Rehabilitation of Concussion and Persistent Postconcussive Symptoms.

Concussion and persistent postconcussive symptoms (PPCS) are encountered by clinicians in sports medicine, pediatrics, neurology, physiatry, emergency medicine, and primary care. Clinical management may require a multidisciplinary approach. This article presents a structured method for the diagnosis of concussion and PPCS in the outpatient setting, which includes a history, physical examination, and additional tests as clinically indicated to help identify underlying symptom generators. Treatment for concussion and PPCS should be individualized, based on predominant signs and symptoms, and can include subsymptom threshold aerobic exercise, cervical physical therapy, vestibulo-ocular rehabilitation, behavioral and cognitive psychotherapy, and some symptom-specific pharmacological therapies.

Symptoms upon postural change and orthostatic hypotension in adolescents with concussion.

Objective: Concussion is associated with dysautonomia, altered blood pressure (BP) control, and may cause Orthostatic Hypotension (OH). We measured prevalence of OH using the 1-minute supine-to-standing OH Test in adolescents with concussion and controls.Participants: Adolescents within 10 days of injury (Concussion Group, n = 297, 15.0 ± 1.7 years, 59% male) were compared with controls (Control Group, n = 214, 15.0 ± 1.5 years, 58% male).Methods: BP, heart rate (HR), and complaints of lightheadedness/dizziness were measured after 2-minute supine and 1-minute standing. Control Group was assessed once. Concussion Group was assessed twice; (1) initial visit (mean 6.0 ± 3 days-since-injury) and (2) after clinical recovery (mean 46.3 ± 42 days-since-injury).Results: Initial visit; Concussion Group reported feeling lightheaded/dizzy on postural change more often than the Control Group (37% vs 4%, p < .001) but did not differ in meeting standard OH criteria (3% vs 5%, p = .32). Experiencing symptoms did not correlate with meeting OH criteria, but correlated with abnormal vestibulo-ocular reflex. After clinical recovery; Concussion Group did not differ in experiencing lightheaded/dizziness on postural change than controls (4%, p = .65).Conclusion: Adolescents commonly experience orthostatic intolerance after concussion without meeting the standard criteria for OH.

Blunted Cardiac Parasympathetic Activation in Student Athletes With a Remote History of Concussion: A Pilot Study.

Introduction: Blunted cardiac autonomic nervous system (ANS) responses, quantified using heart rate variability (HRV), have been reported after sport-related concussion (SRC). Research suggests this persists beyond clinical recovery. This study compared cardiac parasympathetic responses in student athletes with a remote history of SRC (> 1-year ago, Concussion History: CH) with those who reported no lifetime history of SRC (Concussion Naïve: CN). Design: Retrospective nested case-control. Setting: University laboratory. Patients or Other Participants: CH (n = 9, 18.3 ± 2 years, 44% male, median 2 years since injury) were student athletes with a remote history of concussion(s) from more than 1 year ago. CN (n = 21, 16.7 ± 3 years, 67% male) were student athletes with no lifetime history of concussion. Exclusion criteria included taking medications that could affect ANS function, history of concussion within the past year, persistent concussion symptoms, lifetime history of moderate to severe brain injury, and lifetime history of more than 3 concussions. Material and Methods: Participants performed the Face Cooling (FC) test for 3-min after 10-min of supine rest while wearing a 3-lead electrocardiogram in a controlled environment. Outcome Measures: Heart rate (HR), R-R interval (RRI), root mean square of the successive differences (RMSSD) of RRI, high frequency (HF) and low frequency to HF (LF:HF) ratios. Results: At baseline, CH had a lower resting HR than CN (62.3 ± 11 bpm vs. 72.9 ± 12, p = 0.034). CH had a different HR response to FC than CN (+8.9% change from baseline in CH vs. -7.5% in CN, p = 0.010). CH also had a smaller RMSSD increase to FC than CN (+31.8% change from baseline in CH vs. +121.8% in CN, p = 0.048). There were no significant group differences over time in RRI (p = 0.106), HF (p = 0.550) or LF:HF ratio (p = 0.053). Conclusion: Asymptomatic student athletes with a remote history of concussion had a blunted cardiac parasympathetic response to FC when compared with athletes with no lifetime history of concussion. These data suggest that an impaired autonomic response to a physiological stressor persists after clinical recovery from SRC for longer than previously reported.

Postexercise Slowing on the King-Devick Test and Longer Recovery From Sport-Related Concussion in Adolescents: A Validation Study.

CONTEXT: The King-Devick (KD) test is a rapid number-reading test that has emerging use in the assessment of sport-related concussion (SRC). Previous research suggested that healthy individuals and patients with acute concussions who had shorter recovery times (<3 weeks) demonstrated a learning effect on the KD test after mild to moderate exertion, whereas patients with longer recovery times did not. OBJECTIVE: To assess if the absence of postexertional improvement on the KD test within 10 days of concussive head injury was associated with a longer duration of recovery. DESIGN: Prospective cohort study. SETTING: University concussion-management clinics. PATIENTS OR OTHER PARTICIPANTS: Male and female adolescent athletes (n = 99, aged 13-18 years) presenting within 10 days of SRC. MAIN OUTCOME MEASURE(S): The KD test was administered before and after the Buffalo Concussion Treadmill Test (BCTT). Days from injury to recovery, with recovery defined as being asymptomatic, confirmed by the assessment of a physician who was blinded to the treatment group, and the return of normal exercise tolerance on the BCTT were recorded. RESULTS: Participants with postexertional slowing (PES group, n = 33) had a longer duration of recovery (17 days versus 13.5 days, P = .033) than participants without PES (no-PES group, n = 66). At any clinic visit, PES was also associated with a relative risk of 2.36 (95% confidence interval = 1.55, 3.61; P < .001) of not recovering within the following week. CONCLUSIONS: The current study validates our prior work showing that acutely concussed adolescents who did not display the typical learning effect on the KD test after the BCTT took longer to recover from SRC than those who exhibited the typical learning effect.

