Story Time
When I was 11 my best friend on my ice hockey team got a concussion and couldn’t play for 3 months. In that time I didn’t see her much and imagined my dear friend sitting in a dark room for 3 months not able to watch t.v., listen to the Jonas Brothers, or come to hockey practice. For the longest time this is how I imagined concussion recovery and for the longest time doctors agreed this was the best way to treat concussions. (If you want to learn more about concussions and other mild traumatic brain injuries check out this post by Sam Rizzo)
Concussion Treatment Now
Flash forward almost 12 years and a lot has changed in the world of concussion treatment. Where complete rest and inactivity was previously prescribed, researchers are discovering that small increases in exercise and other treatments are actually more beneficial. “Rest is best” is now no longer the doctors favorite song, instead they’re singing “submaximal aerobic exercise,” “vestibular and visual therapy,” and “cervical spine physiotherapy.”
Dr. John Leddy and colleagues recently published an article explaining the benefits of small doses of exercise following sports related concussions (SRC). They explained how total removal from sport after 2 days leads to declines in mental health and moderate exercise during recovery leads to lower chances of children and adolescents developing persistent postconcussive symptoms (PPCS) which can last for 2 to 4 months after injury. Other research by the Concussion in Sports Group has also found insufficient evidence regarding complete removal from exercise.
Why is exercise tolerance so low after concussions? Leddy and colleagues hypothesis a dysregulation between the body’s response to exercise. In a recent study, they found that female college athletes have an abnormally low sensitivity to arterial CO2 which caused hypoventilation, leading to raised PaCO2 levels. As a result cerebral blood flow increased, which is associated with headache and dizziness, two major symptoms of PPCS. Other studies cite similar information such that there seems to be a miscommunication between the autonomic nervous system and cerebral blood flow causing the overall level of exercise tolerance to be reduced. From here, research points toward subthreshold exercise as a way to promote recovery.
Why exercise?
Research regarding the benefits of exercise on our brains in widely spread, with the overall finding being that aerobic exercise can act as a protective factor in cognitive decline (to learn more about your brain on exercise, check out this post by Grace Egan). Leddy and colleagues list many benefits of motivated, moderate exercise in animals models. Some of the benefits include promotion of neuroplasticity, reduction of neuronal cell death, and improvement of cognitive performance.
What can we learn from this? Leddy and colleagues cite this information as reasoning to actually help improve athletes’ health. They recommend exercising until reaching a sub-threshold heart rate using the Buffalo Concussion Treadmill Test (BCTT) to establish the athlete’s exercise threshold following injury. From there, exercise is scaled down to about 80-90% of their threshold (that is, before symptom onset) and steadily increased over a few weeks. By doing so, athletes are able to still exercise during injury, thus maintaining their mental health as well as inducing optimal brain recovery from physiological symptoms of concussion.
Other Hoaxes
Concussions are more than just headaches and require more than just headache treatment. Many symptoms of concussions include cervical injury and vestibular/ocular dysfunction as well. In addition to gradual increase of exercise, athletes who experience these symptoms have been shown to benefit from vestibular and visual therapy as well. These exercises include eye saccades, smooth pursuit, and balance drills aimed to help with eye fatigue, balance, and dizziness (for a more detailed overview of the benefits of vestibular therapy check out this website). While these treatments don’t have the potential for a fun rhyme, they do have the potential to get athletes back to playing and significantly reduce the time spent injured.
Now when young hockey players think about concussion recovery, hopefully something like this (see below) will come to mind instead.
References
Leddy, J. J., Haider, M. N., Ellis, M., & Willer, B. S. (2018). Exercise is medicine for concussion. Current Sports Medicine Reports, 17(8), 262-270. doi:10.1249/JSR.0000000000000505
https://psych-neuro.com/2019/02/22/how-mild-is-mild-concussions-and-mild-traumatic-brain-injury/
https://psych-neuro.com/2019/03/02/work-out-your-brain/
Images
Leddy, J. J., Haider, M. N., Ellis, M., & Willer, B. S. (2018). Exercise is medicine for concussion. Current Sports Medicine Reports, 17(8), 262-270. doi:10.1249/JSR.0000000000000505
https://www.filmsupply.com/collections/dark-and-eerie/1654
header image: https://www.pinterest.com/pin/27936460168978350/
On Psychology and Neuroscience 