Lateralized motor control mechanisms underlie lateralized motor deficits in early Parkinson's Disease
- 1Virginia Commonwealth University
Abstract
IntroductionParkinsons Disease (PD) motor features typically begin unilaterally, but it remains unclear whether dominant versus non-dominant side motor symptoms differentially affect lateralized aspects of fine motor control.
MethodsWe recruited 16 right-handed participants with mild, asymmetric PD (8 primarily left-side affected, 8 primarily right-side affected) and 10 age-matched controls to complete a bimanual tablet task in which one hand draws a stylus to targets (leveraging trajectory control mechanisms) while the other hand simultaneously stabilizes a stylus over a stationary target (leveraging stabilizing control mechanisms). The styli are connected via a resistance band to mimic internal forces that arise during asymmetric, bimanual activities of daily living.
ResultsBoth PD groups demonstrated preserved trajectory control in their dominant hand relative to controls (p > .072), but significantly impaired stabilizing control in their non-dominant hand (p < .022), with the largest deficits observed in the left-side PD group. Trajectory control performance significantly correlated with an overall measure of motor severity (r(14) = .69; p = .004), while stabilizing control did not (p = .56).
DiscussionThese findings suggest that left- and right-side motor symptoms in early PD produce distinct patterns of functional impairment (rather than simple contralateral analogs) that may be related to underlying lateralized motor control mechanisms. This work highlights a potential gap in standard clinical motor assessments, which may not adequately capture non-dominant side stabilizing deficits in early PD.
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BibTeX
@misc{dexheimer2026lateralized,
title = {{Lateralized motor control mechanisms underlie lateralized motor deficits in early Parkinson's Disease}},
author = {B. Dexheimer and C. Selb and J. Manning and N. Yaghoubi and A. Porreca and M. J. Barrett and P. E. Pidcoe and D. Krusienski and B. D. Berman},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.09.26362567},
url = {https://www.medrxiv.org/content/10.64898/2026.09.09.26362567v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Lateralized motor control mechanisms underlie lateralized motor deficits in early Parkinson's Disease
AU - B. Dexheimer
AU - C. Selb
AU - J. Manning
AU - N. Yaghoubi
AU - A. Porreca
AU - M. J. Barrett
AU - P. E. Pidcoe
AU - D. Krusienski
AU - B. D. Berman
PY - 2026
DA - 2026/09/09
PB - medRxiv
DO - 10.64898/2026.09.09.26362567
UR - https://www.medrxiv.org/content/10.64898/2026.09.09.26362567v1
AB - IntroductionParkinsons Disease (PD) motor features typically begin unilaterally, but it remains unclear whether dominant versus non-dominant side motor symptoms differentially affect lateralized aspects of fine motor control. MethodsWe recruited 16 right-handed participants with mild, asymmetric PD (8 primarily left-side affected, 8 primarily right-side affected) and 10 age-matched controls to complete a bimanual tablet task in which one hand draws a stylus to targets (leveraging trajectory control mechanisms) while the other hand simultaneously stabilizes a stylus over a stationary target (leveraging stabilizing control mechanisms). The styli are connected via a resistance band to mimic internal forces that arise during asymmetric, bimanual activities of daily living. ResultsBoth PD groups demonstrated preserved trajectory control in their dominant hand relative to controls (p > .072), but significantly impaired stabilizing control in their non-dominant hand (p < .022), with the largest deficits observed in the left-side PD group. Trajectory control performance significantly correlated with an overall measure of motor severity (r(14) = .69; p = .004), while stabilizing control did not (p = .56). DiscussionThese findings suggest that left- and right-side motor symptoms in early PD produce distinct patterns of functional impairment (rather than simple contralateral analogs) that may be related to underlying lateralized motor control mechanisms. This work highlights a potential gap in standard clinical motor assessments, which may not adequately capture non-dominant side stabilizing deficits in early PD.
ER -