Balance and gait in Parkinson’s disease : from perceptions to performance

Abstract: The overall aim of this thesis was to explore perceptions and performance of balance and gait in people with Parkinson’s disease (PwPD), and to evaluate both the current evidence for exercise-induced neuroplasticity and the feasibility of investigating exercise-induced neuroplastic changes among PwPD. This thesis includes four papers of different designs; a qualitative interview study (paper I), a systematic review and meta-analysis (paper II), a pilot RCT (paper III) and a crosssectional study (paper IV). Participants in papers I, III & IV were recruited through advertisement in newspapers and through the Parkinson association in Stockholm (sample sizes n=18, n=13 and n=93, respectively), whereas paper II selected studies from database searches (included studies n=13, total participant sample n=213). Five themes emerged from the qualitative content analysis of the interviews, the underlying patterns of which formed the overarching theme “Focus and determination to regain control over shifting balance”. In paper II, the narrative synthesis revealed that a majority of the studies indicated that exercise can possibly induce positive neuroplastic changes in PwPD, but the evidence according to the GRADE analysis was very low. In paper III we found that a proposed design to explore associations between changes in behavioral outcomes and neuroplasticity after ten weeks of the HiBalance training was feasible and acceptable given a few modifications ahead of the RCT. Finally paper IV showed that people with mild to moderate PD exhibited impaired performance across most domains of gait when simultaneously having to concentrate on a cognitive task (dual tasking). Impaired cognitive function was associated with higher costs on gait, as well as a tendency to use a posture-second prioritization in which the cognitive task was prioritized over walking. Balance was perceived as both bodily equilibrium and a mind-body interplay. The meaning of balance was described through concepts of control and the ability to control one’s body in everyday life. Regarding exercise-induced neuroplasticity in PD, published studies showed promising results, but more high-quality RCTs, using scientifically sound methodology are needed in order to drive this research field forward. Our proposed RCT design to evaluate neuroplastic changes after the HiBalance training was feasible, but needed strengthening regarding blinding procedures, the MRI paradigm and the dual task gait assessment. Walking while simultaneously concentrating on a cognitive task impaired performance on both tasks, especially among those with cognitive impairment. These findings provide preliminary evidence to suggest that dual task training and assessment should be planned and instructed differently according to cognitive status in PwPD.