COGNITION part 2: cognitive rehabilitation

Cognitive rehabilitation can be very broadly defined as any therapy directed at restoring cognitive functioning back to an individual’s previous level or ability.

Now the definitions split further into compensation and remediation.

Compensation is the addition of strategies to bypass the cognitive impairment. The key here is that we are not changing the individual’s ability, instead we achieve improved function through use of an additional tool.

Remediation is focused on restoring impaired skills through training specific domains of functioning. Function is improved through targeting the person’s ability.

Time for the obligatory sports analogy. Dr. Chugh challenges Dr. Boulanger to a race, a 100 m swim. Dr. Boulanger is not as good a swimmer as Dr. Chugh, she used to be, but now she has better things to do. Now Dr. Boulanger can a) use compensation and wear a pair of flippers and swim faster than Dr. Chugh (it’s not cheating, she’s being smart here), or b) she can use remediation and train hard every day to develop the skill required to beat Dr. Chugh.

Assuming that you made the great decision to read part one of this wonderfully written article, you remember that after a concussion, cognition typically does return to baseline functioning, even without any intervention. This means that best practice, as laid out in several guidelines, is, for all intents and purposes, just to wait it out, although, remediation may aid in a faster return to baseline cognitive functioning, and may be necessary for the rare few for whom cognition is not returning to baseline functioning without help. Let us explore the evidence.

Somewhat surprisingly, there really is not a lot of research in regards to cognitive rehabilitation after a concussion. Best practice, according to recent guidelines put out by the Ontario Neurotrauma Foundation (ONF; 2018) and the Centers for Disease Control and Prevention (2018) suggest the use of evidence-based neurorehabilitation strategies, appropriate to the etiology of the impairment, yet neither guideline specifies as to what these might be. Cognitive rest is advised, but no time period is outlined. Thus we know that we should do something to aid in cognitive functioning, but we do not know what, and do not know when. Is it more beneficial to wait for recovery and use compensation in the short-term, or is it best to get started on remediation early on?

Let us begin first with that cognitive rest period. Cognitive rest is a staple recommendation in most guidelines and is essentially the reduction of intellect stimulating activity during the first stage of that concussion recovery. Now it is very easy to say, for example, avoid math problems, Tolstoy, and solving world hunger. Then it gets complicated. Does a board game violate this rule, or cooking, or listening to a podcast? There are no hard and fast rules or definitions of cognitive rest. According to the consensus statement from the concussion in sport conference, cognitive rest is avoidance of all activity requiring increased attention (McCrory et al., 2013), which really could refer to anything that you do actively, or passively, for a prolonged time. A literature review on cognitive rest after concussion came to the conclusion that approximately one or two days of cognitive rest was adequate (Eastman & Chang, 2015). That is the basis of the model that most clinicians recommend, rest for 24 to 48 hours, and then a gradual increase in activity.

Now after that period of rest, we can implement rehabilitation, such as compensation or remediation. Compensation is one of those evidence-based neurorehabilitation strategies suggested by the guidelines (CDC, 2018; ONF, 2018). There was a randomized control trial done on a sample of American veterans that had a history of mild traumatic brain injury, where the experimental group went through 10 weeks of compensatory cognitive training (Caplan et al., 2017). The group with the compensation training scored significantly better than the control group, not just on self reported cognitive impairment, but also on objective measures of attention, memory, verbal fluency, and executive functioning. Another study on a similar sample of American veterans, this time with mild to moderate traumatic brain injury, went through a year of either supported employment, or supported employment in addition to compensatory cognitive training (Twamley et al., 2015). This study did not find too many differences between the groups on cognitive performance, other than prospective memory (memory for things to come e.g., upcoming appointments with the treating team) and affective symptoms (mood related symptoms e.g. lack of motivation to do Moe’s recommended cardiovascular exercises). Essentially compensation is likely beneficial, but we definitely need more research.

There are a couple of literature reviews on cognitive rehabilitation after brain injury, but an important fact to note is that these studies do not differentiate between severity of injury. This becomes a problem as the prognosis in regards to cognition is incredibly different for someone with a severe brain injury (including individuals missing portions of their brain) and a very mild one, such as a concussion. Additionally, many studies group acquired brain injuries together, which include strokes. When looking at mixed brain injury samples, cognitive rehabilitation has shown to result in improvements in cognition (Bogdanova, Yee, Ho, & Cicerone, 2016; Cicerone et al., 2011; Hallock et al., 2016). When we break it down to cognitive domains, there seems to be improvement in executive functioning with a small effect size (Bogdanova et al., 2016; Hallock et al., 2016), verbal memory with a moderate effect size (Hallock et al., 2016), and attention (Bogdanova et al., 2016). We can also look at the effectiveness of computerized cognitive remediation in other populations with less severe cognitive impairment, perhaps more in line with concussion than a broad brain injury population. Studies with major depressive disorder (Motter et al., 2016) and cognitively-healthy older adults (Lampit, Hallock, & Valenzuela, 2014) generally yield small to moderate effect sizes of cognitive remediation, across all cognitive domains. Essentially, it is very likely that computerized cognitive remediation will be beneficial for those with cognitive impairments after concussion, yet research should be conducted before we can draw this conclusion.

