Postural sway and effect of levodopa in early Parkinson's disease

Objective: To characterize postural stability control and levodopa responsiveness in early Parkinson's disease (PD). Methods: Postural sway was studied during quiet stance in ten patients within six years of PD onset, both before (OFF) and after (ON) regular oral levodopa dosing. Postural sway was recorded using a force platform during 30 sec with eyes open, and six dependent variables were examined. Results: Mild baseline subclinical changes in postural sway were recorded in our patients. Clear benefit was observed in five out of six characteristics (mean sway, transversal sway, sagittal sway, sway intensity, and sway area) in the ON condition. Conclusion: Postural control mechanisms are affected early in PD and modulated by dopamine.