Protecting your post-op mind: Can cognitive prehab help?

The impact of major surgery extends far beyond the surgical site. It triggers a complex chain of physiological responses that can affect various organs, and the brain is not immune. So brain health after surgery can be a concern for patients and their families.

But while it's possible to experience a decline in brain function after surgery, there are things you can do to help protect the old noggin. Let's delve into what we know about post-operative cognitive impairment and cognitive prehab – that is, preparing your brain before surgery.

What is Postoperative Cognitive Impairment?

Following surgery, some studies have shown that over half of the patients experience noticeable effects on memory and cognitive function. These can emerge as postoperative delirium or postoperative cognitive decline.

Note - these high rates are usually in elderly patients requiring major surgeries.

While both postoperative delirium or postoperative cognitive decline can increase the risk of complications and delay the recovery process, it’s important to understand their differences.

Postoperative Delirium (POD)	A sudden decline in cognitive state that includes confusion and inability to focus lasting 1-3 days after surgery. While you might have difficulty concentrating or feel disoriented, these symptoms are short-lived.
Postoperative Cognitive Decline (POCD)	A long-lasting fog that can settle over your mind in the weeks to months after surgery, making it harder to remember things, stay focused or engage in your regular daily tasks.

Despite delirium being the most common adverse event in older adults following major surgery, post-surgery ‘brain fog’ is not often discussed with healthcare providers. Many patients never ask about it, and many physicians never mention it. However, both POD and POCD can come with significant long-term implications, such as:

• Prolonged hospital length of stay

• Decreased functional independence

• Increased caregiver burden

• Distress to patients and family members

• Increased healthcare costs

• Higher morbidity and mortality

• Greater nursing home care

Understanding your risk

The exact causes of delirium and cognitive decline remain unknown.

At first people thought general anesthesia was a primary cause, but recent studies have debunked this notion, finding no significant difference in postoperative cognitive impairment between patients who had general anesthesia as opposed to other methods, like regional or neuraxial anesthesia.

Instead, advancing age (over the age of 60) and pre-existing cognitive deterioration, spanning from mild cognitive impairment to severe dementia, have emerged as the main preoperative risk factors.

Factors such as inflammation, the nature and duration of the surgical procedure, social support, and functional ability are also potential contributors.

Current guidelines now call for the routine assessment of cognition in older patients before surgery. This evaluation serves two purposes: it (1) establishes a baseline cognitive status and (2) detects any previously undiagnosed impairment.

However, in practice, thorough professional assessment tools (like the Comprehensive Geriatric Assessment, which can offer invaluable insights into cognitive risks before surgery) are often underutilized. These assessments are resource-intensive, requiring the participation of multiple healthcare professionals and need to be done in the limited time period before surgery.

If your healthcare facility does not offer formal cognitive screening, you can still learn more about your risk. At-home evaluations, such as the Self-Administered Gerocognitive Examination (SAGE), provide a convenient means to measure your cognitive function and understand your cognitive risk before surgery. We suggest that you talk with your physician about the possibility of taking such a test. They can provide guidance on administration and interpretation, or suggest alternative assessments that they are familiar with.

What’s in your control? The importance of cognitive reserve

While certain risk factors such as age are beyond our control, there are others we can actively influence. One such factor is our cognitive reserve. Think of cognitive reserve as your brain's ability to withstand the effects of surgery (and other stressors), maintaining normal function thanks to accumulated 'protective' factors like education, mental engagement, and life experiences. The greater your cognitive reserve, the better equipped you are to withstand cognitive stressors.

For instance, research by Tow and colleagues revealed that enhancing cognitive reserve through activities such as brain games (e.g., puzzles, word games) reduced the risk of postoperative delirium. Moreover, building up your cognitive reserve can have broader positive effects, lowering the risk of other post-surgical complications and dementia down the road.

The concept of cognitive reserve is easily visualized.

Is training cognitive reserve beneficial before surgery? 

Can we actually build up our cognitive reserve through brain training? It seems so.

There is plenty of evidence showing that such training can reduce cognitive decline in healthy individuals not requiring surgery. But what about brain training for people about to have surgery?

Some studies suggest that preoperative brain training (referred to as cognitive prehabilitation) may mitigate the risk of postoperative cognitive impairment. However, research in this field is in its initial phases, with only a handful of small-scale investigations conducted so far. For a deeper dive, take a look at some current cognitive prehab studies using the expandable list below:

Saleh (2015)

Subjects: 141 patients aged 60+, scheduled for elective gastrointestinal surgery.

Training: Three, 1-hour training sessions with a researcher in an image visualization and word association task.

Results: Increased cognitive function in certain domains at one week after surgery.

Vlisides (2018)

O'Gara (2020)

Humeidan (2020)

Greaves (2023)

What’s the consensus?

Computerized cognitive training, a method employing computerized exercises aimed at enhancing brain function, has shown promise across various non-surgical populations, including normal cognitive aging, mild cognitive impairment, and traumatic brain injury.

In studies involving surgical populations, challenges related to adherence and compliance during the busy preoperative period have emerged as significant issues. In addition, there is a lack of consistency when it comes to the methods and results of research on cognitive prehab, particularly for computer-based training.

While most of these studies focused on single-mode cognitive training tasks, primarily computer-based, researchers are finding that multi-component approaches, which simultaneously target multiple risk factors, may be more effective. In non-surgical populations, multi-component approaches have shown promise in enhancing or preserving cognition in individuals at risk of dementia and in reducing the incidence of delirium during hospitalization.

The bottom line

While cognitive prehab for surgical preparation requires further investigation to verify its efficacy, it remains an area deserving of continued research efforts.

Excited to explore cognitive prehab but still trying to figure out where to begin?

Stay tuned for our upcoming post, where we will discuss using multiple approaches together to train your brain and give you some practical tips on getting started.