There are various different strategies that are employed in the compensation of cognitive deficits after a brain injury, including employing external attention and memory strategies; internal strategies; and task-specific training.

External compensatory strategies

Chances are that you already use some of these strategies throughout your daily life. An external strategy is one where a tool is added, externally to your brain, e.g. using a calendar to remember events.

External memory strategies pretty much include various ways to write things down to make it so that you do not have to remember. For example, having a large ongoing to-do list for work items, which might include, say, writing this article. One could put in the effort and actively work to remember all of the things that need to get done, or just jot them down and not worry about it. External memory strategies are vastly underrated because they enable you to focus all that brain power on the important things that you cannot write down, which you already likely do to an extent, e.g. keeping phone numbers in your contacts rather than remembering them, writing grocery lists, setting a cooking timer. Employing the strategy of “write it down” is tried and true.

You can do the same thing for attention. For example, breaking activities into shorter chunks, to reduce the demand on your attention, and taking breaks. We tell kids to study in 20 minute chunks because efficiency tends to decline after that period, so why not implement the same thing in daily life? Also, do one thing at a time, make sure the environment is not distracting, and maybe set yourself reminders or rewards to keep you on task.

Essentially the beauty of external strategies is that everyone will benefit at any time, but you can also use these more to function at the same level after a concussion.

Internal strategies

Now internal strategies are still compensation, because you are adding something extra to your cognition, but internal strategies are tricks you play inside your brain. For example, we have all used mnemonics. For example, the order of the colours in the rainbow make up the quick statement, “ Richard Of York Gave Battle In Vain,” for red, orange, yellow, green, blue, indigo, and violet; or BEDMAS for the order of operations in math, “Brackets, Exponents, Division, Multiplication, Addition, Subtraction.” This is an internal strategy, as it is a memory trick, but not relying on any external tool.

There are various types of internal strategies for compensation, one fairly useful one is meta-cognitive training. Meta-cognitive training was originally developed for schizophrenia and psychosis, but has been applied successfully across the board. The idea, with metacognition, is that we are thinking, about how we are thinking e.g. the popular strategy is the goal, plan, do, check.

Goal. First stop and take a moment to consider the task at hand and set a goal, e.g. you want to make pulled pork tacos with your boyfriend tonight.

Plan. Then plan this out, set out a strategy, consider all of the variables involved, e.g. you need to start prepping the pulled pork now, so that it can slow cook all day. You will use timers to remind yourself to stir once every hour, you will write a list of the other ingredients to put in the tacos, and figure out when you need to start prepping the rest.

Do it. Follow through with the plan. Make those tacos.

Check. You can check at the end of the task to evaluate your progress, or you can set check points throughout to ask yourself whether you stayed on track and were able to get it done. Were the tacos good? Did you make them efficiently? Could you stay on task better?

One can also develop strategies specific to a task, for example, if you are struggling with coming up with a way to remember to bring everything with you when you leave for work, perhaps you pack the night before and put it all in front of the front door, or perhaps you write a checklist that you put on the back of the door, or perhaps you set an alert on your phone, which activates in a certain place (outside your house).

In summary, compensation is adding something extra to aid in cognition, which everyone can benefit from. The sparse literature evidence for compensation after concussion makes it difficult to recommend compensation as a stand alone method to address persistent cognitive impairment after a concussion, yet it is a very good first step during the initial recovery because it is low effort way to address the gaps in cognition prior to knowledge about the duration of the cognitive impairment.

Coming up with one definition of remediation is difficult, because training cognition can look so incredibly different, yet there are some common features. One definition of cognitive remediation would be the following.

A program that aims to improve cognitive functioning through repeated practice of exercises, at the appropriate level of challenge, that target specific domains of cognition.

That means that there are several important features when it comes to a successful remediation program. Let us explain using physical exercise analogies, which tend to be shockingly applicable to brain injury.

Repeated practice. A good cognitive remediation program is not a one shot ordeal. It takes time and effort to develop skills and restore cognitive functioning. Sports analogy. You can not go from sitting on the couch every night, to waking up one morning and running a marathon. In order to develop that ability you need to start smaller and work hard to get to that goal. You need to commit to running, short runs initially, several times each week. Your brain works the same way, in that you need consistent practice.

Now here is where it gets a little bit more complex, because a good question to ask is whether there is a specific amount or frequency that one should be practicing at. Hallock et al., (2016) looked into factors moderating the success of the remediation and interestingly found that less training, 20 hours or less of training may be more beneficial in the mixed brain injury population. In a healthy older adult population, training for longer sessions (longer than 30 mins), but less frequently (fewer than three times per week) showed the best results (Lampit et al., 2014). Essentially we are not given strong evidence for any useful dose of computerized cognitive remediation, but we do know that frequent practice and use of the program is essential. Thus the recommendation in practice is typically at least three times each week, for periods of at least 20 minutes, with the assumption that more (within reason) may be better.

