At first more theory
The concept of cognitive rest was introduced at the Second International Conference on Concussion in Sport held in Prague in 2004.[14] The Prague statement recognized cognitive rest as a "need to limit exertion with activities of daily living and to limit scholastic activities while symptomatic," and went on to state that, "During this period of recovery in the first few days after an injury, it is important to emphasize to the athlete that physical and cognitive rest is required. Activities that require concentration and attention may exacerbate the symptoms and as a result delay recovery."
At conferences in Zurich in 2008 and 2012, and the respective consensus statements issued shortly thereafter, [1,15] the concept of cognitive rest was reinforced, with physical and cognitive rest being described in both statements as the "cornerstone" of concussion management.
A 2013 systematic review of the literature on the effects of rest and treatment following sport-related concussion [7] noted that, while mental and physical rest in the initial days following a concussion have been strongly encouraged, and resting until symptom-free widely recommended, there had been to that point only three published studies [3,13,16] evaluating the effects of rest in athletes who have suffered a sport-related concussion, and with specific reference to the Moser study [3], stated the absence of a control or comparison group, "so that improvements could have been attributed to a diverse range of factors."
"For these reasons," the study acknowledged that the belief that rest was very likely beneficial following injury was "largely based on animal research, theory and expert consensus:" [4,11]
"First, concussions can have a large adverse effect on physical and cognitive functioning in the first few days post-injury, as the brain is in a state of metabolic crisis, [4] at which time increased energy demand [for a chemical in the brain called adenosine phosphate (ATP)] may hinder the restorative process, and it is believed that rest might facilitate recovery.[8]
Second, in animal injury models, there appears to be a 'temporal window' of vulnerability in which a second overlapping injury results in greater levels of traumatic axonal injury and magnified cognitive and behavioral deficits. Thus, a rest period will reduce the likelihood of the athlete experiencing an overlapping injury.
Finally, it has been demonstrated in rodent models that exercise appears to be good for the injured brain; however, animals that are allowed to exercise too soon after injury do not show the expected exercise-induced increases in molecular markers of neuroplasticity [the ability of the brain to rewire itself after injury]. For these reasons, it is believed that rest is very likely beneficial following injury. However, this is largely based on animal research, theory and expert consensus." [7]
The number of studies supporting the current consensus opinion that limiting extensive cognitive activity reduces the duration of concussion symptoms has, however, been growing.
Cognitive rest helps, no matter when prescribed
In a 2012 study of concussed high school students published in the Journal of Pediatrics, [3] researchers - led by MomsTeam concussion expert neuropsychologist Rosemarie Scolaro Moser, PhD - found that, after one week of strict cognitive and physical rest, concussed athletes scored significantly better on the ImPACT neurocognitive test and reported statistically significant decreases in the number and severity of post-concussion symptoms.
Perhaps surprisingly, the beneficial effects of the week of rest were seen whether the rest came soon after a concussion or weeks to months later. Indeed, more than a quarter of the group which continued to experience concussion symptoms past the 31-day mark (defined by some as the point at which a diagnosis of post-concussion syndrome is appropriate) still demonstrated improvements with prescribed rest comparable to those experienced by concussed athletes in the study who were still in the early stages of concussion recovery.
"Our results represent the first data documenting the efficacy of prescribed rest for the treatment of post-concussion symptoms and cognitive dysfunction, whether the rest is applied in the early or prolonged stages of recovery," Moser observed. The idea that cognitive and physical rest may help improve the condition of patients with post-concussion syndrome is [also] noteworthy," she writes, because "there may be a perception among clinicians that once the 7- to 10-day time period in which the neurometabolic "cascade" [4] has passed, and a patient continues to experience concussive symptoms, cognitive and physical rest is of limited use."
"Without evidence to support the case for rest, especially when weeks or months have passed since the injury, clinicians are met with resistance from athletes, parents, and school and athletic officials who do not see the therapeutic value of missing school or sports when many weeks have already passed," Moser's 2012 study notes. "Athletes, parents, and coaches may balk at the need for, or effectiveness of, rest and inactivity. Without supportive empirical data, patient compliance is threatened and clinician judgments are often challenged and threatened," says Dr. Moser.
Commenting on the finding that even delayed cognitive rest may be beneficial, William P. Meehan, III, MD, former Director of the Sports Concussion Clinic in the Division of Sports Medicine at Boston Children's Hospital and Director of the Micheli Center for Sports Injury Prevention, says that the practice in his clinic has been "always to initiate [cognitive rest], even late in the course [of treatment], if it had not been attempted already." He thus found Dr. Moser's conclusions "reassuring."
