Effects of activity-oriented physiotherapy with and without eye movement training on dynamic balance, functional mobility, and eye movements in patients with Parkinson's disease: An assessor-blinded randomised controlled pilot trial

Abstract

Objectives: To describe changes in balance, walking speed, functional mobility, and eye movements following an activity-oriented physiotherapy (AOPT) or its combination with eye movement training (AOPT-E) in patients with Parkinson's disease (PD). To explore the feasibility of a full-scale randomised controlled trial (RCT).

Methods: Using an assessor-blinded pilot RCT, 25 patients with PD were allocated to either AOPT or AOPT-E. Supervised interventions were performed 30 minutes, 4x/weekly, for 4 weeks, alongside inpatient rehabilitation. Outcomes were assessed at baseline and post-intervention, including dynamic balance, walking speed, functional and dual-task mobility, ability to safely balance, health-related quality of life (HRQoL), depression, and eye movements (number/duration of fixations) using a mobile eye tracker. Freezing of gait (FOG), and falls-related self-efficacy were assessed at baseline, post-intervention, and 4-week follow-up. Effect sizes of 0.10 were considered weak, 0.30 moderate, and ≥0.50 strong. Feasibility was assessed using predefined criteria: recruitment, retention and adherence rates, adverse events, falls, and post-intervention acceptability using qualitative interviews.

Results: Improvements were observed in dynamic balance (effect size r = 0.216-0.427), walking speed (r = 0.165), functional and dual-task mobility (r = 0.306-0.413), ability to safely balance (r = 0.247), HRQoL (r = 0.024-0.650), and depression (r = 0.403). Falls-related self-efficacy (r = 0.621) and FOG (r = 0.248) showed varied improvements, partly sustained at follow-up. Eye movement improvements were observed after AOPT-E only. Feasibility analysis revealed that recruitment was below target, with less than two patients recruited per month due to COVID-19 restrictions. Feasibility targets were met, with a retention rate of 96% (95% confidence interval [CI]: 77.68-99.79) and a 98.18% (95% CI: 96.12-99.20) adherence rate, exceeding the targets of 80% and 75%, respectively. One adverse event unrelated to the study intervention confirmed intervention safety, and interview data indicated high intervention acceptability.

Conclusions: AOPT-E and AOPT appeared to be effective in patients with PD. Feasibility of a larger RCT was confirmed and is needed to validate results.

Fig 1. CONSORT flow diagram.

DBS: deep brain stimulation; H&Y: Hoehn & Yahr scale.

Fig 2. Effect of interventions on dynamic balance during walking.

Box plots represent changes in dynamic balance during walking in the AOPT-E (left) and AOPT (right) groups, assessed by the Functional Gait Assessment (FGA). Medians are shown by lines in the centre of the boxes, the interquartile ranges are indicated by the boxes and ranges by the whiskers. Each dot represents one participant. BL: baseline, PI: post-intervention.

Fig 3. Comparison of eye movements during pivot turning while walking between the two groups.

Bubble plots of eye movements during turning of the AOPT-E and AOPT groups: minimum duration of fixations in milliseconds at baseline and at post-intervention (A); maximum duration of fixations in milliseconds at baseline and post-intervention (B), and number of fixations at baseline and post-intervention (C). Darker colours represent a longer duration of fixations. AOPT-E: activity-oriented physiotherapy plus eye movement training; AOPT: activity-oriented physiotherapy; BL: baseline; FGA: Functional Gait Assessment; PI: post-intervention.

Fig 4. Comparison of eye movements during stepping over an obstacle between the two groups.

Bubble plots of eye movements during stepping over an obstacle of the AOPT-E and AOPT groups: the minimum duration of fixations in milliseconds at baseline and at post-intervention (A); maximum duration of fixations in milliseconds at baseline and at post-intervention (B); and number of fixations at baseline and at post-intervention (C). Darker colours represent a longer duration of fixations and greater number of fixations respectively. Stepping over the obstacle is visualised by the action. AOPT-E: activity-oriented physiotherapy plus eye movement training; AOPT: activity-oriented physiotherapy; bef.: before; beh.: behind; BL: baseline; FGA: Functional Gait Assessment; obj.: object; PI: post-intervention.

Fig 5. Effect of interventions on walking speed.

Box plots represent changes in walking speed in the AOPT-E (left) and AOPT (right) groups, assessed by the 10-Metre Walk Test (10MWT). Medians are shown by lines in the centre of the boxes, the interquartile ranges are indicated by the boxes and ranges by the whiskers. Each dot represents one participant. BL: baseline, PI: post-intervention.

Fig 6. Effect of interventions on balance and functional mobility.

Box plots represent changes in the ability to safely balance (Berg Balance Scale, BBS), dynamic balance (Four Square Step Test, FSST), functional mobility (Timed Up and Go, TUG), and functional mobility with a motor task (Timed Up and Go manual, TUGman) in the AOPT-E (left) and AOPT (right) groups. Medians are shown by lines in the centre of the boxes, the interquartile ranges are indicated by the boxes and ranges by the whiskers. Each dot represents one participant. BL: baseline, PI: post-intervention.

Fig 7. Gaze plots of two selected participants.

Using the wall poster, gaze plots of participants illustrate normal eye movements in a patient with Hoehn & Yahr stage 1 (A) and dysfunctional eye movements in a patient with Hoehn & Yahr stage 3 (low accuracy, abnormally frequent and substantial square wave jerks alongside short duration of fixation on target dots). Larger circles indicate a longer duration of fixation on the respective dots.