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 ± 27 bpm) and SBP (142 ± 6 mm Hg). After treatment, subjects exercised longer (9.75 ± 6.38 minutes to 18.67 ± 2.53 minutes, P
= .001) and achieved peak HR (179 ± 17 bpm) and SBP (156 ± 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 ± 8.7 vs 74.8 ± 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.