Post-concussion syndrome
About 10% of people with PCS develop sensitivity to light or noise, about 5% experience a decreased sense of taste or smell, and about 14% report blurred vision. People may also have double vision or ringing in the ears, also called tinnitus. PCS may cause insomnia, fatigue, or other problems with sleep.
Concussions in American football
There has been promising evidence that blood flow restriction based exercises can be used to improve Post-Concussion Syndrome (PCS). "The leading theory supporting this is that human growth hormone is released in response to increased lactate production from exercise, enhancing the brain function and recovery". This exercise based program could potentially be used in conjunction with aerobic therapy to better improve concussion symptoms during the recovery process. Wu, Yi-Ning, "Stable recovery after aerobic exercise with limb blood flow restriction and cooling in individuals with post-concussion syndrome", Physical medicine and rehabilitation clinics of North America, p. 437-54. 2016.==