= Authors =

Aarchie Soni, BHSc Health Sciences Candidate 2024, McMaster University
Jenni Diamond, OT Reg. (Ont.)

 

Recovery after Concussion

A concussion is a type of traumatic brain injury, occurring from an impact to the head or body and resulting in concussion symptoms. Spontaneous recovery from a sports-related concussion typically occurs within 2-3 weeks, however, up to 30% of patients may have longer recovery times.¹ You can read more about concussions in general on our previous blog post here. Guidelines for recovery after concussions and symptom management have changed quite a bit in the past few years, especially when it comes to exercise and concussions.

Previous Guidelines: “Rest is Best”

Previous guidelines for recovery after concussion favoured a “rest is best” approach, partially driven by the finding that excessive activity soon after concussion interfered with and prolonged recovery. As such, past consensus-based recommendations emphasized physical and cognitive rest until complete symptom resolution before training or sport.²

However, it is now understood that prolonged rest is not particularly effective after a concussion. In fact, prolonged rest and social isolation may exacerbate symptoms and delay recovery.² Instead, moderate levels of prescribed physical activity by your healthcare provider may be beneficial in recovery after concussion.¹

The most recent Concussion in Sport Guidelines statement in 2016 also acknowledges that there is insufficient evidence to support the effectiveness of prescribing complete rest. Instead, it is recommended that a brief rest period of 1-2 days after injury be followed by a gradual and progressive sub-threshold (which is at levels below the onset or worsening of concussion symptoms) return to activity, determined in consultation with your physician.³

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…it is recommended that a brief rest period of 1-2 days after injury be followed by a gradual and progressive sub-threshold return to activity…

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Current guidelines: “Exercise is Medicine”

Physical exercise within days of a TBI has been shown to assist in recovery in several ways. A way in which exercise may assist in recovery after concussion includes the induction of factors that promote neuron growth and repair such as brain-derived neurotrophic factor (BDNF).²

Some resulting effects of exercise on recovery may include:

• Promoting neuroplasticity, which is the ability of the brain to reorganize itself, especially after injury, by forming new connections between neurons.²
• Increasing neuronal stem cell proliferation results in the formation of new neurons, which assists in replenishing damaged ones.⁴
• Reducing apoptotic cell death, which decreases neuronal damage surrounding the injury and resulting in a decrease in the area damaged.⁵
• Suppressing formation of reactive astrocytes: After brain injury, astrocytes are immune cells in the brain that are activated in injured areas and result in inflammation and scar formation that can inhibit regeneration of the damaged area. Exercise has been shown to reduce the activation of these reactive astrocytes, assisting in regeneration and recovery.⁶

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…exercise may … [induce] factors that promote neuron growth and repair such as brain-derived neurotrophic factor…

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What type of exercise works best?

Concussion can often cause exercise intolerance, which is the inability to exercise to the level predicted for one’s age and fitness due to an increase in concussion symptoms. The cause of exercise intolerance is unknown, but it is hypothesised that this may occur due to changes in the autonomic nervous system, cardiac stroke volume, and blood flow to the brain.¹ Symptom worsening secondary to exercise may also deter patients from exercise.²

Research has shown individualized subthreshold aerobic exercise to be an effective intervention for recovery. Subthreshold exercise is exercise at an intensity that does not exacerbate symptoms. Walking, running, and stationary cycling are all examples of aerobic exercise that can be done to support recovery.⁷

Research done on this particular intervention has shown that subsymptom aerobic exercise treatments prescribed in the first week after concussion safely speeds recovery.⁷ Aerobic exercise has also shown to increase factors for growth such as BDNF as early as 5 weeks after starting training.²

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…research has shown that exercise can be thought of as an effective medicine to help in recovery after concussion.

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So, research has shown that exercise can be thought of as an effective medicine to help in recovery after concussion. However—as is the case with any other medicine—it is important to consult with your healthcare provider to determine the appropriate dosage for you. Excessive or intense exercise can potentially be harmful, but by working with your healthcare provider to develop a personalized training regimen, you can get on the road-to-recovery faster! For more information on concussions, interventions, and current research, be sure to check our past blog posts.

 

 

References

1. Bezherano I, Haider MN, Willer BS, Leddy JJ. Practical Management: Prescribing Subsymptom Threshold Aerobic Exercise for Sport-Related Concussion in the Outpatient Setting. Clin J Sport Med. 2021 Sep 1;31(5):465–8.
2. Leddy JJ, Haider MN, Ellis M, Willer BS. Exercise is Medicine for Concussion. Curr Sports Med Rep. 2018 Aug;17(8):262–70.
3. McCrory P, Meeuwisse W, Dvorak J, Aubry M, Bailes J, Broglio S, et al. Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016. Br J Sports Med [Internet]. 2017 Jun 1 [cited 2022 Dec 31];51(11):838–47. Available from: https://bjsm.bmj.com/content/51/11/838
4. Itoh T, Imano M, Nishida S, Tsubaki M, Hashimoto S, Ito A, et al. Exercise increases neural stem cell proliferation surrounding the area of damage following rat traumatic brain injury. J Neural Transm [Internet]. 2011 Feb 1 [cited 2022 Dec 31];118(2):193–202. Available from: https://doi.org/10.1007/s00702-010-0495-3
5. Itoh T, Imano M, Nishida S, Tsubaki M, Hashimoto S, Ito A, et al. Exercise inhibits neuronal apoptosis and improves cerebral function following rat traumatic brain injury. J Neural Transm (Vienna). 2011 Sep;118(9):1263–72.
6. Seo TB, Kim BK, Ko IG, Kim DH, Shin MS, Kim CJ, et al. Effect of treadmill exercise on Purkinje cell loss and astrocytic reaction in the cerebellum after traumatic brain injury. Neuroscience Letters [Internet]. 2010 Sep 13 [cited 2022 Dec 31];481(3):178–82. Available from: https://www.sciencedirect.com/science/article/pii/S030439401000861X
7. Leddy JJ, Haider MN, Ellis MJ, Mannix R, Darling SR, Freitas MS, et al. Early Subthreshold Aerobic Exercise for Sport-Related Concussion: A Randomized Clinical Trial. JAMA Pediatrics [Internet]. 2019 Apr 1 [cited 2022 Dec 31];173(4):319–25. Available from: https://doi.org/10.1001/jamapediatrics.2018.4397