Young athletes recovered more quickly from sport-related concussion with an early, progressive, aerobic exercise regimen in a 103-patient randomized trial.
Adolescents who performed individualized, sub-symptom threshold aerobic exercise soon after concussion recovered in a median of 13 days, compared with 17 days for adolescents in a stretching program (P=0.009), reported John Leddy, MD, of the University of Buffalo, and co-authors in JAMA Pediatrics.
“This research provides the strongest evidence yet that a prescribed, individualized aerobic exercise program that keeps the heart rate below the point where symptoms worsen is the best way to treat concussion in adolescents,” Leddy said in a statement.
Because exercise can exacerbate concussion symptoms, the standard of care for sport-related concussion has been prescribed rest until symptoms resolve. This protocol emerged from 2001 guidelines which recommend rest until athletes were “completely asymptomatic,” noted Sara Chrisman, MD, MPH, of the Seattle Children’s Research Institute, in an accompanying editorial.
“However, no definition was provided for the term asymptomatic, and no time limits were placed on rest, and as a result, rest often continued for weeks or months,” Chrisman wrote. With new iterations of guidelines, “clinicians began to use extreme physical and cognitive rest as a treatment for concussion, dubbing this approach ‘cocoon therapy’ — no sports, no physical activity, no screens, and no social interaction.”
In 2009 to 2010, studies showed benefits of rehabilitative exercise in individuals with refractory concussion symptoms, and in 2016, recommendations changed to limit rest to no more than 24 to 48 hours. “These new guidelines opened up the possibility of intervening with exercise at an earlier post-concussion point, with a goal of preventing persistent concussive symptoms,” Chrisman noted.
This led to the current study of exercise to treat acute concussion, the first randomized clinical trial of its kind, according to Leddy and colleagues. In it, they studied 103 teenage athletes (mean age of about 15) who presented within 10 days of sport-related concussion at four concussion clinics in North America. They excluded individuals with depression, anxiety, attention-deficit/hyperactivity disorder (ADHD), and other factors that could delay concussion recovery.
The researchers assessed exercise tolerance with the Buffalo Concussion Treadmill Test, then randomly assigned participants to a progressive sub-symptom threshold aerobic exercise regimen (n=52) or a progressive placebo-like stretching program that would not elevate heart rate substantially (n=51). No interventions started before 48 hours from injury.
Participants were seen an average of 4.9 days post-concussion in the aerobic exercise group and 4.8 days in the stretching group. There were no differences in age, sex, previous concussions, initial symptom severity score, or initial exercise treadmill test and physical examination results between the groups.
In the aerobic exercise intervention, participants exercised at home with a heart rate monitor, 5 days a week for 20 minutes per session, at 80% of the HR achieved at symptom exacerbation on the treadmill test. They were told to rest apart from the prescribed exercise and were seen in person weekly to retake the treadmill test and set a new HR threshold.
Participants rated symptoms daily with the post-concussion symptom scale. The trial stopped when participants reached symptomatic recovery, defined as a score of 7 or fewer points on the symptom scale for 3 days and confirmed by a normal physical exam and the ability to exercise to exhaustion on the treadmill test without exacerbating symptoms.
Delayed recovery — recovery lasting ≥30 days — had a numerically higher but statistically nonsignificant incidence in the stretching (n=7) than the aerobic group (n=2). Total symptom scores decreased more rapidly in the exercise group, but this did not reach significance either.
“The results of this study should give clinicians confidence that moderate levels of physical activity, including prescribed sub-symptom threshold aerobic exercise, after the first 48 hours following sport-related concussion can safely and significantly speed recovery,” Leddy and co-authors concluded.
Research about exercise and concussion has been in transition, and “this is a landmark study that may shift the standard of care toward the use of rehabilitative exercise to decrease the duration of concussion symptoms,” Chrisman observed.
But it has important limitations, she pointed out. The study did not include athletes with depression, anxiety, or ADHD, even though these diagnoses are prevalent in youth seen for concussion. “In addition, the authors did not measure physical activity objectively, and thus it is impossible to estimate the dose of exercise required to elicit a treatment outcome,” she continued.
The study also did not observe participants during exercise, noted Leddy and his group. It did not address mechanisms responsible for the effect of exercise after concussion. Results may not apply to groups like younger children or people with concussions from car crashes, they added, and larger samples from multiple centers using an intent-to-treat design are needed.
This study was supported by the NIH. The researchers reported no conflicts of interest.
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Source: MedicalNewsToday.com
