Use of a Smartphone to Gather Parkinson's Disease Neurological Vital Signs during the COVID-19 Pandemic

Abstract

Introduction: To overcome travel restrictions during the COVID-19 pandemic, consumer-based technology was rapidly deployed to the smartphones of individuals with Parkinson's disease (PD) participating in a 12-month exercise trial. The aim of the project was to determine the feasibility of utilizing a combined synchronous and asynchronous self-administered smartphone application to characterize PD symptoms.

Methods: A synchronous video virtual visit was completed for the administration of virtual Movement Disorder Society-Unified Parkinson's Disease Rating Scale III (vMDS-UPDRS III). Participants asynchronously completed a mobile application consisting of a measure of upper extremity bradykinesia (Finger Tapping Test) and information processing.

Results: Twenty-three individuals completed the assessments. The mean vMDS-UPDRS III was 23.65 ± 8.56 points. On average, the number of taps was significantly greater for the less affected limb, 97.96 ± 17.77 taps, compared to the more affected, 89.33 ± 18.66 taps (p = 0.025) with a significantly greater number of freezing episodes for the more affected limb (p < 0.05). Correlation analyses indicated the number of errors and the number of freezing episodes were significantly related to clinical ratings of vMDS-UPDRS III bradykinesia (Rho = 0.44, p < 0.01; R = 0.43, p < 0.01, resp.) and finger tapping performance (Rho = 0.31, p = 0.03; Rho = 0.32, p = 0.03, resp.). Discussion. The objective characterization of bradykinesia, akinesia, and nonmotor function and their relationship with clinical disease metrics indicate smartphone technology provides a remote method of characterizing important aspects of PD performance. While theoretical and position papers have been published on the potential of telemedicine to aid in the management of PD, this report translates the theory into a viable reality.

Figure 1

(a) Screenshot of the display from the FTT application on an iPhone. Representative data from one participant performing FTT test with their less affected (b) and more affected (c) hands. Each bar represents the time duration (ms) between the onset of consecutive taps (intertap interval) with the left target shown in red and the right one in green. Errors were defined as consecutive taps on the same target. Intertap intervals greater than 500 msec were classified as a freeze (blue line denotes threshold for a freeze). The more affected side performed a lower number of total taps compared to the less affected hand (95 vs. 64 taps, resp.), with a longer average intertap interval (461.6 vs. 315.1 ms, resp.), committed an increased number of errors (1 vs. 0 errors, respectively), and exhibited a greater number of freezing episodes (11 vs. 0, resp.).

Figure 2

Finger Tapping Test measures: (a) the number of taps and (b) the number of errors were significantly related to upper extremity (UE) PD severity score measured by the vMDS-UPDRS III. Timed up and go trial times (c, d) were significantly related to total vMDS-UPDRS-III score, and clinical measures of postural and gait deficits (PIGD) measured by the vMDS-UPDRS III, Spearman rank correlation analyses, p < 0.05 for a–d.