300 Section - Impact of Modified Movement Sensations on the Sense of Agency in Early-Stage Parkinson’s Disease

Objectives : In Parkinson’s disease (PD), motor and non-motor symptoms often appear gradually before diagnosis, and many individuals in Japan first visit other medical departments, delaying early intervention. Early non-motor signs and subtle bodily changes may create movement heaviness and a reduced sense of agency (SoA), affecting daily life even before clear motor symptoms emerge. This study explored how altered movement sensations and non-motor experiences near the time of diagnosis influence the sense of agency in early-stage PD.

Design: Four individuals with Parkinson’s disease (HY stage I) participated in this qualitative study. Semi-structured interviews explored their perceptions of bodily sensations and movement changes before and after diagnosis. Participants reported early sensory changes, movement heaviness, and difficulties initiating or controlling actions, and how these affected their sense of agency. Using a COPM-based format, the interviews were analyzed qualitatively to identify themes linking altered movement sensations with daily functioning and agency.

Results: Participants reported that daily fluctuations in motor symptoms and mismatches between intended and actual movement created anxiety and lowered their sense of agency. Non-motor symptoms such as constipation had less impact on SoA than these temporal motor variations. Those who recognized their own symptom fluctuations and used self-regulation strategies—such as adjusting activity timing or practicing relaxation—reported greater daily satisfaction. These results suggest that awareness and management of one’s bodily state help support a positive sense of agency and emotional stability.

Conclusion: Frequent “out-of-control” moments and mismatches between intention and movement appear to reduce the sense of agency and increase psychological distress in early Parkinson’s disease. Even subtle disruptions in bodily control may undermine confidence in daily actions. Early support that strengthens self-management skills and body awareness may help preserve agency. Participants also reported feeling better after exercise, highlighting the importance of ongoing, appropriate physical activity for maintaining agency, emotional stability, and overall well-being.