Comment on “The Relationship Between Voluntary Rapid Blinking Rate and Future Development of Neurodegenerative Disease”

Dear Editors,

We congratulate Bahsi and colleagues [1] on their innovative longitudinal investigation of voluntary rapid blinking rate as a potential prodromal marker of neurodegenerative disease. By following older adults for 7 years, the authors move beyond previous cross‐sectional work and introduce a brief, non‐invasive, and clinically accessible assessment that could complement conventional neurological screening. From a sports rehabilitation and geriatric exercise perspective, we would like to suggest four refinements that may strengthen the physiological interpretation and future clinical application of this promising measure.

First, voluntary rapid blinking should be interpreted within the broader framework of neuromuscular function and physical reserve. The authors previously demonstrated an association between rapid blinking and dynapenia [2], while the present study found lower blinking rates among participants who subsequently developed dementia or Parkinson's disease. However, reduced blinking performance may reflect not only early neurodegeneration but also generalized motor slowing, impaired neuromuscular coordination, fatigue, frailty, or reduced executive control. Although grip strength, gait speed, and SARC‐F were included, a more comprehensive physical performance battery incorporating repeated chair stands, balance, lower‐limb power, and dual‐task gait could clarify whether blinking rate contributes information independently of global motor impairment [3]. Such analyses would help distinguish a disease‐specific neurological signal from a broader reduction in physiological reserve.

Second, the temporal pattern of blinking during the 60‐s task may be more informative than the total number of blinks alone. The authors recorded blinking rates at 15, 30, and 60 s, but the strongest predictive association was observed for the initial 15‐s interval. This finding may indicate that rapid motor initiation, rather than sustained blinking capacity, is particularly sensitive to early neurological dysfunction. Alternatively, the later intervals may be increasingly affected by ocular discomfort, attentional decline, or task‐related fatigue. Future studies could calculate a blinking fatigue index, such as the proportional decline from the first 15 s to the final 15 s, and quantify inter‐blink variability, movement amplitude, incomplete closure, and rhythm consistency using high‐frame‐rate video analysis. These digital features may reveal subtle bradykinesia, apraxia, or impaired motor sequencing that cannot be captured by blink counts alone.

Third, habitual physical activity and exercise exposure should be considered as potential modifiers of the relationship between blinking rate and neurodegenerative risk. Regular aerobic, resistance, balance, and coordinative exercise may preserve dopaminergic function, motor timing, executive control, and neuromuscular efficiency. Conversely, low physical activity may contribute simultaneously to reduced motor performance and increased neurodegenerative vulnerability [4, 5]. Without accelerometer‐derived activity, sedentary time, exercise history, or cardiorespiratory fitness data, it remains unclear whether low blinking rate represents an independent prodromal sign or partly reflects physical deconditioning [6, 7]. Stratifying participants according to physical activity level, frailty status, and exercise participation could determine whether the predictive value of rapid blinking differs between physically active and inactive older adults.

Finally, the clinical utility of the test would be enhanced by evaluating its responsiveness to standardized motor and cognitive challenges. A single resting assessment cannot determine whether voluntary blinking is a stable neurological trait or a modifiable performance state. Repeating the task after a brief walking test, resistance exercise bout, or motor‐cognitive dual task could identify individuals with limited neurological reserve who exhibit disproportionate performance deterioration under stress. Similarly, longitudinal exercise interventions could examine whether improvements in physical function, executive control, or motor coordination are accompanied by changes in rapid blinking performance [8, 9]. If blinking rate improves following rehabilitation, it may serve as a responsive marker of functional reserve; if it remains consistently reduced despite physical improvement, it may have greater value as a disease‐specific screening indicator.

In summary, Bahsi et al. [1] provide important preliminary evidence that voluntary rapid blinking may precede the clinical diagnosis of dementia or Parkinson's disease. Integrating multidimensional physical function assessment, time‐resolved blinking characteristics, objective physical activity monitoring, and exercise‐challenge protocols could help determine whether this simple test reflects early neurodegeneration, reduced motor reserve, or an interaction between the two. These refinements may support the development of voluntary rapid blinking from an intriguing observational marker into a practical component of multidomain geriatric and neurorehabilitation screening.

Funding

The authors have nothing to report.

Disclosure

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Ethics Statement

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Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.