A preliminary study of subsymptom threshold exercise training for refractory post-concussion syndrome. Clin J Sport Med. 2010 Jan;20(1):21-7. Leddy JJ, Kozlowski K, Donnelly JP, Pendergast DR, Epstein LH, Willer B.
To evaluate the safety and effectiveness of subsymptom threshold exercise training for the treatment of post-concussion syndrome (PCS).
Prospective case series.
University Sports Medicine Concussion Clinic.
Twelve refractory patients with PCS (6 athletes and 6 nonathletes).
Treadmill test to symptom exacerbation threshold (ST) before and after 2 to 3 weeks of baseline. Subjects then exercised 5 to 6 days per week at 80% ST heart rate (HR) until voluntary peak exertion without symptom exacerbation. Treadmill testing was repeated every 3 weeks.
MAIN OUTCOME MEASURES:
Adverse reactions to exercise, PCS symptoms, HR, systolic blood pressure (SBP), achievement of maximal exertion, and return to work/sport.
Pretreatment, ST occurred at low exercise HR (147 + or – 27 bpm) and SBP (142 + or – 6 mm Hg). After treatment, subjects exercised longer (9.75 + or – 6.38 minutes to 18.67 + or – 2.53 minutes, P = .001) and achieved peak HR (179 + or – 17 bpm) and SBP (156 + or – 13 mm Hg), both P < .001 versus pretreatment, without symptom exacerbation. Time series analysis showed significant change in rate of symptom reduction for all subjects and reduced mean symptom number in 8/11. Rate of PCS symptom improvement was related to peak exercise HR (r = -0.55, P = .04). Athletes recovered faster than nonathletes (25 + or – 8.7 vs 74.8 + or – 27.2 days, P = .01). No adverse events were reported. Athletes returned to sport and nonathletes to work.
Treatment with controlled exercise is a safe program that appears to improve PCS symptoms when compared with a no-treatment baseline. A randomized controlled study is warranted.
QUOTE FROM THE STUDY WORTH REMEMBERING:
Experimental animal data show that premature voluntary exercise within the first week after concussion impairs, whereas exercise performed 14-21 days after concussion improves, cognitive performance.
I think this study is very promising and seems to be the most effective treatment program I have been able to find when researching post-concussive syndrome for a new physical therapy patient I have with the condition. This is especially important because I was seeing him for balance/vestibular troubles but I really had my doubts that vestibular rehabilitation, which works great for BPPV, was going to work for him. So I did a literature review on the subject and blogged on a study that found vestibular rehabilitation exercises had no effect on dizziness in adults with post-concussive syndrome. Based in part on having read the book Spark, which was about the effects of exercise, particularly cardiovascular exercise and the brain, I thought the use of aerobic exercise for post-concussive syndrome made a lot of sense.
The treatment protocol in this study was to first test patients with what is called the Balke Protocol. They walked on a level treadmill at 3.3 mph for 1 minute, then added 2% incline, then increased the incline another 1% each minute until post-concussive symptoms were increased. The patients’ heart rate was then recorded and the test was stopped. The initial test was done to see what heart rate increased symptoms, so that the patients could exercise just below that level going forward.
The following exercise program was done on a treadmill with a target heart rate of 80% of the threshold heart rate, 5-6 days per week. Subjects were told to terminate the exercise at the first point of symptom exacerbation or if they reached their goal duration, which was same duration reached during the prior treadmill test. Balke Protocol treadmill tests were performed every 3 weeks until symptoms were no longer exacerbated by the test.
There were only 12 subjects in the study so results can’t be said to be universal. Treatment duration ranged from 11 to 112 days, with an average of 31.8. Exercise times on the treadmill increased from 9.75 minutes to 18.67 minutes. At follow up 3 months after the end of exercise 10 of the 12 subjects reported being symptom free, one still had cognitive and visual symptoms and one still had migraine headaches, but had a history of migraines prior to his injury.
Though still preliminary, overall these are very promising results for a problem that causes significant disabilities; for 15% of sufferers the symptoms can last for years or be permanent. And based on it, I’ll be putting aerobic exercise in my post-concussion physical therapy protocols going forward and will evaluate how well it works in real time.
As always, if you have any further questions or need for clarifications, please don’t hesitate to ask. Being aware that some of my blog ideas are contentious and occasionally a bit out of the field of my expertise, I encourage my readers to come forth with any questions/comments that are of interest or concern. Your comments are valued and welcomed.
Chad Reilly is a licensed physical therapist, located in North Phoenix, practicing science based medicine with treatment protocols unique and effective enough to proudly serve patients from Phoenix, Scottsdale, Mesa, Chandler, Tempe, Peoria, and Glendale.