Recuperation of slow walking in de novo Parkinson's disease is more closely associated with increased cadence, rather than with expanded stride length

Introduction Gait characteristics in the early stages of Parkinson's disease (PD) have been less investigated so far. Moreover, the levodopa effect on gait in early PD remains to be further elucidated. We prospectively designed the study to examine gait dynamics and effect of dopaminergic treatment in patients with de novo PD. Methods Spatiotemporal parameters were measured in healthy controls and drug naïve patients with PD, using computerized analysis with GAITRite system during usual gait. In PD group, motor symptoms and gait parameters were examined in both drug naive and levodopa 100 mg trial conditions. Results Twenty four de novo PD patients and 27 healthy controls (matched for age, sex, and height) were selected for the study. Compared with the controls, patients with de novo PD showed the decrease in stride length, in both Med-OFF and Med-ON conditions. Notably, drug naïve patients with PD demonstrated slow walking velocity, whereas those with levodopa administration exhibited the increase of cadence by shortening stride time, which resulted in the improvement of gait speed. In addition, the stride length (gait hypokinesia) correlated with postural instability and gait difficulty subscore, but not with tremor, rigidity, bradykinesia, or total motor score. Conclusion As a compensatory mechanism of slow walking, we found that the increment in cadence (frequency) is more important than the increment in stride length (amplitude) in gait dynamics in de novo PD. Additionally, the results may indicate that gait hypokinesia in PD could be regarded as one of axial symptoms.