BACKGROUND
Parkinson’s disease (PD) is common movement disorder and patients with PD had multiple gait impairments, leading to increased risk of falls, and diminished quality of life. The gait measurement in patients with Parkinson’s disease (PD) is thus important for the management of PD.
OBJECTIVE
We have developed and validated a smartphone-based assessment of gait, allowing the remote gait assessment in healthy cohorts. We here aimed to test the validity of this App-based gait measurement in people with PD and explore the association between the gait metrics measured by App and the clinical and functional characteristics in PD.
METHODS
Fifty-two participants with clinically-diagnosed PD completed assessments of walking, MDS-Unified Parkinson's Disease Rating Scale III (UPDRS III), Montreal Cognitive Assessment (MoCA), Hamilton Anxiety (HAM-A) and Depression (HAM-D) rating scale tests. Participants followed multi-media instructions provided by the App to complete two 20-meter trials each of walking normally (single-task) and walking while performing a serial subtraction dual task (dual-task). The locomotion data were simultaneously collected with the App and a gold-standard system. The gait stride times (ST) and stride time variability (STV) were derived from the acceleration and angular velocity signal acquired from the internal motion sensor of the phone, and from the wearable sensor system.
RESULTS
High correlations between the ST and STV derived from the App and those from gold-standard system were observed (r=0.98~0.99, p<.0001), revealing excellent validity of the App-based gait assessment in PD. Compared to single-task, the ST (F=13.1, p=.0005) and STV (F=6.3, p=.01) in dual-task condition were significantly greater. Participants with greater STV in both conditions had greater total score of UPDRS III (r=0.37~0.39, p=.0007~.01), HAM-A (single-task: r=0.49, p=.007; dual-task: r=0.48, p=.009) and HAM-D (single-task: r=0.44, p=.01; dual-task: r=0.49, p=.009); and those with greater dual-task STV (r=0.48, p=.001) and/or dual-task cost to STV (r=0.44, p=.004) had lower MoCA score.
CONCLUSIONS
These results demonstrated that this ease-of-its-use smartphone-based gait measurement is validated and provides meaningful metrics that are associated with clinical and functional characteristics in PD.