Abstract
Clinical scales such as the Progressive Supranuclear Palsy Rating Scale (PSPRS) are standard tools for assessing disease severity in progressive supranuclear palsy (PSP). However, their use is limited by infrequent administration, observer bias, and clinic-based assessments. Objective, ecologically valid digital biomarkers offer the potential for more sensitive tracking of disease progression, reduced patient burden, and improved utility in therapeutic trials.
Clinical scales such as the Progressive Supranuclear Palsy Rating Scale (PSPRS) are standard tools for assessing disease severity in progressive supranuclear palsy (PSP). However, their use is limited by infrequent administration, observer bias, and clinic-based assessments. Objective, ecologically valid digital biomarkers offer the potential for more sensitive tracking of disease progression, reduced patient burden, and improved utility in therapeutic trials.
The objective of this study was to evaluate the feasibility and utility of multimodal digital health technologies for longitudinal monitoring of disease severity in PSP. We enrolled 43 individuals with PSP (mean age 71.3 ± 7.9 years; 21 female) across two CurePSP Centers of Care (Massachusetts General Hospital and Johns Hopkins University). Participants underwent up to 12 months of monitoring with assessments every 3 months (baseline, 3, 6, 9, and 12 months). At-home monitoring included wearable activity tracking using PAMSys™ pendant sensors and tablet-based assessments of speech, cognition, and fine motor control via the BioDigit Home™ platform. Clinical evaluations (mPSPRS) were conducted in person or remotely. Digital outcomes were compared with corresponding clinical scores.
Wearable-derived activity features correlated significantly with clinical disease severity. Total steps (R = −0.28, p = 0.0114), sit-to-stand transitions (R = −0.38, p = 0.0005), and total walking time (R = −0.29, p = 0.008) decreased with worsening mPSPRS, while step-duration variability increased (R = 0.43, p = 0.0001). Digital speech, cognitive, and fine motor metrics also demonstrated significant associations with mPSPRS scores.
In conclusion, multimodal digital biomarkers captured clinically relevant aspects of PSP progression across motor, speech, and cognitive domains. These findings support the feasibility of remote, sensor-based monitoring and highlight the potential of digital endpoints as sensitive, low-burden outcome measures for future PSP clinical studies.
