Time to Ditch the Cocoon?
Written by Jane Crosby
Edited by Priya Ram
March 22, 2022
Edited by Priya Ram
March 22, 2022
Lights out, blinds closed, brain switched off. You’ve recently sustained a concussion and the only way to recover is to rest from the activities you love most. Wrong! Gone are the days of waiting around for symptoms to ease while work, school, and life go on without you. The “cocoon” or “rest is best”[1] consensus-based method is going out of style and physicians are shifting to a more active, evidence-based approach to concussion care. Research shows that exercise can help, not hurt, your chances of a quick recovery, getting you back up to speed after injury.
While a short period of rest during the acute stage of injury is still thought to be beneficial, “cocoon”-like rest lasting for more than 48 hours has shown to prolong recovery and develop into chronic post concussive symptoms[2]. In a recent rodent study, early voluntary and therefore self-regulated exercise on running wheels showed improvement in cognition and motor function linked to neuroplasticity whereas “cocooned” rodents did not recover[3]. The self-regulation aspect is important because it accounts for individual symptom thresholds. These demarcate the range of exercise that is beneficial, avoiding an uptick in stress hormones while inducing brain derived neurotrophic factor (BDNF)[3], a protein that promotes the growth and repair of neurons.
These findings in animal models are not alone in encouraging regulated exercise following a concussion. A team of researchers at the University at Buffalo proposes sub-maximal aerobic exercise as a non-pharmacological, or rehabilitative, “medicine” for concussion that targets autonomic nervous system (ANS) dysfunction. Post-injury ANS dysfunction manifests in ventilation that is too shallow or slow, causing a rise in your blood’s CO2 concentration[1]. This increase triggers excessive blood flow within your brain and a type of symptom exacerbation called exercise intolerance.
The University at Buffalo study in question used exercise intolerance as a “physiological biomarker” of concussion and evaluated the “symptom-exacerbation exercise threshold in concussed patients'' using the Buffalo Concussion Treadmill Test and a calibrated stationary bike version[1]. Each patient’s threshold heart rate was identified and they were prescribed an individualized, subthreshold “dosage” of exercise at an increasing target heart rate for just 20 minutes a day or until symptoms were provoked. When patients were able to increase their exercise intensity to 20 minutes at 80% or greater of their age-predicted maximum without provoking symptoms, they were considered recovered from the physiological impacts of concussion and cleared to begin a return-to-play protocol, a gradual return to complete normal activity[1]. When the overall recovery of patients experiencing persistent post concussive symptoms treated with these exercise regimes was reviewed, it was found that 72% had returned to normal daily activity and functioning within one year[4], a remarkable timeline for complete recovery in comparison to the uncertainty the cocoon method brings.
These studies mark the beginning of a new era of brain injury care in which patients are treated with individualized rehabilitation programs rather than blanket physical, social, and cognitive isolation. For physiological aspects of concussion, exercise is medicine and the regulation of the autonomic nervous system can pave the way for complete neurological recovery without bringing your normal life to a screeching stop.
References:
- Leddy JJ, Haider MN, Ellis M, Willer BS. Exercise is Medicine for Concussion. Curr Sports Med Rep. 2018;17(8):262-270. doi:10.1249/JSR.0000000000000505
- 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. doi: 10.1542/peds.2014-0966.
- Mychasiuk R, Hehar H, Ma I, Candy S, Esser MJ. Reducing the time interval between concussion and voluntary exercise restores motor impairment, short-term memory, and alterations to gene expression. Eur J Neurosci. 2016;44(7):2407–17. doi: 10.1111/ejn.13360.
- 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;2012:705309. doi: 10.1155/2012/705309. Epub 2012/02/01.