Dopaminergic Modulation of Arm Swing During Gait Among Parkinson's Disease Patients

Article type: Research Article

Authors: Sterling, Nicholas W.^; | Cusumano, Joseph P. | Shaham, Noam | Piazza, Stephen J. | Liu, Guodong | Kong, Lan | Du, Guangwei | Lewis, Mechelle M.^; | Huang, Xuemei^{; ; ; ;}

Affiliations: Department of Neurology, The Pennsylvania State University – Milton S. Hershey Medical Center, Hershey, PA, USA | Department of Public Health Sciences, The Pennsylvania State University – Milton S. Hershey Medical Center, Hershey, PA, USA | Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA | Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA | Department of Pharmacology, The Pennsylvania State University – Milton S. Hershey Medical Center, Hershey, PA, USA | Department of Radiology, The Pennsylvania State University – Milton S. Hershey Medical Center, Hershey, PA, USA | Department of Neurosurgery, The Pennsylvania State University – Milton S. Hershey Medical Center, Hershey, PA, USA

Note: [] Correspondence to: Xuemei Huang, M.D., Ph.D., Professor and Vice Chair of Research, Department of Neurology, Penn State Hershey Medical Center, 500 University Dr., H-037 Hershey, PA 17033-0850, USA. Tel.: +1 717 531 0003/Ext.: 287082; Fax: +1 717 531 0226; E-mail: xuemei@psu.edu

Abstract: Background: Reduced arm swing amplitude, symmetry, and coordination during gait have been reported in Parkinson's disease (PD), but the relationship between dopaminergic depletion and these upper limb gait changes remains unclear. Objective: We aimed to investigate the effects of dopaminergic drugs on arm swing velocity, symmetry, and coordination in PD. Methods: Forearm angular velocity was recorded in 16 PD and 17 control subjects (Controls) during free walking trials. Angular velocity amplitude of each arm, arm swing asymmetry, and maximum cross-correlation were compared between control and PD groups, and between OFF- and ON-medication states among PD subjects. Results: Compared to Controls, PD subjects in the OFF-medication state exhibited lower angular velocity amplitude of the slower- (p = 0.0018), but not faster- (p = 0.2801) swinging arm. In addition, PD subjects demonstrated increased arm swing asymmetry (p = 0.0046) and lower maximum cross-correlation (p = 0.0026). Following dopaminergic treatment, angular velocity amplitude increased in the slower- (p = 0.0182), but not faster- (p = 0.2312) swinging arm among PD subjects. Furthermore, arm swing asymmetry decreased (p = 0.0386), whereas maximum cross-correlation showed no change (p = 0.7436). Pre-drug angular velocity amplitude of the slower-swinging arm was correlated inversely with the change in arm swing asymmetry (R = −0.73824, p = 0.0011). Conclusions: This study provides quantitative evidence that reduced arm swing and symmetry in PD can be modulated by dopaminergic replacement. The lack of modulations of bilateral arm coordination suggests that additional neurotransmitters may also be involved in arm swing changes in PD. Further studies are warranted to investigate the longitudinal trajectory of arm swing dynamics throughout PD progression.

Keywords: Arm swing, dopamine, Parkinson's disease, locomotion, asymmetry, gait

DOI: 10.3233/JPD-140447

Journal: Journal of Parkinson's Disease, vol. 5, no. 1, pp. 141-150, 2015