Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Sep 10;11(9):1194.
doi: 10.3390/brainsci11091194.

Atypical Pupil Reactions in Brain Dead Patients

Joanna Sołek-Pastuszka  1 , Małgorzata Zegan-Barańska  2 , Jowita Biernawska  1 , Marcin Sawicki  3 , Waldemar Iwańczuk  4 , Kornel Chełstowski  5 , Romuald Bohatyrewicz  1 , Wojciech Dąbrowski  6 , Klaudyna Kojder  1
Affiliations

Atypical Pupil Reactions in Brain Dead Patients

Joanna Sołek-Pastuszka et al. Brain Sci. .

Abstract

Background: During routine diagnosis of brain death, changes in pupil diameter in response to the stimulation of peripheral nerves are sometimes observed. For example, pupillary dilation after diagnosed brain death is described in the literature as the ciliospinal reflex. However, pupil constriction creates diagnostic doubts.

Objective: The pupillometric analysis of pupil response to stimulation of the cervicothoracic spinal cord in patients with diagnosed brain death.

Methods: Instrumental tests to confirm the arrest of cerebral circulation were performed in 30 adult subjects (mean age 53.5 years, range 26-75 years) with diagnosed brain death. In addition, a pupillometer was used to measure the change in pupil diameter in response to neck flexion.

Intervention: Flexion of the neck and measuring the response in change of the pupil with the use of the pupillometer.

Results: The change in the pupil was observed in the examined group of patients. Difference in pupil size ≥ 0.2 mm was observed in 14 cases (46%). In five cases (17%), pupil constriction was found (from 0.2 to 0.7 mm). Measurement error was +/- 0.1 mm.

Conclusions: Both pupillary constriction and dilatation may occur due to a ciliospinal reflex in patients with brain death. This phenomenon needs further research in order to establish its pathophysiology.

Keywords: brain death; ciliospinal reflex; pupillary reactivity; pupillary size; pupillometer.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Ciliospinal reflex pathway.
See this image and copyright information in PMC

References

    1. Nowak E., Pfitzner R., Przybyłowski P. Polish Guidelines on Diagnosing Brain Death in Adults vs. the International Perspective: Are We in Need of an Update? Transplant. Proc. 2016;48:1394–1398. doi: 10.1016/j.transproceed.2016.01.040. - DOI - PubMed
    1. Tripathy K., Simakurthy S., Jan A. StatPearls. StatPearls Publishing; Treasure Island, FL, USA: 2019. Ciliospinal Reflex. - PubMed
    1. Couret D., Boumaza D., Grisotto C., Triglia T., Pellegrini L., Ocquidant P., Bruder N.J., Velly L.J. Reliability of standard pupillometry practice in neurocritical care: An observational, double-blinded study. Crit. Care. 2016;20:99. doi: 10.1186/s13054-016-1239-z. - DOI - PMC - PubMed
    1. Taylor W.R., Chen J.W., Meltzer H., Gennarelli T.A., Kelbch C., Knowlton S., Richardson J., Lutch M.J., Farin A., Hults K.N., et al. Quantitative pupillometry, a new technology: Normative data and preliminary observations in patients with acute head injury. J. Neurosurg. 2003;98:205–213. doi: 10.3171/jns.2003.98.1.0205. - DOI - PubMed
    1. Lewis A., Greer D. Current controversies in brain death determination. Nat. Rev. Neurol. 2017;13:505–509. doi: 10.1038/nrneurol.2017.72. - DOI - PubMed

LinkOut - more resources