Environmental Enrichment to Promote Neuroplasticity and Prevent Cognitive Decline After Acquired Brain Injury

*Disclaimer: the information on this site is intended as general information only and does not serve as personal medical or therapeutic advice. Use with caution and consult a medical professional familiar with your case beforehand.

**Please note that this blog post is an adaptation of a presentation I created for NeuroRestorative.

The treatment of brain injuries has come a long way in the past 20-30 years and yet even today’s science remains limited when it comes to reversing and preventing the signs and symptoms we see post- moderate to severe brain injury. As a rehabilitation professional I often face questions from the care partners, family members and friends of persons living with brain injuries regarding ways they can help support the health and recovery of that person. Often I am hearing these questions in the first days, weeks, and months post-injury, but this concept is just as important in the years following a brain-injury because while we traditionally think of brain injuries as a one-time injury that either stays the same or gets better over time, more recent research suggests that chronic brain injury is actually a progressive condition. 

As rehab professionals working with neurologic conditions we spend a great deal of time learning about evidence-based treatment techniques for minimizing spasticity, improving gait, maximizing outcomes and so forth. We do our best to engage the patient’s support system in helping them perform a home exercise program and making sure they get to their appointments consistently but what if there was more we could recommend? What if there were changes and modifications that could be made in the living environment, whether that be a house, inpatient rehabilitation facility or long-term care facility, that could support their recovery and prevent later cognitive and functional decline for persons with brain injuries? Turns out…there is!

WAIT, BRAIN INJURIES ARE PROGRESSIVE?

Like most of the conditions we treat, no two brain injuries are alike. Brain injuries can be traumatic or nontraumatic in origin. They can be focal (localized) or diffuse (spread out). They can be caused by bleeding in the brain, loss of oxygen to brain tissue, a tumor compressing brain tissue, infection and more. Their effects are dependent on the location of the injury and available medical treatments to ameliorate the damage to the nerves in the brain. While we would expect that the impairments associated with a brain injury would be progressive in the case of a growing tumor or a spreading infection, we may not think about the progression of symptoms following a stroke or traumatic brain injury where the damage is usually contained to the area of initial injury. 

Within the last ten years, however, scientific research is suggesting that a traumatic brain injury is actually just the starting point of an ongoing physiologic process and is increasingly being understood as a progressive disorder. Imaging studies over time reveal reductions in brain volume and white matter integrity beyond what would be expected to occur after scarring and edema reduction are complete. This subacute deterioration may be linked to deterioration in functional and behavioral outcomes in the years after the initial injury. Individuals who have experienced a moderate to severe TBI also have a higher incidence of developing neurodegenerative conditions like Parkinson’s Disease and Alzheimer’s. 

So what we glean from this information is that while our initial efforts may be placed on recovery and rehabilitation, we cannot forget that interventions aimed at slowing or minimizing this subacute deterioration should also be considered. Since there is a good chance an individual will not be undergoing continuous rehabilitation after their injury, it is important that we educate caregivers and care partners on steps they can take to combat this progression. This brings us to one area of their care that can be modified–the environment.

Tomaszczyk et al., 2014 note that: 

Outside of an intensive rehabilitation program, persons with TBI experience  increased idle time, boredom, and little-to-no engagement in meaningful activities. (Turner et al. 2009; Turner et al. 2007; Frasca et al. 2013). They found that persons with TBI are often isolated from former professional and social networks,  often less socially engaged, feel socially isolated and lonely, and may not be able to resume their previously challenging work activities. (Bulinski 2010; Morton and Wehman 1995). Similarly, physical barriers (e.g., accessibility) and poor communication skills serve to compound already reduced community and social integration (Fleming et al. 2013; Struchen et al. 2011). 

With reduction in leisure activities after a TBI, we see an associated increases in television watching

Reduced schedules of activity in moderate to severe TBI patients have been shown to be associated with poorer neural outcomes. 

Since the schedule of activity and surrounding environment is largely under voluntary control of parents, family, care partners, caregivers, rehab staff, etc…this is one thing we can modify, even into the chronic stages of injury, not just immediately after, to help ensure better long term outcomes for these individuals. 

WHAT IS ENVIRONMENTAL ENRICHMENT?

In the research paradigm, environmental enrichment (EE) refers to a multifaceted form of housing that provides enhanced motor, cognitive, sensory and social stimulation. In animal studies this often includes a living environment with a variety of tunnels, toys and nesting materials that are changed regularly to maintain novelty versus a standard environment with just a couple of things that never change. The theory behind EE is that brains in richer, more stimulating environments have higher rates of synaptogenesis. Animal studies like the ones below provide evidence that EE positively effects outcomes after acquired brain injuries in rats:

So, we know that animals are benefiting from an enriched environment, but how does this relate to brain injuries in humans?

