Christopher C. Giza, Meeryo C. Choe, Karen M. Barlow. Determining if Rest Is Best After Concussion. JAMA Neurol. Published online March 5, 2018. doi:10.1001/jamaneurol.2018.0006
The consensus on management of mild TBI (mTBI), driven largely by those caring for patients recovering from sport-related concussions, moved from avoiding early activities with risk of repeat mTBI to restrictions on all physical activities, whether they held significant risk for repeat mTBI or not. However, there remained little evidence to guide the timing and duration of restrictions on physical activity, and many interpreted this lack of evidence as meaning there should be complete physical rest as long as the patient was symptomatic. Symptoms then served as a surrogate clinical measure for physiological dysfunction, with little consideration to the underlying mechanisms that generated the symptoms or their timing and evolution after mTBI.
As concussion awareness increased, small, uncontrolled clinical studies suggested that high levels of activity were associated with more symptoms, and that patients who were prescribed physical and cognitive rest over time seemed to improve. This finding led to subtle changes in management, with more rigid restrictions on activity that now incorporated the ill-defined entity of “cognitive rest.” Cognitive rest was defined as limited mental activity, with avoidance or reduction of “cognitive exertion” such as reading, homework, job activities, studying, and playing video games. Restrictions on physical and mental exertion continued to grow, particularly in subsets of patients with mTBI who had prolonged symptoms. In addition to the “rest” described above, many patients were prescribed restrictions designed to reduce neural stimulation, such as wearing sunglasses, staying in a dark room, avoiding screen time of any kind, and prohibiting the use of electronic devices for activities such as texting, checking email, and accessing social media.
At several points along our evolution of evidence-based management of mTBI, basic science and its translation have illuminated the path to clinical change. In the post-mTBI period, voluntary exercise at the appropriate time window enhanced recovery and cognition in animal models, sometimes even very early after injury. Even as clinical practitioners were using “cocoon therapy,” a form of severe restriction of activity designed to reduce brain activity by reducing sensory, motor, and cognitive stimulation, others were noting that “complete brain rest” could have negative consequences. Prolonged absences from school, anxiety, depression, deconditioning, sleep disturbances, and other problems were increasingly seen as challenges in the recovery from mTBI.
From the seminal work of Bennett et al, basic neuroscience has conclusively demonstrated that neural activity is an essential part of brain development. Enriched environments lead to enhanced neurotransmission, strengthened synapses, increases in neurotrophins, greater cortical thickness, and better cognition. Stimulating environments in young humans were shown to result in structural and functional brain changes, and impoverished environments during childhood could leave long-lasting deficits. More recently, pharmacotherapies that blunt neural activity, such as sedatives and anticonvulsants, were shown to have detrimental effects in both preclinical and clinical investigations.
So why would complete brain rest be good for a developing brain? The reality is that total restriction of brain activity is not ideal, even for an injured brain. Although it makes some sense acutely to diminish stimuli that exacerbate symptoms, this practice has led to a slippery slope of progressively limiting environmental stimuli and physical activity during recovery until the patient with mTBI is “cocooned.” In a retrospective study examining postconcussion activity, the moderate activity group did the best. A subsequent prospective study showed that there was no added recovery benefit in the quartile with the least activity compared with those with moderate activity. More recent prospective studies have suggested there is benefit from timely return to brain activity for recovery from mTBI or concussion. Although consensus still supports no return to activities with a risk of repeat mTBI if acute concussion-related symptoms are ongoing, recent guidelines do encourage earlier introduction of symptom-limited cognitive and noncontact physical activity. Furthermore, submaximal activity has been introduced therapeutically to facilitate recovery in both adults and children with chronic symptoms. Controlled exercise is now newly included as a consideration in consensus recommendations for the management of sport-related concussion.
In the end, evidence-based removal from activities with a risk of repeated mTBI was extrapolated beyond existing data to incorporate a broad range of restrictions on physical and cognitive activity. And, as can so easily occur when practice or policy is altered with good intentions but in the absence of understanding or data, unanticipated consequences arose with cocoon therapy and complete brain rest that may have contributed to prolonged recoveries. Over time, both basic and clinical science caught up with practice, informing a more refined approach of individualized management of activity after mTBI, with initial brief rest followed by controlled reintroduction of cognitive activities, nonrisky physical activities and, eventually, a return to normalcy.
Courtesy of: https://www.medpagetoday.com/neurology/generalneurology/71561