Letter to the Editor. Pupillometry and neurotrauma: point-of-care technologies versus point-of-care techniques

View More View Less
  • 1 Fulda Clinic, Fulda, Germany;
  • 2 The Ohio State University, Columbus, OH;
  • 3 Narayana Medical College and Hospital, Nellore, Andhra Pradesh, India; and
  • 4 Center for Biomedical Research (CIB), Faculty of Medicine, University of Cartagena, Colombia
Free access

TO THE EDITOR: We read with interest the article by Joseph et al.1 (Joseph JR, Swallow JS, Willsey K, et al. Pupillary changes after clinically asymptomatic high-acceleration head impacts in high school football athletes [published online November 26, 2019]. J Neurosurg. doi:10.3171/2019.7.JNS191272).

The role of point-of-care testing has been increasingly recognized as a way to improve outcomes in healthcare. The available data on point-of-care testing are limited and suggest that point-of-care testing is costlier than traditional laboratory investigations.2 In contrast to laboratory investigations, in the present article the authors explore the role of the clinical parameter “measurable changes in pupil response in clinically asymptomatic high school football athletes following high-acceleration head impacts”1 as an alternative to point-of-care technologies. We congratulate the authors for their excellent work, which expands the concept of clinical examination using clinical markers (in contrast to laboratory biomarkers) as highly cost-effective, noninvasive, and efficient tools to monitor the injured in a real-life scenario.

To further add to the comprehensive discussion presented by Joseph et al., we would like to add that the innervation of the eyes represents a complex balance of sympathetic and parasympathetic functions. This balance could be altered by many mechanisms, including intoxication, trauma to the head, direct trauma to the eyes, etc. For athletes participating in contact sports, it has been reported that up to 90% will experience a head injury, depending on the type of sport, which makes the topic of Joseph et al.’s article crucial for athletes, parents, trainers, lawyers, etc.

The information presented by these authors is important for two reasons. First, regarding the baseline conditions of pupil constriction velocity, latency to constriction, maximum size, and percentage change, in the reported study maximum constriction velocity and dilation velocity were recorded in controls before the events of head trauma and serve as baseline data. In addition, pupil dilation velocity, percentage change in pupil size, and maximum constriction velocity parameters showed statically significant alterations after a mild traumatic brain injury (mTBI), findings that have already been confirmed by Ciuffreda et al.3 However, the changes of these parameters could not be interpreted to be due only to anatomical changes or neuron pathway dysfunction. As already described by Shetty et al.,4 about 27% of the patients after an mTBI develop white matter changes. Of the neuropsychological assessments used, the 5- and 6-Digit Backward Recall, the modified Balance Error Scoring System (BESS), and the Immediate 5-Word Recall significantly improved longitudinally in mTBI subjects and facilitated differentiation between the mTBI subjects and controls. Female subjects tend to score more points on symptom severity scores, as well as older patients (≥ 25 years of age) and patients with a history of psychiatric disorder. The second reason for the importance of this study is that it could serve as a basis for upgrading the graduated return-to-play protocol, which is already in use but should include the application of clinical findings. The quantitative pupillometry method used by Joseph et al. offers a unified, objective method to determine the parameters of the pupil in relation to mTBI.

Combining neuroimaging, biomarkers, neurocognitive evaluation, quantitative pupillometry, and clinical findings is needed to increase our understanding of the neurophysiological correlations between these variables. In addition, anatomical changes are often clinically silent, and uncertainty remains regarding which neuron pathway dysfunctions are without anatomical correlations. We believe that the present study will provide a road map to conduct further research and elucidate how clinical techniques can be used as reliable outcome markers as well as reliable clinical biomarkers that can be incorporated into an alternative point-of-care method to identify and follow up cases of mTBI injuries with neurological sequelae.

Disclosures

The authors report no conflict of interest.

References

  • 1

    Joseph JR, Swallow JS, Willsey K, Pupillary changes after clinically asymptomatic high-acceleration head impacts in high school football athletes [published online November 26, 2019]. J Neurosurg. doi:10.3171/2019.7.JNS191272

    • Search Google Scholar
    • Export Citation
  • 2

    Gutierres SL, Welty TE. Point-of-care testing: an introduction. Ann Pharmacother. 2004;38(1):119125.

  • 3

    Ciuffreda KJ, Joshi NR, Truong JQ. Understanding the effects of mild traumatic brain injury on the pupillary light reflex. Concussion. 2017;2(3):CNC36.

    • Search Google Scholar
    • Export Citation
  • 4

    Shetty T, Nguyen JT, Cogsil T, Clinical findings in a multicenter MRI study of mild TBI. Front Neurol. 2018;9:836.

Author: Jacob R. Joseph
View More View Less
  • University of Michigan, Ann Arbor, MI
Keywords:

Response

We appreciate the interest in our research expressed by Pavlov et al., and their comments are well taken. The physiology of the pupillary light reflex is highly complex, making it difficult to definitely state what the root cause of changes may be. The variable activation of the autonomic nervous system during sporting activity is particularly difficult to control for. However, we do believe that the results presented in our article are promising, and we agree that objective clinical measures such as quantitative pupillometry and eye tracking can potentially enhance return-to-play protocols.

If the inline PDF is not rendering correctly, you can download the PDF file here.

Contributor Notes

Correspondence Luis Rafael Moscote-Salazar: rafaelmoscote21@gmail.com.

INCLUDE WHEN CITING Published online April 24, 2020; DOI: 10.3171/2020.1.JNS193487.

Disclosures The authors report no conflict of interest.

  • 1

    Joseph JR, Swallow JS, Willsey K, Pupillary changes after clinically asymptomatic high-acceleration head impacts in high school football athletes [published online November 26, 2019]. J Neurosurg. doi:10.3171/2019.7.JNS191272

    • Search Google Scholar
    • Export Citation
  • 2

    Gutierres SL, Welty TE. Point-of-care testing: an introduction. Ann Pharmacother. 2004;38(1):119125.

  • 3

    Ciuffreda KJ, Joshi NR, Truong JQ. Understanding the effects of mild traumatic brain injury on the pupillary light reflex. Concussion. 2017;2(3):CNC36.

    • Search Google Scholar
    • Export Citation
  • 4

    Shetty T, Nguyen JT, Cogsil T, Clinical findings in a multicenter MRI study of mild TBI. Front Neurol. 2018;9:836.

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 129 129 42
PDF Downloads 55 55 30
EPUB Downloads 0 0 0