Gait variability in Parkinson's disease: influence of walking speed and dopaminergic treatment

Objectives: To study the effects of levodopa and walking speed on gait variability in individuals with Parkinson's disease (PD). Methods: Thirty-three individuals with PD were studied. Their mean age was 70.61 +/- 9.23 year. The average time since diagnosis was 9.65 +/- 5.80 year. Gait variability was studied while 'OFF' and 'ON' dopaminergic medication when the subjects walked at their usual and fastest speeds. Results: Variability of step time, double support time, stride length and stride velocity decreased significantly (P=0.037; P=0.037; P=0.022; P=0.043, respectively) after dopaminergic treatment. When subjects increased walking speed, the variability of stride length and stride velocity decreased significantly (P=0.038 and P=0.004, respectively) both while 'OFF' and 'ON' levodopa. Increasing walking speed did not change the variability of step time and double support time regardless of medication status. Conclusions: Levodopa decreased gait variability in persons with PD. Stride length and stride velocity variability appeared to be speed dependent parameters, whereas, the variability of step time and double support time appeared to be speed independent measures. Levodopa had positive effects on gait stability in PD.