Freezing of gait in Parkinson’s disease: rehabilitation and measurement

This thesis presents three studies: (1) a systematic review with meta-analyses that evaluates the effects of rehabilitation interventions on freezing of gait in people with Parkinson’s disease; (2) a pilot trial that examines the feasibility and acceptability of a video self-modelling intervention to address freezing of gait; and (3) a study that explores the reliability, validity, and usability of the Ziegler test to measure freezing of gait severity. In study 1, results from meta-analyses show a small effect of physiotherapy/exercise on reducing freezing of gait post-intervention (Hedges’ g=-0.26, 95% CI -0.38 to -0.14), consistent with previous reviews. However, the robust methodology used in study 1 suggests cautious interpretation as the certainty of the evidence is very low and intervention effects are unlikely to be clinically meaningful. It is likely that a comprehensive assessment of freezing of gait triggers and prescription of personalised interventions that is sustained over time will be most effective at addressing freezing of gait. In study 2, evaluation of personalised video self-modelling (delivered via a virtual reality headset) plus physical practice of movement strategies, was shown to be both feasible and acceptable, with 90% retention, 84% adherence to video viewing and most reporting they would use the intervention again. In study 3, the Ziegler test was shown to be a reliable (ICC2,1=0.80; ICC3,1=0.91) and valid freezing of gait severity measure when used by physiotherapists in real time. The Ziegler test duration may also be used as a proxy measure for freezing of gait severity. Taken together, these results help researchers and clinicians determine effective personalised interventions to reduce freezing of gait and improve measurement of freezing of gait severity by using quantitative tools. Reducing freezing of gait could improve mobility, reduce fall risk, and increase health-related quality of life in people with Parkinson’s disease