Quantitative Digitography Measures Motor Symptoms and Disease Progression in Parkinson’s Disease

Article type: Research Article

Authors: Wilkins, Kevin B.^a | Petrucci, Matthew N.^a | Kehnemouyi, Yasmine^a | Velisar, Anca^{a; b} | Han, Katie^a | Orthlieb, Gerrit^a | Trager, Megan H.^{a; c} | O’Day, Johanna J.^{a; d} | Aditham, Sudeep^a | Bronte-Stewart, Helen^{a; e; *}

Affiliations: [a] Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA | [b] The Smith-Kettlewell Eye Research Institute, San Francisco, CA, USA | [c] Columbia University College of Physicians and Surgeons, New York City, NY, USA | [d] Department of Bioengineering, Stanford University, Stanford, CA, USA | [e] Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA

Correspondence: [*] Correspondence to: Helen Bronte-Stewart, MD, MSE, Department of Neurology and Neurological Sciences, Stanford Movement Disorders Center (SMDC), Rm 254A, 453 Quarry Rd, Stanford University School of Medicine, Stanford, CA 94304, USA. Tel.: +1 650 723 2116; Fax: +1 650 725 7459; E-mail: [email protected].

Abstract: Background:Assessment of motor signs in Parkinson’s disease (PD) requires an in-person examination. However, 50% of people with PD do not have access to a neurologist. Wearable sensors can provide remote measures of some motor signs but require continuous monitoring for several days. A major unmet need is reliable metrics of all cardinal motor signs, including rigidity, from a simple short active task that can be performed remotely or in the clinic. Objective:Investigate whether thirty seconds of repetitive alternating finger tapping (RAFT) on a portable quantitative digitography (QDG) device, which measures amplitude and timing, produces reliable metrics of all cardinal motor signs in PD. Methods:Ninety-six individuals with PD and forty-two healthy controls performed a thirty-second QDG-RAFT task and clinical motor assessment. Eighteen individuals were followed longitudinally with repeated assessments for an average of three years and up to six years. Results:QDG-RAFT metrics showed differences between PD and controls and provided correlated metrics for total motor disability (MDS-UPDRS III) and for rigidity, bradykinesia, tremor, gait impairment, and freezing of gait (FOG). Additionally, QDG-RAFT tracked disease progression over several years off therapy and showed differences between akinetic-rigid and tremor-dominant phenotypes, as well as people with and without FOG. Conclusions:QDG is a reliable technology, which could be used in the clinic or remotely. This could improve access to care, allow complex remote disease management based on data received in real time, and accurate monitoring of disease progression over time in PD. QDG-RAFT also provides the comprehensive motor metrics needed for therapeutic trials.

Keywords: Alternating finger tapping, cardinal motor signs, freezing of gait, keyboard, Parkinson’s disease, phenotype, remote measurement, rigidity, Unified Parkinson’s Disease Rating Scale, wearables

DOI: 10.3233/JPD-223264

Journal: Journal of Parkinson's Disease, vol. Pre-press, no. Pre-press, pp. 1-12, 2022