Effects of dopaminergic therapy on locomotor adaptation and adaptive learning in persons with Parkinson's disease.
Persons with Parkinson's disease (PD) are characterized by multifactorial gait deficits, though the factors which influence the abilities of persons with PD to adapt and store new gait patterns are unclear. The purpose of this study was to investigate the effects of dopaminergic therapy on the abilities of persons with PD to adapt and store gait parameters during split-belt treadmill (SBT) walking. Ten participants with idiopathic PD who were being treated with stable doses of orally-administered dopaminergic therapy participated. All participants performed two randomized testing sessions on separate days: once while optimally-medicated (ON meds) and once after 12-h withdrawal from dopaminergic medication (OFF meds). During each session, locomotor adaptation was investigated as the participants walked on a SBT for 10 min while the belts moved at a 2:1 speed ratio. We assessed locomotor adaptive learning by quantifying: (1) aftereffects during de-adaptation (once the belts returned to tied speeds immediately following SBT walking) and (2) savings during re-adaptation (as the participants repeated the same SBT walking task after washout of aftereffects following the initial SBT task). The withholding of dopaminergic medication diminished step length aftereffects significantly during de-adaptation. However, both locomotor adaptation and savings were unaffected by levodopa. These findings suggest that dopaminergic pathways influence aftereffect storage but do not influence locomotor adaptation or savings within a single session of SBT walking. It appears important that persons with PD should be optimally-medicated if walking on the SBT as gait rehabilitation.
Kennedy Krieger Institute, Baltimore, MD, United States; Department of Neuroscience, The Johns Hopkins University School of Medicine, United States. Electronic address: rroemmi1@jhmi.edu.
Ryan T
RT
Roemmich
Center for Movement Disorders and Neurorestoration, University of Florida, United States; Department of Neurology, University of Florida, United States.
Nawaz
N
Hack
Center for Movement Disorders and Neurorestoration, University of Florida, United States; Department of Neurology, University of Florida, United States.
Umer
U
Akbar
Center for Movement Disorders and Neurorestoration, University of Florida, United States; Department of Applied Physiology and Kinesiology, University of Florida, United States.
Chris J
CJ
Hass
D000222:Adaptation, Physiological / Q000187:drug effects* / Q000502:physiology; D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007858:Learning / Q000187:drug effects* / Q000502:physiology; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology; D016138:Walking / Q000502:physiology
D000978:Antiparkinson Agents; D007980:Levodopa
Adaptation; Dopamine; Motor learning; Parkinson's disease; Split-belt treadmill