Combining breathing exercises with gradual aerobic activity may benefit teens who are recovering slowly from a concussion.
New research found that while the two therapies each offer benefits, together they led to even greater improvement in thinking and memory skills, depression and mood.
The findings are scheduled for presentation in Boston and online at the meeting of the American Academy of Neurology, April 22 to 27.
"When someone has a concussion, it can affect the body's autonomic nervous system, and it is increasingly clear that this underlies the inability to tolerate exercise, problems with thinking skills and mood issues in those with persisting symptoms,"said study author R. Davis Moore, an assistant professor of exercise science at the University of South Carolina.
"Our study used a handheld biofeedback device to help people train their breathing to match their heart rate patterns," Moore said in a meeting news release. "This can help balance the autonomic nervous system and manage symptoms."
Recovery from concussion is considered slow when it takes more than one month for symptoms such as headache, dizziness, depression, mood problems, memory and concentration issues to resolve.
Heart rate variability is the range of time between heartbeats. For example, a person may have a range of 60 to 100 beats per minute.
After a concussion, all patients have changes in this rate, then typically return to normal in a few weeks. For some, these changes continue as if they are stuck in the time period around the injury.
This study included 30 teens who had symptoms for more than a month after being injured during sports or recreation.
Researchers divided them into three groups, matching them by age, gender, physical activity level and body mass index, an estimate of fat based on height and weight.
One group did biofeedback, practicing breathing at a slow rate with a computer program for 20 minutes a night, four nights a week.
Another group did exercise, completing three workouts a week, starting with 20 minutes of low-intensity aerobic activity. This gradually increased in intensity and duration.
The third group did both biofeedback and exercise.
The researchers assessed their concussion symptoms, heart rate variability, sleep, mood and thinking and memory skills at the study's start and again after six weeks.
All groups experienced improved sleep, mood, thinking and autonomic function -- processes such as heartbeat, blood pressure and digestion. Participants who were in the combined biofeedback and exercise group reported greater improvements than those who did exercise or biofeedback alone.
The combined group's reduction in symptom severity was two times greater than those in the exercise group and 1.3 times greater than those in the biofeedback group.
The combined group also had a 1.2 times greater reduction in depression symptoms compared to exercise alone and 1.3 times greater than biofeedback alone.
Those in the combined treatment also had more than 1.4 times the reduction in total mood disturbance than either of the other two groups, as well as significantly greater improvements in attention and working memory. They had greater changes in metrics of heart rate variability than the other two groups, too.
"Managing persistent concussion symptoms is particularly challenging as there are no standard therapies,"Moore said. "These therapies are inexpensive, easy to implement, and can be self-administered, making them feasible and accessible for everyone with persistent symptoms."
One limitation of the study is that it did not include a control group of people who received no intervention for comparison. The results are preliminary and will need to be repeated on larger groups of people, researchers said.
Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.
More information
The U.S. Centers for Disease Control and Prevention has more on concussion.
SOURCE: American Academy of Neurology meeting, news release, Feb. 21, 2023