Research Paper Volume 12, Issue 18 pp 18622—18634

Asymmetrical nigral iron accumulation in Parkinson’s disease with motor asymmetry: an explorative, longitudinal and test-retest study

Xiaojun Guan1, , Tao Guo1, , Cheng Zhou1, , Jingjing Wu1, , Ting Gao2, , Xueqin Bai1, , Hongjiang Wei4, , Yuyao Zhang5, , Min Xuan1, , Quanquan Gu1, , Peiyu Huang1, , Chunlei Liu3,6, , Baorong Zhang2, , Jiali Pu2, , Zhe Song2, , Yaping Yan2, , Feng Cui7, , Minming Zhang1, , Xiaojun Xu1, ,

  • 1 Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
  • 2 Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
  • 3 Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA
  • 4 Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
  • 5 School of Information Science and Technology, ShanghaiTech University, Shanghai, China
  • 6 Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
  • 7 Department of Radiology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou, China

Received: June 9, 2020       Accepted: July 21, 2020       Published: September 27, 2020
How to Cite

Copyright: © 2020 Guan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Parkinson’s disease (PD) is commonly characterized by asymmetrical motor impairment. This study aimed to clarify the iron distributions in PD patients with significant motor asymmetry and their longitudinal alterations. This study included 123 PD patients and 121 normal controls. Thirty-eight PD patients were revisited. PD patients with significant motor asymmetry were identified by using an objective criterion. Inter-group, inter-hemisphere and inter-visit differences of regional tissue susceptibility were analyzed. Iron accumulation in dominantly and non-dominantly affected substantia nigra (SN) were observed in PD patients with motor asymmetry compared with normal controls (p < 0.005, Bonferroni corrected). Iron accumulation in the dominantly affected SN was significantly higher than that in the non-dominantly affected SN (p < 0.01, Bonferroni corrected). After follow-up, time effect on the iron content in SN was observed, directing to decrease in PD patients with motor asymmetry without hemispherical difference (p < 0.05). In conclusion, asymmetrical iron accumulation in SN was associated with the motor asymmetry in PD at baseline, while along the disease evolution iron content in SN became longitudinally decreased. All these findings provide new evidence for PD pathogenesis that the abnormal iron metabolism in SN is complicated and not always unidirectional.


PD: Parkinson’s disease; SN: Substantia nigra; RN: Red nucleus; GP: Globus pallidus; CN: Caudate nucleus; QSM: Quantitative susceptibility mapping; LEDD: Levodopa equivalent daily dose; UPDRS: Unified Parkinson’s Disease Rating Scale; ESWAN: Enhanced susceptibility-weighted angiography.