Category: Parkinson's Disease (Other)
Objective: To define the motor progression of motor prodromes using two remote keyboard tapping tests (BRAIN and DFT tests) and two remote standardised clinical rating scales (MDS-UPDRS Part II and III (excluding rigidity and postural stability) in Isolated REM Sleep Behaviour Disorder (iRBD). The keyboard test parameters including kinesia score (KS, number of alternate taps per task), akinesia time (AT, mean dwell-time on each tap in ms), and incoordination score (IS, the variance of traveling time between taps) were analysed on average over 3-time points between 2021-2025.
Background: iRBD is characterised by loss of REM atonia by video-polysomnography (v-PSG). Individuals with iRBD have slow and arrhythmic keyboard tapping using the BRadykinesia Akinesia INcoordination (BRAIN) test and the Distal Finger Tapping (DFT) which are validated online tests used to assess motor dysfunction in Parkinson’s disease1-3.
Method: This longitudinal study compares the motor trajectory of individuals with iRBD with and without subthreshold parkinsonism (SP) (MDS-UPDRS-III >6, excluding action tremor). Using linear mixed effects models, we evaluated the accuracy of objective tools (BRAIN and DFT tests) in detecting affected individuals.
Results: Eighteen individuals with PSG-confirmed iRBD, with SP (n=5; 75% male; mean age 71 y., SD 8.68) and without SP (n=10; 100% male; mean age 64 y., SD 8.04), were assessed over a mean of 3.66 years (SD 0.55). Three participants were diagnosed with PD and excluded from analysis. The differences in sex and age distribution between groups were not significant (p=0.71 and p=0.18, respectively). DFT-AT, BRAIN-KS and IS show significantly worsening motor decline over time 17.06 (95% CI: 9.13 – 24.99, p = <0.001, SE = 4.05); -3.29 (95% CI: -6.04 – -0.54, p = 0.03, SE = 1.40); 15229.84 (95% CI: 1408.39 – 29051.28, p = 0.0392, SE = 7051.76) respectively. DFT KS, IS and BRAIN AT suggest a trend of worsening motor function, but it is not significant (p = 0.08, p = 0.13, p = 0.51 respectively). Remote MDS-UPDRS-III and MDS-UPDRS-II did not statistically change over time: -2.11; p = 0.27; -1.26; p = 0.27) respectively.
Conclusion: BRAIN-KS/IS and DFT-AT tests detect early motor decline in iRBD more effectively (AT and IS increase and KS decreases) than remote MDS-UPDRS-III and MDS-UPDRS-II. These highlight the value of remote digital assessments for early monitoring of motor impairment in participants with iRBD.
References: 1. Simonet C, Pérez-Carbonell L, Galmés-Ordinas MA, Huxford BFR, Chohan H, Gill A, Leschziner G, Lees AJ, Schrag A, Noyce AJ. The Motor Dysfunction Seen in Isolated REM Sleep Behavior Disorder. Mov Disord. 2024 Jun;39(6):1054-1059. doi: 10.1002/mds.29779. Epub 2024 Mar 12. PMID: 38470080.
2. Noyce AJ, Nagy A, Acharya S, Hadavi S, Bestwick JP, Fearnley J, Lees AJ, Giovannoni G. Bradykinesia-akinesia incoordination test: validating an online keyboard test of upper limb function. PLoS One. 2014 Apr 29;9(4):e96260.
3. Akram N, Li H, Ben-Joseph A, Budu C, Gallagher DA, Bestwick JP,et al. Developing and assessing a new web-based tapping test formeasuring distal movement in Parkinson’s disease: a distal fingertapping test. Sci Rep 2022;12:386
To cite this abstract in AMA style:
M. Patyjewicz, A. Zirra, B. Kansu, H. Chohan, L. Pérez-Carbonell, A. Noyce, C. Simonet. Promising Remote Markers of Motor Progression in Isolated REM Sleep Behaviour Disorder [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/promising-remote-markers-of-motor-progression-in-isolated-rem-sleep-behaviour-disorder/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/promising-remote-markers-of-motor-progression-in-isolated-rem-sleep-behaviour-disorder/