Appropriate level of challenge. In a cognitive remediation program, you cannot just pick and choose exercises, you need to start with one that provides some challenge, but is not impossible, and continually increase the complexity. Sports analogy. You recently learned to snowboard. You did not start out with the terrain park, or the steep hills, which would have either resulted in comedy or tragedy, instead you learned on the bunny hill, then the slightly steeper hills, and so forth. Your brain functions the same way. You need to begin with the simpler tasks and gradually increase the complexity and level of challenge. There is no benefit to doing an exercise that is much too difficult, nor is there one to doing an exercise that is much too simple. Most remediation programs will then change the level of the exercise based on the user’s speed and accuracy, so that there is a progression from the simple, to the more difficult.

Targeting specific domains of cognition. In a remediation program the exercises target specific cognitive domains, such as sustained attention. For example, at the gym, you might target specific muscle groups, maybe bicep curls, maybe deltoid flies, maybe tricep extensions. A cognitive remediation program may also target more complex systems, such as the combination of visual and verbal memory. Using the exercise analogy, maybe squats, as these target large groups across the lower body. A cognitive remediation program may also target something more complex, such as executive functioning, which relies on the sub skills of attention and memory. Using exercise, perhaps this is more akin to dance, where you are using those smaller muscle groups, but doing something more complex and coordinated with them. The idea with cognitive remediation is that we need to target the specific domains that are impacted, in order to enhance cognitive functioning. In practice this looks like doing exercises that target these specific domains.

A goal oriented or problem focused approach. Really a key component of any rehabilitation, we need to work towards a goal in remediation. There are several tiers to this. First we need to ensure that when we are doing a remediation exercise, we work to achieve the parameters for accuracy and speed that have been outlined, to progress to the next level. A sports analogy will be martial arts. You need to first work towards the requirements of the yellow belt prior to progressing further through the ranks. Second, there is an overall goal for function, which may be real-world, day to day, cognitive functioning, e.g. being able to defend yourself if you need to, or perhaps more specific and measurable, e.g. attaining a black belt.

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Caplan, B., Bogner, J., Brenner, L., Storzbach, D., Twamley, E. W., Roost, M. S., … & Turner, A. P. (2017). Compensatory cognitive training for operation enduring freedom/operation Iraqi freedom/operation new dawn veterans with mild traumatic brain injury. Journal of Head Trauma Rehabilitation, 32, 16-24. doi:10.1097/HTR.0000000000000228

Cicerone, K. D., Langenbahn, D. M., Braden, C., Malec, J. F., Kalmar, K., Fraas, M., … & Azulay, J. (2011). Evidence-based cognitive rehabilitation: updated review of the literature from 2003 through 2008. Archives of Physical Medicine and Rehabilitation, 92(4), 519-530. doi10.1016/j.apmr.2010.11.015

Eastman, A., & Chang, D. G. (2015). Return to learn: A review of cognitive rest versus rehabilitation after sports concussion. Neurorehabilitation, 37(2), 235–244. https://doi.org/10.3233/NRE-151256

Hallock, H., Collins, D., Lampit, A., Deol, K., Fleming, J., & Valenzuela, M. (2016). Cognitive training for post-acute traumatic brain injury: A systematic review and meta-analysis. Frontiers in Human Neuroscience, 10, 537. doi:10.3389/fnhum.2016.00537

Lampit, A., Hallock, H., & Valenzuela, M. (2014). Computerized cognitive training in cognitively healthy older adults: A systematic review and meta-analysis of effect modifiers. PLoS Medicine, 11(11), e1001756. https://doi.org/10.1371/journal.pmed.1001756

Lumba-Brown, A., Yeates, K. O., Sarmiento, K., Breiding, M. J., Haegerich, T. M., Gioia, G. A., … & Joseph, M. (2018). Centers for Disease Control and Prevention guideline on the diagnosis and management of mild traumatic brain injury among children. JAMA Pediatrics, 172(11), e182853-e182853.

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Motter, J. N., Pimontel, M. A., Rindskopf, D., Devanand, D. P., Doraiswamy, P. M., & Sneed, J. R. (2016). Computerized cognitive training and functional recovery in major depressive disorder: A meta-analysis. Journal of Affective Disorders, 189, 184-191. https://doi.org/10.1016/j.jad.2015.09.022

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Twamley, E. W., Thomas, K. R., Gregory, A. M., Jak, A. J., Bondi, M. W., Delis, D. C., & Lohr, J. B. (2015). CogSMART compensatory cognitive training for traumatic brain injury: Effects over 1 year. The Journal of Head Trauma Rehabilitation, 30(6), 391–401. https://doi.org/10.1097/HTR.0000000000000076