Historically, the cornerstone of concussion treatment has been rest. Patients are typically advised to rest until their symptoms go away and when that doesn’t work, they are told to rest some more.
Unfortunately, these recommendations have not been based on scientific study, but rather “expert opinion”. There are very few conditions or injuries in which rest is an effective treatment. Based on the pathophysiology of concussion, an initial period of rest may be beneficial, however we are beginning to understand that prolonging this initial rest period may also be detrimental.
The theory behind rest
Rest fulfils a few important criteria for concussion management:
- Concussion creates an energy deficit within the brain (i.e., the neurometabolic cascade).1 Theoretically, anything that burns energy (cognitive or physical activity) can potentially prolong recovery.
- Early studies examining animals showed that exercise too soon after concussion resulted in a down-regulation of brain-healing modulators (i.e., Brain-Derived Neurotropic Factor (BDNF)2 thereby potentially delaying recovery.
- Activity restriction helps to prevent a secondary concussion injury (Second Impact Syndrome). A second concussion, suffered prior to full recovery of the first, can lead to additive/compounding effects resulting in more severe brain injury and, in rare cases, death.3,4 It is for this reason we believe that restriction of “high-risk” activities should still be included in concussion management practices
The new era
Exercise as treatment
Researchers at the University of Buffalo (UB) began studying exercise as a potential treatment intervention for individuals with persistent symptoms in the early 2000’s. The theory was that ongoing symptoms may be due to autonomic dysregulation, cerebral blood flow abnormalities, and other systemic physiologic dysfunction which may be amenable to aerobic exercise.5
Using a unique protocol in a controlled environment, patients have since demonstrated recovery in numerous trials utilizing sub-symptom threshold exercise.6,7,8
Studies have since also demonstrated sub-symptom threshold aerobic exercise to be a safe and effective treatment strategy for pediatric populations9 and also in more acute stages of recovery;10 something that was once contraindicated. Although the optimal time point to initiate a sub-symptom aerobic exercise rehabilitation program post-concussion has yet to be determined, the trend within the scientific literature is to initiate this earlier rather than later.
Returning to school and work: New evidence for early activation
Similarly, the trend on the educational/vocational front is also beginning to favour early activation vs. the traditional “complete brain rest” approach of the past. Although it is still widely suggested, there is very limited evidence to support complete brain rest in the acute recovery phase of concussion.11 Some evidence is beginning to suggest that too much rest may even be detrimental to recovery.
The potential harmful effects of cognitive rest are (from DiFazio et al., 2015):2
- Anxiety – being told to stay home (often in the dark) and that any activity (cognitive or physical) can damage your brain can be quite alarming to patients. Being told to do nothing can also lead patients to become hyper-focused on their symptoms, thereby delaying recovery.
- The “Nocebo Effect” – we’ve all heard of the “placebo effect” where a treatment with no known therapeutic effect can make someone’s condition improve. The Nocebo Effect is the reverse of this. For example, if a patient expects that a concussion will cause long-term impairment, it is more likely that it will. So telling people to continually rest may be serving to medicalize their condition and perpetuate a prolonged recovery (iatrogenic disability). Click here to listen to a full podcast on concussions and the nocebo effect!
- Depression and other psychological complications – removal from normalcy after any injury can have significant psychological effects. Routine, purpose, and social interaction are important to overall well-being. Studies have found that musculoskeletal injuries that remove someone from normal activities can have the same depressive effect!
A clinical trial by Thomas et al.,12 recently compared a group of patients randomized to 1-2 days of rest, followed by a stepwise return to activity vs. a group of patients randomized to 5 days of strict rest. This study found that the group placed on 5 days of strict rest reported significantly more daily symptoms and had slower resolution of their symptoms over time. In other words, the group pushed back into activity earlier in the recovery, faired better. Although this is the only randomized trial to date, a couple of recent observational studies have uncovered similar results.10,13 Similar to physical activity restriction recommendations, it seems that the trend is beginning to favour shorter cognitive rest durations.
