The Role of Controlled Exercise in Concussion Management

Abstract

Concussion affects the autonomic nervous system and its control of cerebral blood flow, which may be why uncontrolled activity can exacerbate symptoms after concussion. Traditionally, patients have been advised to restrict physical and cognitive activity until all symptoms resolve. However, recent research suggests that prolonged rest beyond the first couple of days after a concussion might hinder rather than aid recovery. Humans do not respond well to removal from their social and physical environments, and sustained rest adversely affects the physiology of concussion and can lead to physical deconditioning and reactive depression. Some animal data show that early forced exercise is detrimental to recovery after concussion, but other animal data show that voluntary exercise is not detrimental to recovery. We developed the Buffalo Concussion Treadmill Test to systematically evaluate exercise tolerance in persons with prolonged symptoms after concussion (ie, more than 4-6 weeks, which is called postconcussion syndrome [PCS]). Using a predetermined stopping criterion (symptom-exacerbation threshold), akin to voluntary exercise in animals, the Buffalo Concussion Treadmill Test is the only functional test known to safely and reliably reveal exercise intolerance in humans with PCS. The test data are used to develop individualized subthreshold exercise treatment programs to restore the physiology to normal and enhance recovery. Return of normal exercise tolerance can then be used to establish physiological recovery from concussion. New research suggests that absolute rest beyond the first few days after concussion may be detrimental to concussion recovery. However, further research is required to determine the appropriate mode, duration, intensity, and frequency of exercise during the acute recovery phase of a concussion prior to making specific exercise recommendations. For patients with PCS, subsymptom threshold exercise improves activity tolerance and is an appropriate treatment option for this patient population.