World Parkinson Congress edition:2 location:Glasgow, Scotland date:September 28 - October 2010
Objective: To investigate the effect of unilateral cueing on turning and freezing of gait (FOG) in Parkinson’s disease and explore the impact of disease dominance on these effects.
Background: Freezers (FRs) increase their cadence during turning compared to non-freezers (nFRs)1 which can result in FOG. Cueing at -10% of preferred cadence can improve normal gait in FR2, but the influence on turning remains unknown.
Methods: 12 FR and 11 nFR were matched for age, leg length, disease severity, duration and amount of disease-asymmetry. Patients were asked to turn 180° left and right during baseline-condition. They were then randomly exposed to cueing of the disease-dominant and non-dominant side (calculated by UPDRS-score differences) at -10% of preferred stride frequency. After removing the cues, gait tests were repeated to determine the carry-over effects of cues. Turn duration, number of steps, cadence and amount of FOG-trials were registered by an 8 camera VICON 3D motion analysis system for each turn side and condition. ANOVA for repeated measures was used to analyze the data. The influence of cueing on FOG was calculated using Chi-square statistics.
Results: 4 FRs froze during baseline testing, resulting in 14 FOG-trials. No FOG occurred during cueing (p<0.01). During the carry-over trials after cueing, 14 FOG-trials were found. After removing the FOG-trials from the data, FRs took longer, used more steps and had a higher cadence to complete the turn compared to nFRs. During cueing, both groups decreased their cadence (p<0.01) and overall more steps were needed to turn to the disease-dominant side (p<0.05). However, a turn*condition*group effect was found for turn duration (p<0.05) This indicated that NFRs turned more efficiently in response to cueing, by reducing their cadence within the same turn duration in all conditions. In contrast, FRs benefited only from cueing, when cueing the disease dominant side while turning towards that side.
Conclusion: Unilateral cueing reduces the occurrence of FOG during turning, but this effect is not maintained when the cues are taken away. Although FRs and nFRs had comparable disease characteristics, only nFRs benefit from adjusting their cadence to the slower cueing pace to both turning sides. FRs respond selectively to cueing, indicating that cueing the disease-dominant side when turning towards the same side is effective only.
1. Spildooren J et al. Mov Disord. Submitted.
2. Willems AM et al. Disability and rehabilitation. 2006