Tackling anxiety- and stress-related freezing of gait in people with Parkinson’s disease (TACKLING-FOG): study protocol for a randomized controlled trial

Freezing of gait (FOG) is a common and disabling symptom in people with Parkinson’s Disease (PD), characterized by paroxysmal episodes where there is an inability to step effectively, despite attempting to do so. Anxiety and stress exacerbate FOG, particularly in situations where people with FOG anticipate not being in control of their movements. Some people with PD use compensatory strategies that target anxiety and stress to improve FOG. However, tailored strategies to ameliorate anxiety- and stress-related FOG have never been evaluated in a systematic manner. TACKLING-FOG aims to evaluate the effectiveness of a novel 4-week Managing-the-Mental-State-intervention in reducing FOG-related anxiety and stress, in order to improve FOG. We also aim to identify the key determinants influencing the response to the intervention. This study is a randomized controlled trial (RCT) with a waitlist control group. Forty participants with PD who experience anxiety- or stress-related FOG will be included. All participants receive a baseline measurement and are subsequently randomized to the intervention or control group in a 1:1 ratio. The intervention group immediately receives 4 weekly sessions of the Managing-the-Mental-State-intervention, whereas the control group enters a waitlist period. Afterwards, both groups are reassessed. Next, the intervention group enters a 10-week follow-up period, while the control group receives the intervention, is re-assessed, and enters the follow-up period. Both groups receive a final measurement at the end of the follow-up. The primary outcome is the percentage of time frozen during a home-based walking course that includes self-selected FOG ‘hotspots’. Secondary outcomes involve the percentage of time frozen during the same trajectory under elevated-stress conditions and during a standardized FOG-provoking protocol. Additionally, heart rate is collected as a physiological marker of stress and anxiety, and questionnaires are administered to assess domains that may improve in response to the intervention, including anxiety, quality of life, and self-esteem. TACKLING-FOG will be the first RCT to examine the use of tailor-made behavioral strategies to tackle anxiety- and stress-related FOG in people with PD.