Pre-op Brain Games Cut Postsurgical
Delirium Risk

Batya Swift Yasgur, MA, LSW

November 16, 2020

Playing cognitive games prior to surgery reduces the risk of postoperative delirium in older adults in a dose-dependent manner, new research suggests.

Results of a randomized controlled trial show surgical patients who engaged in 10 hours of cognitive prehabilitation delivered via an app, also known as "neurobics," were 40% less likely to experience postoperative delirium vs their counterparts who did not engage. Furthermore, the effect appeared to be dose-dependent.

Compared with controls, surgical patients who played between 5 and 10 hours reduced their risk by more than half, and those who played 10 hours or more experienced a 61% reduction in delirium risk.

"Results of this randomized clinical trial show patients who met at least minimum compliance with a preoperative cognitive exercise intervention had a significantly decreased incidence of postoperative delirium," lead author Michelle Humeidan, MD, associate professor of anesthesiology at The Ohio State University Wexner Medical Center in Columbus, told Medscape Medical News.

"Completing as little as roughly 5 hours of brain exercise in the days to weeks leading up to surgery can reduce risk of postoperative delirium in patients 60 years or age and older," she added.

The study was published online November 11 in JAMA Surgery.

Cognitive Reserve

"In perioperative medicine, emphasis is being directed toward improving baseline function in elderly patients to promote successful recovery after surgery," the authors write. These current "prehabilitation" programs include physical exercise, nutrition, behavioral techniques and "optimization of preexisting medical conditions."

The goal is to "augment physiologic and emotional reserve to help patients tolerate the stresses of surgery," the researchers say. However, cognitive activities have not been included in prehabilitation to date.

"As an anesthesiologist, I have always been interested in optimizing the body's organs and systems to tolerate the stress of surgery and promote a successful recovery," said Humeidan.

"Altered attention and thinking (postoperative delirium) is a very common complication after surgery that can have serious consequences, especially in older patients.

"My neuroscience background gave me the idea to pursue increasing 'cognitive reserve' through brain exercise before surgery as a way to optimize brain function and protect against postoperative delirium."

First Large-Scale Application

To investigate, the researchers conducted the Neurobics Trial, which they describe as the "first large-scale application of cognitive prehabilitation in this population."

They recruited patients who were scheduled to undergo major noncardiac, non-neurologic surgery under general anesthesia. Patients included in the study were age 60 years and older and had no cognitive impairment or active depression prior to the study.

Patients who met inclusion criteria (n = 251, median [interquartile range] age 67 years, 64.9% female) were randomly assigned to receive either cognitive prehabilitation (n = 125) or to continue daily activities as usual (n = 126).

The intervention consisted of an app containing a series of brain exercise games focusing on memory, speed attention, flexibility, and problem-solving. Patients were asked to engage in 10 hours of these activities prior to their date of surgery.

The primary outcome was delirium from immediately after surgery to 7 days postsurgical or discharge, and was defined based on a brief Confusion Assessment Method and the Memorial Delirium Assessment Scale, as well as nursing progress notes and a medical record review.

The study groups were well matched in terms of demographics, comorbidity burden, education, baseline cognitive performance, depression indicators, preoperative medications and most frailty indicators.

"Minimum compliance" was defined as participation in at least some of the brain exercises, with 96.8% of participants in the intervention group meeting that criterion.

"Promising" Findings

Of the patients in the intervention group, only 8.8% completed the goal of 10 hours of cognitive exercise; the median preoperative exercise time overall was 4.6 (IQR, 1.3 - 7.4) hours.

The delirium rate for all trial participants was 18.7%. Of the control intervention group, the delirium rate was 23%, whereas the delirium rate in the intervention group (once 4 patients who did not meet compliance standards were removed) yielded a delirium rate of 13.2% (P = .04).

The risk for delirium remained lower in the intervention group, compared with the control group, even when the researchers adjusted for surgical procedures and response to frailty indicators.

No statistical differences were found between the groups in postoperative delirium onset day, duration, or total delirium-positive days.

Participants in the intervention group who spent more time engaging in cognitive exercises had lower rates of delirium compared with those who spent less time (P = .20).

Time spent on cognitive exercises prior to surgery Postoperative delirium rate
<5 hours 18.4%
5-10 hours 10.2%
>10 hours 9%


"The Neurobics Trial results are certainly promising and support that brain exercise before surgery can reduce risk of postoperative delirium, but more work needs to be done to determine the ideal brain exercise activities, timing, and effective dosage," Humeidan said.

She added that having patients consider a low-risk intervention like brain exercise before surgery is "certainly reasonable, but it will take more time and investigation before it will be routine."

Low Cost, Low Risk

Commenting on the study for Medscape Medical News, Katie J. Schenning, MD, MPH, MCR, associate professor of anesthesiology and perioperative medicine and assistant medical director, Preoperative Medicine Clinic, Oregon Health & Science University, Portland, called it "an exciting contribution to the field of postoperative delirium research."

Schenning, who was not involved with the study, said: "The authors present a low-cost, low-risk intervention that patients can perform in the comfort of their homes, which leads to a clinically meaningful reduction in delirium."

She also found it "encouraging" that even minimally compliant patients experienced "meaningful benefit."

"Practically speaking, it might be more feasible for this demographic of patients to engage in brain exercises that are not dependent on technology; however, low-tech strategies would be more difficult to trace from a research perspective," she said.

She suggested that perioperative physicians can "encourage patients to challenge themselves with 'brain games' before surgery in order to potentially reduce the risk of developing postoperative delirium."

Support for this trial was provided by institutional funds from the Ohio State University Department of Anesthesiology and Neuroscience Research Institute.

Humeidan received 2 years of loan repayment support from the National Institutes of Health Loan Repayment Programs and nonfinancial support from Lumos Labs Inc during the conduct of the study, as well as personal fees from Medtronic outside the submitted work. The other authors' disclosures are listed in the original article. Schenning reports receiving research grants from the National Institute on Aging, the Alzheimer's Association, and the Foundation for Anesthesia Education and Research.

JAMA Surg. Published online November 11, 2020. Abstract

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