While we usually think about neuroplasticity in a positive light–this is how we promote recovery and compensation–it can also be negative. Several researchers have concluded that negative neuroplastic changes secondary to disuse contributes to chronic cognitive and neural decline. Because a person with a brain injury may be unable or not have ample opportunities to participate in activities that are as stimulating as you and I engage in, neuroplasticity begins working against them.

In the brain, the hippocampus is the center for learning and memory and imaging studies are showing atrophy in this area is correlated to the number of hours of EE a person experiences in the first year post-TBI and that engagement in the simple routines that many of these patients may adopt post-injury are not challenging enough to prevent that hippocampal volume loss. 

DOES THIS WORK FOR HUMANS?

While there is pretty robust evidence for EE in animal studies, the human research studies are ongoing and more limited. I will present a few research studies below that outline some different EE paradigms created for human research but I want to start off by acknowledging the limitations of some of these studies. In order to determine that a particular intervention consistently produces a certain outcome, several things need to occur across multiple research studies. In EE studies, we need to see larger but fairly homogenous groups of participants post-TBI receiving similar types and dosing of EE across multiple settings and different time frames. What you will see below and which was highlighted in the Cochrane Review published in 2021 by Qin et al., is that the heterogeneity between studies at this point does not allow for conclusive recommendations for the application of EE in a population of brain-injured clients. Does this mean that EE is not helpful and we should not implement any of these strategies? No, not at this point. To my knowledge there is not evidence that these interventions are harmful or that they do not work, but we have not had enough of the right types of studies to prove with statistics exactly which aspects of EE are critical for enhancing brain plasticity and what dosing is optimal. 

CONSIDERATIONS FOR IMPLEMENTATION OF EE

One of the things I liked the most about the Jantz (2020) and Kumar & Galloway (2021) studies is that they highlight how these interventions can be applied by non-rehab professionals. While installing an overhead track system (Kumar & Galloway, 2021) may not be feasible for all homes, it underscored how creating opportunities for these adults to participate in self-selected standing activities within their home positively impacted several other mobility and social outcomes. 

Jantz (2020) also showed how goals and impairments identified by a rehab professional were used to create enrichment activities that could be implemented by non-rehab staff and family members. In this scenario the school children got to perform novel and salient activities which actually resulted in better long-term outcomes than just performing pencil push-ups, for example, over and over. 

So how can we take the somewhat limited research and apply it with our clientele, residents, patients and family members? Here are some tips:

As you can see, implementing EE strategies will take some time and should be an effort by all those involved in the person’s care, not just rehab professionals. Taking the time to find out what activities are salient to the target clients is essential and being flexible and responsive to how these are working on a daily basis is important. 

DON’T FORGET TO MONITOR RESPONSE TO ENVIRONMENTAL ENRICHMENT ACTIVITIES

If you are excited about implementing some of these strategies at your facility or to begin educating family members and caregivers of those with brain injuries about them, here are some things to take into consideration. As we talked about in the beginning, every brain injury is different and when it comes to moderate to severe brain injuries, tolerance to new, novel and intense activities can vary from person to person and from day to day. These are some things to evaluate when determining which activities to select and when it may be time to take a break:

  • Fatigue
  • Overstimulation
  • Understimulation
  • Behavioral
  • Cognitive and Motor impairments
  • Vision impairments
  • Hearing Impairments 

WHAT ABOUT BARRIERS TO IMPLEMENTATION?

As with all interventions, it is important that we acknowledge the potential barriers to implementation as it will allow us to problem-solve and prepare. Some common barriers to implementing EE are as follows:

  • Staffing or availability of persons to help
  • Budgeting
  • Space limitations
  • Meeting the needs of many individuals
  • Physical and cognitive barriers to participation
  • Lack of awareness or training of staff and family members/care partners
  • Access to transportation and equipment
  • Lack of specifics around dosing and which EE strategies are best
  • Family support 

If you’ve managed to make it this far, I hope this information gets the wheels turning about how we can further our reach and effectiveness as rehab professionals and care partners for persons with brain injuries. I am excited to see how this area of research continues to evolve over time and whether we can narrow down the dosing and interventions that will be most effective for limiting the progression of a chronic acquired brain injury. 

Resources

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Bondi, C. O., Klitsch, K. C., Leary, J. B., & Kline, A. E. (2014). Environmental Enrichment as a Viable Neurorehabilitation Strategy for Experimental Traumatic Brain Injury. Journal of Neurotrauma, 31(10), 873–888. https://doi.org/10.1089/neu.2014.3328

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