Objective: First, to determine the utility of ‘rapid blinking’ compared to spontaneous blinking in the identification of Parkinson’s disease (PD). Second, to identify whether a reduction in rapid blinking might be an early motor marker of PD in people with subthreshold parkinsonism (SP) recruited from the PREDICT-PD study.
Background: Hypomimia is an indirect marker of bradykinesia, which in turn is a critical diagnostic feature for PD. Most of the studies have focused on spontaneous blinking as a quantifiable aspect of hypomimia. However, impaired rapid blinking has also been reported as an early feature of PD (1).
Method: Spontaneous blinking was recorded during conversation with study participants (cases with PD, SP and healthy controls) for one minute. Rapid blinking was assessed and recorded by instructing participants to blink as fast as they could for 10 seconds. The task was repeated over three trials and blinking was captured on video for analysis. SP in PREDICT-PD participants was defined according to the MDS Task Force criteria for prodromal PD (2).
Results: Thirty-seven participants (PD=17, controls=12, SP= 8) took part in the study. Compared with controls, slower blink rates were recorded in patients with PD during rapid blinking (mean ± SD, PD: 3.3 ± 1.4 blinks/s vs controls: 4.5 ± 0.9 blinks/s, p=0.01), but not with spontaneous blinking (mean ± SD, PD: 0.43 ± 0.28 blinks/s vs controls: 0.65 ± 0.32 blinks/s p=0.09). Rapid blinking had acceptable discriminatory ability to differentiate PD patients from controls (AUC=0.77). The sensitivity for PD using a cut off of <4.2 blinks/s was 77% for a 75% specificity. Individuals with SP also exhibited slower rapid blinking rates compared to controls (mean ± SD, SP: 3.4 ± 0.9 blinks/s vs controls 4.5 ± 0.9 blinks/s, p=0.02).
Conclusion: Conclusion: Rapid blinking is a simple tool for distinguishing PD patients from controls and might act as an objective marker of hypomimia. Further research is needed on a larger scale to study the role of rapid blinking as an early motor marker of PD.
References: 1. Alarcón F, Maldonado JC, Cañizares M, Molina J, Noyce AJ, Lees AJ. Motor Dysfunction as a Prodrome of Parkinson’s Disease. J Parkinsons Dis. 2020;10(3):1067-73. 2. Berg D, Postuma RB, Adler CH, Bloem BR, Chan P, Dubois B, et al. MDS research criteria for prodromal Parkinson’s disease. Mov Disord. 2015;30(12):1600-11.
To cite this abstract in AMA style:
M. Francis, T. Haque, D. Gallagher, C. Budu, A. Lee, A. Schrag, A. Noyce, C. Simonet. Rapid blinking as an early clinical marker of Parkinson’s disease [abstract]. Mov Disord. 2021; 36 (suppl 1). https://www.mdsabstracts.org/abstract/rapid-blinking-as-an-early-clinical-marker-of-parkinsons-disease/. Accessed June 15, 2025.« Back to MDS Virtual Congress 2021
MDS Abstracts - https://www.mdsabstracts.org/abstract/rapid-blinking-as-an-early-clinical-marker-of-parkinsons-disease/