To conclude, cognitive and physical rest may still fill an important role in concussion recovery, however the appropriate recommendation in terms of time spent in a rested state is still yet to be determined.11 We are beginning to discover that prolonged physical and cognitive rest may be detrimental to recovery in concussion patients. We have also discovered the benefits of exercise in reducing symptoms in chronic concussion patients As such, prudent clinicians should suggest a short-term period of physical and cognitive rest as per international guidelines, however they should keep these recommendations short-lived in favour of earlier cognitive and physical activation.
The Complete Concussion Management (CCMI) standard of care is to allow up to 3 to 4 days of cognitive rest before encouraging a graduated return to light cognitive activity. Clinicians should work closely with patients to avoid activities that exacerbate symptoms to a significant degree. The CCMI standard of care on exercise is to initiate a sub-symptom aerobic exercise program with patients that are still experiencing symptoms beyond 14 days post-concussion. The goal being to restore appropriate physiologic and autonomic function as well as place some control in the hands of the patient. Note: Appropriate thresholds must be established by trained therapists prior to initiating an exercise prescription to ensure that patients will achieve maximum benefit and minimize risks.
- Giza CC, Hovda DA. The New Neurometabolic Cascade of Concussion. Neurosurgery. 2014:S24–S33.
- DiFazio M, Silverberg ND, Kirkwood MW, Bernier R, Iverson GL. Prolonged Activity Restriction After Concussion: Are We Worsening Outcomes? Clinical Pediatrics. 2016;55(5):443–51.
- Vagnozzi R, Tavazzi B, Signoretti S, Amorini AM, Belli A, Cimatti M, et al. Temporal Window of Metabolic Brain Vulnerability to Concussions. Neurosurgery. 2007;61(2):379–89.
- Vagnozzi R, Signoretti S, Tavazzi B, Cimatti M, Amorini AM, Donzelli S, et al. Hypothesis of the Postconcussive Vulnerable Brain: Experimental Evidence of Its Metabolic Occurrence. Neurosurgery. 2005;57(1):164–71.
- Leddy JJ, Kozlowski K, Fung M, Pendergast DR, Willer B. Regulatory and autoregulatory physiological dysfunction as a primary characteristic of post concussion syndrome: implications for treatment. NeuroRehabilitation. 2007;22(3):199–205.
- Baker JG, Freitas MS, Leddy JJ, Kozlowski KF, Willer BS. Return to Full Functioning after Graded Exercise Assessment and Progressive Exercise Treatment of Postconcussion Syndrome. Rehabilitation Research and Practice. 2012;2012(2):1–7.
- Leddy JJ, Cox JL, Baker JG, Wack DS, Pendergast DR, Zivadinov R, et al. Exercise Treatment for Postconcussion Syndrome. Journal of Head Trauma Rehabilitation. 2013;28(4):241–9.
- Leddy JJ, Kozlowski K, Donnelly JP, Pendergast DR, Epstein LH, Willer B. A preliminary study of subsymptom threshold exercise training for refractory post-concussion syndrome. Clin J Sport Med. 2010;20(1):21–7.
- Cordingley D, Girardin R, Reimer K, Ritchie L, Leiter J, Russell K, et al. Graded aerobic treadmill testing in pediatric sports-related concussion: safety, clinical use, and patient outcomes. Journal of Neurosurgery: Pediatrics. 2016;18(6):693–702.
- Grool AM, Aglipay M, Momoli F, Meehan WP III, Freedman SB, Yeates KO, et al. Association Between Early Participation in Physical Activity Following Acute Concussion and Persistent Postconcussive Symptoms in Children and Adolescents. JAMA. 2016;316(23):2504.
- Johnson RS, Provenzano MK, Shumaker LM, Valovich McLeod TC, Bacon CEW. The Effect of Cognitive Rest as Part of Post-Concussion Management for Adolescent Athletes: A Critically Appraised Topic. Journal of Sport Rehabilitation. 2016;:1–17.
- Thomas DG, Apps JN, Hoffmann RG, McCrea M, Hammeke T. Benefits of Strict Rest After Acute Concussion: A Randomized Controlled Trial. PEDIATRICS. 2015;135(2):213–23.
- Moor HM, Eisenhauer RC, Killian KD. The relationship between adherence behaviors and recovery time in adolescents after a sports-related concussion: an observational study. Int J Sports Phys Ther. 2015;10(2):225–233.