James MacDonald

Orthostatic Intolerance and Autonomic Dysfunction in Youth With Persistent Postconcussion Symptoms: A Head-Upright Tilt Table Study.

Objective:To explore head-upright tilt table (HUT) signs of autonomic dysfunction in a cohort of youth with persistent postconcussion symptoms (PCSs) that include light-headedness and to correlate repeat tilt table results with symptom improvements for those patients found to have postural tachycardia syndrome (POTS) on initial testing. Design:Prospective cohort design. Setting:Nationwide Childrens Hospital, Neurology Clinic. Participants:Thirty-four patients (13-18 years of age) with persistent PCSs. Main Outcome Measures:All patients underwent at least 1 tilt table test. The PCS Interview (PCS-I) and patient ratings of light-headedness and vertigo were used to measure symptom burden. Patients found to have POTS were asked to repeat tilt table testing when PCSs improved or 3 to 6 months after the initial test if symptoms persisted. Results:Twenty-four of the 34 (70.6%) patients had abnormal tilt table results with patients categorized as normal (n = 10), isolated syncope (n = 10), and POTS (n = 14). Patients with POTS had higher PCS-I scores than normal patients (P < 0.001) and higher ratings of light-headedness than both normal patients (P = 0.015) and syncope patients (P = 0.04). Twelve POTS patients underwent repeat tilt table testing, and 9 of 12 (75%) no longer met POTS diagnostic criteria. All patients with resolution of POTS had corresponding improvements in PCSs, including light-headedness and vertigo. Conclusions:Our study demonstrates a high rate of tilt table abnormalities among youth with persistent PCSs. Several patients with POTS had normalization of tilt table testing when PCSs improved. These findings warrant further research of autonomic dysfunction related to concussion. Clinical Relevance:Our study is the first to prospectively characterize autonomic dysfunction in patients with persistent PCSs using HUT testing and to show that the tilt test abnormalities normalize in some patients as PCSs improve.

Reliability of a Computerized Neurocognitive Test in Baseline Concussion Testing of High School Athletes.

Objective:Baseline assessments using computerized neurocognitive tests are frequently used in the management of sport-related concussions. Such testing is often done on an annual basis in a community setting. Reliability is a fundamental test characteristic that should be established for such tests. Our study examined the test–retest reliability of a computerized neurocognitive test in high school athletes over 1 year. Design:Repeated measures design. Setting:Two American high schools. Participants:High school athletes (N = 117) participating in American football or soccer during the 2011-2012 and 2012-2013 academic years. Interventions:All study participants completed 2 baseline computerized neurocognitive tests taken 1 year apart at their respective schools. The test measures performance on 4 cognitive tasks: identification speed (Attention), detection speed (Processing Speed), one card learning accuracy (Learning), and one back speed (Working Memory). Main Outcome Measures:Reliability was assessed by measuring the intraclass correlation coefficient (ICC) between the repeated measures of the 4 cognitive tasks. Pearson and Spearman correlation coefficients were calculated as a secondary outcome measure. Results:The measure for identification speed performed best (ICC = 0.672; 95% confidence interval, 0.559-0.760) and the measure for one card learning accuracy performed worst (ICC = 0.401; 95% confidence interval, 0.237-0.542). All tests had marginal or low reliability. Conclusions:In a population of high school athletes, computerized neurocognitive testing performed in a community setting demonstrated low to marginal test–retest reliability on baseline assessments 1 year apart. Further investigation should focus on (1) improving the reliability of individual tasks tested, (2) controlling for external factors that might affect test performance, and (3) identifying the ideal time interval to repeat baseline testing in high school athletes. Clinical Relevance:Computerized neurocognitive tests are used frequently in high school athletes, often within a model of baseline testing of asymptomatic individuals before the start of a sporting season. This study adds to the evidence that suggests in this population such testing may lack sufficient reliability to support clinical decision making.

Evaluation of a simple test of reaction time for baseline concussion testing in a population of high school athletes.

Objective:A common sequela of concussions is impaired reaction time. Computerized neurocognitive tests commonly measure reaction time. A simple clinical test for reaction time has been studied previously in college athletes; whether this test is valid and reliable when assessing younger athletes remains unknown. Our study examines the reliability and validity of this test in a population of high school athletes. Design:Cross-sectional study. Setting:Two American High Schools. Participants:High school athletes (N = 448) participating in American football or soccer during the academic years 2011 to 2012 and 2012 to 2013. Interventions:All study participants completed a computerized baseline neurocognitive assessment that included a measure of reaction time (RTcomp), in addition to a clinical measure of reaction time that assessed how far a standard measuring device would fall prior to the athlete catching it (RTclin). Main Outcome Measures:Validity was assessed by determining the correlation between RTclin and RTcomp. Reliability was assessed by measuring the intraclass correlation coefficients (ICCs) between the repeated measures of RTclin and RTcomp taken 1 year apart. Results:In the first year of study, RTclin and RTcomp were positively but weakly correlated (rs = 0.229, P < 0.001). In the second year, there was no significant correlation between RTclin and RTcomp (rs = 0.084, P = 0.084). Both RTclin [ICC = 0.608; 95% confidence interval (CI), 0.434-0.728] and RTcomp (ICC = 0.691; 95% CI, 0.554-0.786) had marginal reliability. Conclusions:In a population of high school athletes, RTclin had poor validity when compared with RTcomp as a standard. Both RTclin and RTcomp had marginal test-retest reliability. Before considering the clinical use of RTclin in the assessment of sport-related concussions sustained by high school athletes, the factors affecting reliability and validity should be investigated further. Clinical Relevance:Reaction time impairment commonly results from concussion and is among the most clinically important measures of the condition. The device evaluated in this study has previously been investigated as a reaction time measure in college athletes. This study investigates the clinical generalizability of the device in a younger population. Video Abstract:A video abstract showing how the RTclin device is used in practice is available as Supplemetal Digital Content 1, http://links.lww.com/JSM/A43.

The Reliability and Validity of a Pediatric Back Outcome Measure.

Objective:Young athletes not uncommonly complain of back pain. Many patient-reported outcome measures are used to evaluate back pain, but none have been designed specifically to assess young, athletic patients. The Micheli Functional Scale (MFS) was developed to measure impairment due to back pain in this population. This study examined the reliability, validity, and responsiveness of the MFS used in routine clinical assessments. Design:Retrospective Cohort Study. Setting:Pediatric sports medicine specialty clinic. Interventions:Patients presenting with a chief concern of back pain over 1 year (n = 93) were enrolled in the study. Study subjects were administered the MFS and the revised Oswestry Disability Index (ODI) at each visit as part of routine clinical care. Main Outcome Measures:Reliability of the MFS was assessed by calculating Cronbach alpha (&agr;). Concurrent validity was determined by measuring Spearman coefficient (rs) for the correlations between the MFS and ODI. Results:Ninety-three patients (50 female, 43 male), mean age 14.1 ± 2.3 years were enrolled and 242 clinic encounters (71 initial/171 follow-up visits) analyzed. The MFS had acceptable item reliability (&agr; = 0.786) and concurrent validity: the MFS and ODI were strongly and positively correlated [rs = 0.824 (P < 0.001)]. The MFS was comparatively more reliable and valid when used in follow-up versus initial visits. Conclusions:The MFS is a reliable and valid instrument in assessing young athletes with back pain, although the instrument has different performance characteristics on initial versus follow-up assessments. Further work is needed to refine the MFS to enhance the instruments reliability, validity, and responsiveness. Clinical Relevance:This study provides further insight into an outcome measure of clinical use in evaluating young athletes with back pain.

Athletes Doing Arabesques: Important Considerations in the Care of Young Dancers.

Dance is as much a sport as an art form. Sports medicine clinicians seeing dancers in their practice will need to be familiar with the unique characteristics of dance in order to provide proper care. Dance encompasses different forms, which vary in equipment and terminology. The epidemiology of dance injuries has historically focused on ballet, but there is increasing research on other dance forms. Lower extremity and back injuries predominate. Injury prevention, both primary and secondary, is at the heart of dance medicine. Primary prevention includes preseason conditioning, identifying risk factors for injury, and recognizing the female athlete triad. Secondary prevention includes a comprehensive approach to injury rehabilitation, an appreciation for the unique demands of dance, and an understanding of the particulars of the injury being treated. Dancers may have difficulty accessing medical care or following prescribed advice; the proactive clinician will anticipate these situations.