMC with a larger effect on the more severely affected side. Moreover, the beneficial effect of levodopa on bradykinesia is associated with normalization of the striato-thalamo-cortical motor and STN-cortical motor pathways. Our findings inform the neural mechanism of levodopa treatment in PD.
AIMS: To investigate the effects of levodopa on the basal ganglia motor circuit (BGMC) in Parkinson's disease (PD). METHODS: Thirty PDpatients with asymmetrical bradykinesia and 30 control subjects were scanned using resting-state functional MRI. Functional connectivity of the BGMC was measured and compared before and after levodopa administration in patients with PD. The correlation between improvements in bradykinesia and changes in BGMC connectivity was examined. RESULTS: In the PD-off state (before medication), the posterior putamen and internal globus pallidus (GPi) had decreased connectivity while the subthalamic nucleus (STN) had enhanced connectivity within the BGMC relative to control subjects. Levodopa administration increased the connectivity of posterior putamen- and GPi-related networks but decreased the connectivity of STN-related networks. Improvements in bradykinesia were correlated with enhanced connectivity of the posterior putamen-cortical motor pathway and with decreased connectivity of the STN-thalamo-cortical motor pathway. CONCLUSION: In PDpatients with asymmetrical bradykinesia, levodopa can partially normalize the connectivity of the BGMC with a larger effect on the more severely affected side. Moreover, the beneficial effect of levodopa on bradykinesia is associated with normalization of the striato-thalamo-cortical motor and STN-cortical motor pathways. Our findings inform the neural mechanism of levodopa treatment in PD.
Authors: Yang Shen; Jun Hu; Yong Chen; Wan Liu; Yuqian Li; Lei Yan; Chunming Xie; Wenbin Zhang; Miao Yu; Weiguo Liu Journal: Front Neurosci Date: 2020-07-08 Impact factor: 4.677