A Preliminary Study of Subsymptom Threshold Exercise Training for Refractory Post-Concussion Syndrome.
Leddy, John J MD *+; Kozlowski, Karl PhD ++; Donnelly, James P PhD [S]; Pendergast, David R EdD [P]; Epstein, Leonard H PhD [//]; Willer, Barry PhD **
Clinical Journal of Sport Medicine.
20(1):21-27, January 2010.
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Objective: To evaluate the safety and effectiveness of subsymptom threshold exercise training for the treatment of post-concussion syndrome (PCS).
Design: Prospective case series.
Setting: University Sports Medicine Concussion Clinic.
Participants: Twelve refractory patients with PCS (6 athletes and 6 nonathletes).
Intervention: 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.
Results: 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.
Conclusions: 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.
(C) 2010 Lippincott Williams & Wilkins, Inc.