Systematic evaluation of exercise tolerance using the BCTT within 1 week after SRC did not affect recovery. The degree of early exercise intolerance after SRC was important for prognosis. This has implications for school academic and team preparation.

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.

Objective: To study the effect of early prescribed aerobic exercise versus relative rest on rate of recovery in male adolescents acutely after sport-related concussion (SRC). Design: Quasi-experimental design. Setting: University sports medicine centers. Participants: Exercise group (EG, n = 24, 15.13 ± 1.4 years, 4.75 ± 2.5 days from injury) and rest group (RG, n = 30, 15.33 ± 1.4 years, 4.50 ± 2.1 days from injury). Interventions: Exercise group performed a progressive program of at least 20 minutes of daily subthreshold aerobic exercise. Rest group was prescribed relative rest (no structured exercise). Both groups completed daily online symptom reports (Postconcussion Symptom Scale) for 14 days. Main Outcome Measures: Days to recovery after treatment prescription. Recovery was defined as return to baseline symptoms, exercise tolerant, and judged recovered by physician examination. Results: Recovery time from initial visit was significantly shorter in EG (8.29 ± 3.9 days vs 23.93 ± 41.7 days, P = 0.048). Mixed-effects linear models showed that all symptom clusters decreased with time and that there was no significant interaction between treatment group and time. No EG participants experienced delayed recovery (>30 days), whereas 13% (4/30) of RG participants experienced delayed recovery. Conclusions: These preliminary data suggest that early subthreshold aerobic exercise prescribed to symptomatic adolescent males within 1 week of SRC hastens recovery and has the potential to prevent delayed recovery.

Management of the athlete with postconcussion syndrome (PCS) is challenging because of the nonspecificity of PCS symptoms. Ongoing symptoms reflect prolonged concussion pathophysiology or conditions such as migraine headaches, depression or anxiety, chronic pain, cervical injury, visual dysfunction, vestibular dysfunction, or some combination of these. In this paper, we focus on the physiological signs of concussion to help narrow the differential diagnosis of PCS in athletes. The physiological effects of exercise on concussion are especially important for athletes. Some athletes with PCS have exercise intolerance that may result from altered control of cerebral blood flow. Systematic evaluation of exercise tolerance combined with a physical examination of the neurologic, visual, cervical, and vestibular systems can in many cases identify one or more treatable postconcussion disorders.

BackgroundIn obsessive-compulsive disorder (OCD), individuals feel compelled to repeatedly perform security-related behaviors, even though these behaviours seem excessive and unwarranted to them. The present research investigated two alternative ways of explaining such behavior: (1) a dysfunction of activation—a starting problem—in which the level of excitation in response to stimuli suggesting potential danger is abnormally strong; versus (2) a dysfunction of termination—a stopping problem—in which the satiety-like process for shutting down security-related thoughts and actions is abnormally weak.MethodIn two experiments, 70 patients with OCD (57 with washing compulsions, 13 with checking compulsions) and 72 controls were exposed to contamination cues—immersing a hand in wet diapers —and later allowed to wash their hands, first limited to 30 s and then for as long as desired. The intensity of activation of security motivation was measured objectively by change in respiratory sinus arrythmia. Subjective ratings (e.g., contamination) and behavioral measures (e.g., duration of hand washing) were also collected.ResultsCompared to controls, OCD patients with washing compulsions did not differ significantly in their levels of initial activation to the threat of contamination; however, they were significantly less able to reduce this activation by engaging in the corrective behavior of hand-washing. Further, the deactivating effect of hand-washing in OCD patients with checking compulsions was similar to that for controls, indicating that the dysfunction of termination in OCD is specific to the patient's symptom profile.ConclusionsThese results are the first to show that OCD is characterized by a reduced ability of security-related behavior to terminate motivation evoked by potential danger, rather than a heightened initial sensitivity to potential threat. They lend support to the security-motivation theory of OCD (Szechtman & Woody, 2004) and have important implications both for research into the biological mechanisms underlying OCD and for the development of new treatment approaches.