Brimonidine eye drops reveal diminished sympathetic pupillary tone in comatose patients with brain injury.

ABSTRACT:

Background

There is an urgent need for easy-to-perform bedside measures to detect residual consciousness in clinically unresponsive patients with acute brain injury. Interestingly, the sympathetic control of pupil size is thought to be lost in states of unconsciousness. We therefore hypothesized that administration of brimonidine (an alpha-2-adrenergic agonist) eye drops into one eye should produce a pharmacologic Horner's syndrome if the clinically unresponsive patient is conscious, but not if the patient is unconscious. Here, in a first step to explore this hypothesis, we investigated the potential of brimonidine eye drops to distinguish preserved sympathetic pupillary function in awake volunteers from impairment of sympathetic tone in patients in a coma.

Methods

We enroll

SUBMITTER: Jakobsen EW 

PROVIDER: S-EPMC10227128 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature