Safety and Prognostic Utility of Provocative Exercise Testing in Acutely Concussed Adolescents: A Randomized Trial.

OBJECTIVE: To evaluate (1) systematic assessment of exercise tolerance in adolescents shortly after sport-related concussion (SRC) and (2) the prognostic utility of such assessment. DESIGN: Prospective randomized controlled trial. SETTING: University and community sports medicine centers. PARTICIPANTS: Adolescents with SRC (1-9 days from injury). Sixty-five were randomized and 54 completed the study (mean age 15 years, 4 days after injury). INTERVENTIONS: Buffalo Concussion Treadmill Test (BCTT, n = 27) or not (controls, n = 27) on visit day #1. Heart rate threshold (HRt) at symptom exacerbation represented level of exercise tolerance. Participants reported symptoms daily for 14 days and then had follow-up BCTT (n = 54). Recovery was defined as returning to normal level of symptoms and exercise tolerance, verified by independent physician examination. MAIN OUTCOME MEASURES: Days to recovery and typical (≤21 days) versus prolonged recovery (>21 days). Mixed effects linear models and linear regression techniques examined symptom reports and time to recovery. Linear regression assessed the association of HRt with recovery time. RESULTS: Days to recovery (P = 0.7060) and typical versus prolonged recovery (P = 0.1195) were not significantly different between groups. Symptom severity scores decreased in both groups over 14 days (P < 0.0001), were similar (P = 0.2984), and did not significantly increase the day after the BCTT (P = 0.1960). Lower HRt on visit day #1 was strongly associated with prolonged recovery time (P = 0.0032). CONCLUSIONS: Systematic evaluation of exercise tolerance using the BCTT within 1 week after SRC did not affect recovery. The degree of early exercise intolerance after SRC was important for prognosis. This has implications for school academic and team preparation.

Brain or strain? Symptoms alone do not distinguish physiologic concussion from cervical/vestibular injury.

OBJECTIVE: To compare symptoms in patients with physiologic postconcussion disorder (PCD) versus cervicogenic/vestibular PCD. We hypothesized that most symptoms would not be equivalent. In particular, we hypothesized that cognitive symptoms would be more often associated with physiologic PCD. DESIGN: Retrospective review of symptom reports from patients who completed a 22-item symptom questionnaire. SETTING: University-based concussion clinic. PATIENTS: Convenience sample of 128 patients who had symptoms after head injury for more than 3 weeks and who had provocative treadmill exercise testing. INDEPENDENT VARIABLES: Subjects were classified as either physiologic PCD (abnormal treadmill performance and a normal cervical/vestibular physical examination) or cervicogenic/vestibular PCD (CGV, normal treadmill performance, and an abnormal cervical/vestibular physical examination). MAIN OUTCOME MEASURES: Self-reported symptoms. Univariate and multivariate methods, including t tests, tests of equivalence, a logistic regression model, k-nearest neighbor analysis, multidimensional scaling, and principle components analysis were used to see whether symptoms could distinguish PCD from CGV. RESULTS: None of the statistical methods used to analyze self-reported symptoms was able to adequately distinguish patients with PCD from patients with CGV. CONCLUSIONS: Symptoms after head injury, including cognitive symptoms, have traditionally been ascribed to brain injury, but they do not reliably discriminate between physiologic PCD and cervicogenic/vestibular PCD. Clinicians should consider specific testing of exercise tolerance and perform a physical examination of the cervical spine and the vestibular/ocular systems to determine the etiology of postconcussion symptoms. CLINICAL RELEVANCE: Symptoms after head injury, including cognitive symptoms, do not discriminate between concussion and cervical/vestibular injury.

Behavioral health symptoms associated with chronic traumatic encephalopathy: a critical review of the literature and recommendations for treatment and research.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative syndrome that has been linked to serious psychiatric symptoms, including depression, aggression, and suicidal behavior. This review critically examines the extant research on the behavioral manifestations of CTE and concludes that the paucity of longitudinal prospective studies on CTE, combined with a lack of research-accepted diagnostic criteria for identifying individuals who are considered at risk for CTE, makes it difficult to reliably establish a causal relationship between CTE and the onset of behavioral health problems. Selection and reporting bias and inconsistency in data collection methods are other concerns. To advance the field, there is a critical need for more empirical research on the behavioral manifestations of CTE. Recommendations and intervention models are also discussed.

Enteral baclofen withdrawal managed with intravenous dexmedetomidine: A case report.

PURPOSE: Acute enteral baclofen withdrawal can be clinically severe if not identified and managed appropriately. Treatment of baclofen withdrawal includes supportive care and reinitiation of baclofen. There are limited pharmacotherapeutic interventions available to manage symptoms of acute enteral baclofen withdrawal, especially in nonintubated patients. SUMMARY: We describe a 61-year-old Caucasian male with a past medical history of chronic back pain and spinal stenosis who was admitted to the medical intensive care unit with confusion, insomnia, agitation, delirium, and auditory and visual hallucinations. For control of agitation, the patient was administered 10 mg of i.v. haloperidol, 1 mg of i.v. lorazepam, and 14 mg of i.v. midazolam, with minimal improvement noted; therefore, dexmedetomidine was initiated, which led to clinical resolution of his symptoms. Upon further investigation it was determined that the patient was taking approximately 10 baclofen 20-mg tablets a day. According to his pharmacy records, he had filled prescriptions for a total of 738 baclofen tablets in the previous 12 weeks. The patient's presentation and sudden discontinuation of high-dose baclofen led to a diagnosis of baclofen withdrawal. Baclofen was subsequently restarted, and dexmedetomidine was weaned over 36 hours. CONCLUSION: Dexmedetomidine controlled this patient's agitation and delirium without suppressing his respiratory drive and should be considered for management of acute enteral baclofen withdrawal.

Self-reported concussion history: impact of providing a definition of concussion.

BACKGROUND: In recent years, the understanding of concussion has evolved in the research and medical communities to include more subtle and transient symptoms. The accepted definition of concussion in these communities has reflected this change. However, it is unclear whether this shift is also reflected in the understanding of the athletic community. WHAT IS KNOWN ABOUT THE SUBJECT: Self-reported concussion history is an inaccurate assessment of someone's lifetime exposure to concussive brain trauma. However, unfortunately, in many cases it is the only available tool. HYPOTHESIS/PURPOSE: We hypothesize that athletes' self-reported concussion histories will be significantly greater after reading them the current definition of concussion, relative to the reporting when no definition was provided. An increase from baseline to post-definition response will suggest that athletes are unaware of the currently accepted medical definition. STUDY DESIGN: Cross-sectional study of 472 current and former athletes. METHODS: Investigators conducted structured telephone interviews with current and former athletes between January 2010 and January 2013, asking participants to report how many concussions they had received in their lives. Interviewers then read participants a current definition of concussion, and asked them to re-estimate based on that definition. RESULTS: THE TWO ESTIMATES WERE SIGNIFICANTLY DIFFERENT (WILCOXON SIGNED RANK TEST: z=15.636, P<0.001). Comparison of the baseline and post-definition medians (7 and 15, respectively) indicated that the post-definition estimate was approximately twice the baseline. Follow-up analyses indicated that this effect was consistent across all levels of competition examined and across type of sport (contact versus non-contact). CONCLUSION: Our results indicate that athletes' current understandings of concussions are not consistent with a currently accepted medical definition. We strongly recommend that clinicians and researchers preface requests for self-reported concussion history with a definition. In addition, it is extremely important that researchers report the definition they used in published manuscripts of their work. WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE: Our study shows that unprompted reporting of concussion history produces results that are significantly different from those provided after a definition has been given, suggesting one possible mechanism to improve the reliability of self-reported concussion history across multiple individuals.