Jacobs School of Medicine and Biomedical Sciences researchers have published results of the first randomized clinical trial of a treatment in the acute phase after a sport-related concussion.

The study, published February 4 in JAMA Pediatrics, found that adolescent athletes who sustained concussions while playing a sport recovered more quickly when they underwent a supervised, aerobic exercise regimen.

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.

—John J. Leddy, MD

The goal was to evaluate prescribed, progressive sub-symptom threshold exercise as a treatment within the first week of a concussion in adolescents after a few days of rest. Sub-symptom threshold exercise is physical activity that doesn’t exacerbate symptoms. ?

Study involved 103 teenage athletes

The researchers followed 103 participants ages 13 to 18, with nearly the same number of males and females. All were seen at one of the UBMD Orthopaedics & Sports Medicine clinics in Western New York or at the Pan Am Clinic in Winnipeg, Manitoba, Canada, within 10 days after sustaining a sport-related concussion.

Patients who followed the aerobic exercise program took on average 13 days to recover while those in the control group, who performed stretching exercises, took 17 days. In addition, fewer patients in the exercise program took longer than 4 weeks to recover than did patients in the control group.

“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,” says John J. Leddy, MD, clinical professor of orthopaedics and first author on the study. Leddy, who is also director of the University at Buffalo Concussion Management Clinic, says the research team plans to investigate if the treatment is also effective in adults with concussion.

Findings contradict conventional approach

The researchers note that there is no proven treatment for concussion, especially among adolescents, who typically take the longest to recover. “Until now, nothing else has been proven in any way effective for treating concussion,” says Barry S. Willer, PhD, senior author on the study, professor of psychiatry and director of research in the University at Buffalo Concussion Management Clinic. “This is the best evidence so far for a treatment that works.”

The findings directly contradict the conventional approach to concussion, which often consists of nearly total rest and eliminating most physical and mental activities, including schoolwork. “Telling a teenager to go home and basically do nothing is depressing,” Willer says. “It can actually increase their physical and psychological symptoms and we see that particularly among girls. But with our approach, you’re saying, sure, you can return to school and you should start doing these exercises. Their chins are up, Mom and Dad are happy, and so is the student.”

The fact that all states have now passed laws requiring schools to make accommodations for students who have sustained concussions is also helpful, Willer says, so that the student can opt out of some activities during the school day, if necessary.

Treadmill test results key component of study

To determine how much exercise each patient could sustain without exacerbating symptoms, the researchers had each one undergo the Buffalo Concussion Treadmill Test—developed by Leddy and Willer—to determine at what level their symptoms worsen. As the patient walks on a treadmill, the incline is gradually increased and the heart rate is recorded at the point where concussion symptoms intensify. “We prescribed exercise at 80% of that threshold,” Leddy explains, “so each patient’s exercise ‘dose’ was individually tailored.”

Patients were randomly assigned to the aerobic exercise group (52) or to a stretching group (51). Patients in both groups were sent home with a heart rate monitor so they could make sure they stayed below the threshold while exercising.

For patients in the stretching group, the threshold was their resting heart rate. The theory is that aerobic exercise raises the heart rate sufficiently to produce greater control over autonomic nervous system function, a function that is not properly regulated in those with concussion. Both groups performed their assigned exercise for about 20 minutes each day and were required to report compliance and daily symptoms online. Those in the aerobic group either walked on a treadmill, rode a stationary bike, or walked either inside or out.

Recovery defined by independent criteria

Aside from the prescribed exercise, patients were advised to refrain from contact sports, gym class, or team practice. They were given advice about getting schoolwork done and told to avoid excessive use of electronic devices since that can also aggravate symptoms. Each patient’s condition was re-evaluated weekly and as symptoms improved, the “dose” of exercise or stretching was increased, according to the weekly treadmill test results.

Recovery was rigorously defined, requiring agreement among three independent criteria:

• The patient’s reporting a normal (minimal) level of symptoms
• A normal physical examination by a medical doctor
• The return of normal exercise tolerance on the Buffalo Concussion Treadmill Test

The physicians were blinded as to the group assignment of each participant.

Delayed recovery can lead to depression

One surprising finding was that only two participants out of 52 (4%) in the aerobic exercise group took longer than 4 weeks to recover compared to 7 out of 51 (14%) in the stretching group. Four weeks is generally seen as the cut-off for delayed recovery.

This finding did not reach statistical significance, but the scientific literature suggests—by contrast—that between 15% and 25% of adolescents who are told to rest and avoid all exercise will be symptomatic past 4 weeks.

“Reducing the number of concussed adolescents who have delayed recovery has major implications,” Willer says, noting that delayed recovery creates more difficulty with schoolwork, can lead to depression, and puts additional demands on the health care system and its costs.

Calls for health-care system modifications

Michael J. Ellis, MD, study co-author and medical director of the Pan Am Concussion Program in the Department of Surgery and Pediatrics at the University of Manitoba, said that for years his clinic has been successfully using the Buffalo Concussion Treadmill Test and a medically supervised sub-symptom-threshold aerobic exercise program to treat professional, collegiate, and elite adolescent athletes.

“The results of this study suggest that we must build greater capacity within our health-care systems to allow patients access to multidisciplinary concussion programs and clinics that have the medical expertise to carry out early targeted rehabilitation of acute concussion,” he says.

Leddy and Willer are internationally known for their research into the best ways to diagnose and treat concussion—especially the treatment of adolescents—who are the most vulnerable age group for concussions and take the longest time to recover. They have led the emerging body of research findings that show that a patient’s degree of exercise intolerance in the first week after injury—in other words, the lower the threshold of activity at which symptoms increase—is a key clinical indicator of how severe the concussion may be.