Simple Eye Test Identifies Patients Prone to Postoperative Cognitive Dysfunction

Identifying older patients at risk for post-operative cognitive dysfunction may now be as simple as observing them blink. Researchers at Duke Health have discovered that a basic EEG measurement can signal cognitive vulnerability when patients close and open their eyes. Conducted prior to surgery, this non-invasive brain wave assessment helps predict the likelihood of post-operative confusion and attention problems.

"Roughly half of seemingly normal older adults experience problems with thinking, memory, or attention after surgery," said Dr. Leah Acker, lead author of the study appearing in the British Journal of Anaesthesia.

The Duke team used an EEG test to measure a change in brain electrical patterns that cannot be concealed. "Our test measures brain reactivity, which is a kind of automatic response. With something that is automatic, there is really no way to compensate," Acker explained.

The researchers assessed 71 patients over the age of 60 with a simple eyes-closed, eyes-open task to identify disordered arousal or attention. The test not only successfully detected patients with postoperative inattention but also helped gauge the severity of the problems they might experience.

While the cause of cognitive impairments after surgery remains unclear, identifying at-risk patients could assist in preparing them for potential complications. Dr. Acker noted, "This test is quite simple to perform and could prepare clinicians to take precautionary measures to reduce the risk for postoperative inattention, and possibly delirium. More generally, because the brain's reaction to something as simple as opening one's eyes is closely associated with specific attention functions, we expect that this may yield insights into the neural mechanisms underlying neurocognitive vulnerability and resilience."

The study, supported by the National Institutes of Health and the Alzheimer's Drug Discovery Foundation, involved collaboration with various experts, including Megan K. Wong, Mary Cooter Wright, and Marty G. Woldorff.

Reference

Acker, L., et al. (2023). Preoperative electroencephalographic alpha-power changes with eyes opening are associated with postoperative attention impairment and inattention-related delirium severity. British Journal of Anaesthesia. doi.org/10.1016/j.bja.2023.10.037.