title: Effect of dopaminergic medication on postural sway in advanced Parkinson's disease.
abstract: BACKGROUND
  The effect of dopaminergic therapy on balance in Parkinson's disease (PD) remains unclear, including previous studies that excluded the effect of dyskinesias or other involuntary movements on postural sway. Additionally, medication's effects may differ between fallers and non-fallers. In this study, the authors quantify the effect of dopaminergic medication on postural balance (sway) in advanced PD, with and without dyskinesias, and consider the patient's history of falls.
  
  
  METHODS
  In 24 patients with advanced idiopathic PD, postural balance was measured using a strain-gage force platform. Before and after taking dopaminergic medication, the patient's postural sway was measured at 30-s intervals to determine sway length (SL) and sway area (SA). Data analysis included the presence of dyskinesias during "ON" medication condition and history of previous falls.
  
  
  RESULTS
  No significant changes occurred in SL or SA with dopaminergic treatment for fallers without dyskinesias or non-fallers with dyskinesias. However, after dopaminergic treatment, SL and SA were 37.8 and 45% lower, respectively, in non-fallers without dyskinesias (indicating better balance) and were 87.4 and 162.8% higher, respectively, in fallers with dyskinesias (indicating poorer balance). In the ON-medication condition, SL and SA were larger in patients with dyskinesias when compared with patients without dyskinesias; SL was larger in fallers than non-fallers in both groups with or without dyskinesias.
  
  
  CONCLUSIONS
  Dopaminergic medication effects on postural sway could be a predictive factor for fall risk in PD patients with and without dyskinesias: specifically, decreased sway could indicate minimal fall risk whereas no change or increased postural sway could indicate a high risk.
authors.affiliation: Department of Neurology, University of Cincinnati College of Medicine , Cincinnati, OH , USA ; Gardner Center for Parkinson's and Movement Disorders, University of Cincinnati Neuroscience Institute , Cincinnati, OH , USA ; Veterans Affairs Medical Center , Cincinnati, OH , USA.
authors.forename: Fredy J
authors.initials: FJ
authors.lastname: Revilla
authors.affiliation: Department of Neurology, University of Cincinnati College of Medicine , Cincinnati, OH , USA.
authors.forename: Travis R
authors.initials: TR
authors.lastname: Larsh
authors.affiliation: Biomechanics-Ergonomics Research Laboratory, Department of Environmental Health, University of Cincinnati College of Medicine , Cincinnati, OH , USA.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Mani
authors.affiliation: Department of Neurology, University of Cincinnati College of Medicine , Cincinnati, OH , USA ; Gardner Center for Parkinson's and Movement Disorders, University of Cincinnati Neuroscience Institute , Cincinnati, OH , USA.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Duker
authors.affiliation: Biomechanics-Ergonomics Research Laboratory, Department of Environmental Health, University of Cincinnati College of Medicine , Cincinnati, OH , USA.
authors.forename: Cyndy
authors.initials: C
authors.lastname: Cox
authors.affiliation: Department of Environmental Health, Division of Epidemiology and Biostatistics, University of Cincinnati College of Medicine , Cincinnati, OH , USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Succop
authors.affiliation: Department of Neurology, University of Cincinnati College of Medicine , Cincinnati, OH , USA.
authors.forename: Maureen
authors.initials: M
authors.lastname: Gartner
authors.affiliation: Department of Internal Medicine, Virginia Commonwealth University Medical Center , Richmond, VA , USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Jarrin Tejada
authors.affiliation: Biomechanics-Ergonomics Research Laboratory, Department of Environmental Health, University of Cincinnati College of Medicine , Cincinnati, OH , USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Bhattacharya
keywords: Parkinson’s disease; balance; dopaminergic; dyskinesia; fall; levodopa; postural; sway