Comparison of Rest to Aerobic Exercise and Placebo-like Treatment of Acute Sport-Related Concussion in Male and Female Adolescents.

OBJECTIVE: To compare a sample of adolescents with sport-related concussion (SRC) who were prescribed rest with 2 arms of a randomized controlled trial comparing aerobic exercise with placebo-like stretching. We also compared sex differences across the 3 approaches to treatment. DESIGN: Quasi-experimental trial. SETTING: University concussion management clinics. PARTICIPANTS: Adolescent athletes (aged 13-18 years) presenting within 10 days of SRC (mean, 5 days after injury) received a recommendation for rest (rest group [RG], n=48, 15.4±1y, 25% female). Their outcomes were compared with matched samples of adolescents assigned to aerobic exercise (exercise group [EG], n=52, 15.3±2y, 46% female) or placebo-like stretching (placebo group [PG], n=51, 15.4±2y, 47% female) (N=151). MAIN OUTCOME MEASURES: The primary outcome was median days from injury to recovery. The secondary outcome was proportion classified as normal recovery (<30d) or delayed recovery (≥30d). RESULTS: The RG recovered in 16 days (interquartile range, 9.25-23.25d), which was significantly delayed (P=.020) compared with EG (13d; interquartile range, 10-18.5d). The PG recovered in 17 days (interquartile range, 13-23d). Four percent of the EG, 14% of the PG, and 13% of the RG had delayed recovery (P=.190). There was no difference in recovery time or delayed recovery between male participants and female participants across groups. Female participants prescribed rest experienced an increase in symptoms vs the other groups (P=.013). CONCLUSION: Relative rest and a placebo-like stretching program were very similar in days to recovery and symptom improvement pattern after SRC. Both conditions were less effective than subsymptom threshold aerobic exercise. Female adolescents appear to be susceptible to symptom increase when prescribed rest.

The Predictive Capacity of the Buffalo Concussion Treadmill Test After Sport-Related Concussion in Adolescents.

The Buffalo Concussion Treadmill Test (BCTT) identifies the heart rate threshold (HRt) of exercise tolerance in concussed patients. A previous study found that an absolute HRt of < 135 bpm was associated with prolonged recovery (>30 days) from sport-related concussion (SRC). In this study, we assessed the relationship of ΔHR (difference between resting HR and HRt) and recovery from SRC. Using a retrospective cohort design, we compared acutely (<10 days since injury) concussed adolescents who were prescribed either (1) relative rest (RG, n = 27, 15.2 ± 1 years, 33% female, median 17 days to recovery, ΔHR = 69.6 ± 28 bpm), (2) a placebo-stretching program (PG, n = 51, 15.4 ± 2 years, 49% female, median 17 days to recovery, ΔHR = 60.9 ± 22 bpm), or (3) sub-threshold aerobic exercise (AG, n = 52, 15.3 ± 2 years, 46% female, median 13 days to recovery, ΔHR = 62.4 ± 26 bpm). Linear regression showed that ΔHR significantly correlated with duration of clinical recovery for RG (p = 0.012, R 2 = 0.228) and PG (p = 0.011, R 2 = 0.126) but not for AG (p = 0.084, R 2 = 0.059). ΔHR values were significantly lower in participants with prolonged recovery (>30 days) in RG (p = 0.01) and PG (p = 0.04). A ΔHR of ≤50 bpm on the BCTT is 73% sensitive and 78% specific for predicting prolonged recovery in concussed adolescents who were prescribed the current standard of care (i.e., cognitive and physical rest).

Active recovery from concussion.

PURPOSE OF REVIEW: Recent studies are challenging the utility of prolonged rest as treatment for concussion and postconcussion syndrome (PCS). The purpose of this paper is to review the evidence for active recovery from concussion and PCS. RECENT FINDINGS: Emerging data identify the central role of autonomic nervous system (ANS) dysfunction in concussion pathophysiology. The exercise intolerance demonstrated by athletes after sport-related concussion may be related to abnormal ANS regulation of cerebral blood flow. As aerobic exercise training improves ANS function, sub-symptom threshold exercise treatment is potentially therapeutic for concussion. A systematic assessment of exercise tolerance using the Buffalo Concussion Treadmill Test has been safely employed to prescribe a progressive, individualized subthreshold aerobic exercise treatment program that can return patients to sport and work. Multiple studies are demonstrating the efficacy of an active approach to concussion management. SUMMARY: Sustained rest from all activities after concussion, so-called 'cocoon therapy', is not beneficial to recovery. Evidence supports the safety, tolerability, and efficacy of controlled sub-symptom threshold aerobic exercise treatment for PCS patients. Further study should determine the efficacy and optimal timing, dose, and duration of subthreshold aerobic exercise treatment acutely after concussion because early intervention has potential to prevent PCS.