Turning heads: does head motion during turning in people with Parkinson’s disease correlate with clinical measures?

Introduction: Turning is essential to mobility, constituting 35-45% of all daily steps. Falls during turning are more severe with 7.9x greater risk of hip fracture. Reduced quality of turning has been observed in people with Parkinson’s disease (PwP). Findings suggest head and trunk control during turning are different in PwP compared to controls, however it is unclear how this relates to clinical measures. Methods: 36 PwP completed an intermittent walking task with 180 degree turns (ICICLE-Gait). An inertial measurement unit attached to the head evaluated head rotations (>30 degrees). Turning features were extracted using a validated algorithm. Spatiotemporal (duration, velocity) and signal-based features reflecting movement intensity (root mean square [RMS] in the mediolateral [ML], anterior-posterior [AP] and vertical [VT] planes from the gyroscope) were extracted. Relationships between turning and clinical measures (Activities of Balance confidence (ABC), Mini Mental State Exam (MMSE), Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) II and III, Levodopa Equivalent Daily Dose (LEDD)) were evaluated using Spearman’s rho. Results: There were 2/6 spatiotemporal and 13/25 signal features with weak-to-moderate correlations with clinical measures. Lower cognition and reduced balance confidence were associated with slower head rotations (rho=0.416-465, p<.05) and lower head movement intensity (lower rms: rho=0.340, p<0.05). higher disease severity (higher mds updrs-ii, iii scores) was associated with slower rotations (rho="-0.322:-0.436," p<0.05) increased ledd greater conclusion: rotation velocity are important features of turning that correlate clinical outcomes relevant in parkinson’s. places a demand on sensory, cognitive motor systems which affected pwp. further analysis will explore whether correlations exist for other segments during (i.e. torso), (such as axial rigidity), gait.