Data from: Smartphone motor testing to distinguish idiopathic REM sleep behavior disorder, controls, and PD

Objective: We sought to identify motor features that would allow the
delineation of individuals with sleep study-confirmed idiopathic rapid eye
movement sleep behaviour disorder (iRBD) from controls and Parkinson’s
disease (PD) using a customised smartphone application. Methods: 334 PD,
104 iRBD, and 84 control participants performed seven tasks to evaluate
voice, balance, gait, finger tapping, reaction time, rest tremor, and
postural tremor. Smartphone recordings were collected both in clinic and
at home under non-controlled conditions over several days. All
participants underwent detailed parallel in-clinic assessments. Using only
the smartphone sensor recordings, we sought to: (1) discriminate whether
the participant had iRBD or PD and, (2) identify which of the above seven
motor tasks were most salient in distinguishing groups. Results:
Statistically significant differences based on these seven tasks were
observed between the three groups. For the three pairwise discriminatory
comparisons: (1) Controls versus iRBD, (2) Controls versus PD, and (3)
iRBD versus PD, mean sensitivity and specificity values ranged from 84.6%
to 91.9%. Postural tremor, rest tremor, and voice were the most
discriminatory tasks overall, while reaction time was least
discriminatory. Conclusions: Prodromal forms of PD include the sleep
disorder iRBD, where subtle motor impairment can be detected using
clinician based rating scales (e.g UPDRS), which may lack the sensitivity
to detect and track granular change. Consumer grade smartphones can be
used not only to accurately separate iRBD from controls, but also iRBD
from PD participants, providing growing consensus for the utility of
digital biomarkers in early and prodromal PD.