"Our research now provides clinicians with solid evidence to show athletes, parents, schools and teams that rest really helps and should not be underestimated, no matter how long the time from injury," says Moser. "I hope it helps us debunk the mistaken philosophy that it is better to push through the pain, than to take the time to heal."
Second study shows benefits of rest
In a second study, published online ahead of print in October 2014 in the journal Brain Injury [17], Dr. Moser sought to replicate and extend her first study, while attempting to control for spontaneous recovery (because there was only a single follow-up period for the athletes in her earlier study, the number who had sustained improvement, recovery and return to their normal lives spontaneously with prescribed rest was unknown).
To do that she studied a small group of thirteen youth athletes who (i) were diagnosed at their school or another facility as having sustained a concussion and had undergone post-concussion testing there, (ii) either were not encouraged to rest following their injury, or did not follow their doctor's orders to rest, and (iii) were later referred for clinical assessment and treatment because they were continuing to experience concussion symptoms.
"Because you can't tell one group of concussed athletes to rest and the other group to not rest but to continue playing in contact sports while they are symptomatic", noted Dr. Moser, the study's design fortuitously allowed the athletes "in a sense [to] serve as their own controls," because they themselves had not rested initially.
Based on the results of her earlier study, Dr. Moser and her colleagues anticipated that the athletes would show significant improvement on neurocognitive testing and self-reporting of concussion-related symptoms after engaging in a week of comprehensive rest (which did not mean bed rest, time spent in a dark room (e.g. so-called "cocoon therapy"), or socially isolation, but did involve staying home from school and avoiding exercise and mentally/physically stimulating activities for 1 week, which represented a major change in their lifestyle).
As in the earlier study, Dr. Moser and her colleagues found that symptoms improved following rest in 54% overall and in 87% of those who had elevated total scores on a post-concussion symptom scale before being prescribed rest. Three-quarters of patients showed statistically reliable improvement in scores on one or more tests of neurocognitive function and four of the thirteen (31%) showed reliable improvements on two or more cognitive domain scores. If reliable improvement on two or more cognitive test scores or improved symptoms scores was used as a measure for improvement, then 61% had evidence of improvement following prescribed rest.
What factors led to the athletes' improvement in cognitive function and symptoms after prescribed rest is still unknown, says Dr. Moser. She noted that the athletes in the study were not typical of the general population, as nearly half had a pre-existing neurodevelopmental problem such as ADHD or learning disability and half reported a history of two prior concussions, both of which previous studies have found to be complicating factors for concussion recovery. Thus she cautioned against generalizing her findings to adolescent athletes without these pre-injury risk factors for longer recovery.
Other factors may also have contributed to the athletes' improvement. Previous studies on mild traumatic brain injury and mental health treatment suggest that some of the improvement may have been the result of (i) education and reassurance provided at the specialty clinic;(ii) non-specific treatment effects (clinician effects, other unmeasured effects); and (iii) placebo effects.
"Given that many adolescents and young adults have stressful and pressured daily lives," Dr. Moser and her colleagues wrote, "it is suspected that being completely ‘unplugged' from all their activities (and much of their stressors) for a few days and getting much more sleep and rest than usual, at least in part, drove the improvements." "In addition, being optimistic that rest would improve their condition may have been another factor in improvement (although it is not uncommon for adolescents to be initially doubtful and resistant to foregoing school and friends for a week)."
"Unfortunately, there is ... much push back to the idea of resting after a concussion because we live such outrageously hurried, busy lives that are technologically and electronically bombarded each day," said Dr. Moser in an email interview. "Years ago, there were no computers, no video games, no cell phones, no texting. TV had a limited number of channels in black and white that were not on 24 hours a day. Moms were not sports taxis and kids stayed home after school and on weekends. Homework was reasonable, and missing school was not perceived as jeopardizing your chances of getting into Harvard. 'Friday Night Tykes' did not exist. We rested on Sundays and lived 'unplugged' lives. Brains had time to rest and recover naturally."
"While the study has limitations, which the authors lay out nicely in the paper, this study does certainly highlight the importance of guided and supervised rest in the recovery process following concussion," said Dr. Johna Register-Mihalik, an assistant professor of Exercise and Sport Science and member of the faculty at the Matthew Gfeller Sport-Related TBI Research Center at the University of North Carolina at Chapel Hill, who was not involved in the study. " Future research should build off of studies such as this to include prospective designs across multiple study sites, adequate control groups and additional, perhaps functional outcome measures."
"There is still so much we don't know about the use of rest for concussion treatment," said Dr. Moser, including how much rest, what kind of rest, who benefits from rest, when should exercise be introduced, and what are the emotional consequences of rest. But, she said, one thing seems to be "a no-brainer: rest is a good thing."
