Progressive Supranuclear Palsy (PSP) is a rare neurodegenerative disease characterised by motor dysfunction, such as axial rigidity and frequent falls. Falls can increase in incidence along disease progression, and occur especially when patients turn, possibly due to assumed vestibular-mediated postural control impairments. Thus, turn-related parameters could potentially serve as PSP progression biomarkers. 

Nevertheless, clinical rating scales, constituting the gold standard for tracking PSP progression, are subjective and do not specifically assess turns. Advances in digital technology now provide the ability to reliably collect objective and accurate turn-related parameters. As such, the Oxford Quantification in Parkinsonism study used Inertial Measurement Unit sensors to track the evolution of turn-related parameters in PSP patients performing 2 clinical tasks across 12 months, with hospital visits taking place every 3 months. Strong correlations between data from both tasks suggested both were equally suitable for tracking progression. The task in which patients executed a higher number of turns was deemed as more informative and was carried on to analysis. Several turn-related parameters from this task, namely Mean Turn Velocity, Mean Turn Duration, and the Mean Number of Steps in Turn, were found to reflect PSP progression 9 months and/or 12 months into the study. In comparison, only 1 of 2 clinical rating scales, the Unified Parkinson’s Disease Rating Scale, reflected PSP progression. Thus, sensor-generated turn-related parameters could serve as objective and specific biomarkers for PSP progression, which are essential to accurately assess patient responses in clinical trials