Relationship Between Short Sleep Duration and Preseason Concussion Testing.

OBJECTIVE: Baseline, preseason assessment of cognition, symptoms, and balance has been recommended as part of a comprehensive sport concussion management program. We examined the relationship between sleep and baseline test results. We hypothesized that adolescents who slept fewer hours the night before would report more symptoms and perform more poorly on cognitive testing than students who had a full night sleep. DESIGN: Cross-sectional observation study. SETTING: Preseason concussion testing for high school athletes. PARTICIPANTS: A large sample (n = 2928) of student athletes from Maine, USA, between the ages of 13 and 18 years completed preseason testing. Participants with developmental problems, a history of treatment for neurological or psychiatric problems, recent concussion, or 3 or more prior concussions were excluded. ASSESSMENT OF RISK FACTORS: Athletes were divided into 4 groups based on their sleep duration the night before testing. MAIN OUTCOME MEASURES: Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT; ImPACT Applications, Inc, Pittsburgh, PA) cognitive composite scores and the embedded Post-Concussion Symptom Scale. RESULTS: Sleep was not related to any ImPACT cognitive composite score, after covarying for age and controlling for multiple comparisons. In contrast, there were sleep duration, sex, and sleep duration by sex effects on the Post-Concussion Symptom Scale. The effect of sleep duration on symptom reporting was more pronounced in girls. Supplementary analyses suggested that sleep insufficiency was associated with a diverse array of postconcussion-like symptoms. CONCLUSIONS: Poor sleep the night before baseline or postinjury testing may be an important confound when assessing postconcussion symptoms. Girls may be more vulnerable to experiencing and reporting symptoms following insufficient sleep. CLINICAL RELEVANCE: Clinicians should routinely ask how the athlete slept the night before preseason baseline testing and consider deferring the symptom assessment or later retesting athletes who slept poorly.

High School Athletes With ADHD and Learning Difficulties Have a Greater Lifetime Concussion History.

Objective: Examine lifetime history of concussions in adolescents who have developmental problems in comparison with those with no developmental problems. Method: Thirty-two thousand four hundred eighty-seven adolescent athletes completed baseline/pre-season evaluations. Based on self-reported histories, athletes were divided into four groups: ADHD only, ADHD and learning difficulties (LD), LD only, and controls. Results: Athletes with ADHD, LD, or ADHD plus LD reported a greater prevalence of prior concussions than athletes without these developmental conditions (ps < .05). When adjusting for sex differences in concussion prevalence rates (boys are greater than girls), there was an increase in prevalence of prior injuries in those with ADHD, and ADHD plus learning difficulties compared with those with LD only. This pattern was found for both girls and boys. There was no additive effect of having both conditions. Conclusion: Developmental conditions in adolescent athletes, such as ADHD and learning difficulties, are associated with a greater prevalence rate of prior concussion.

Factor Structure of ImPACT® in Adolescent Student Athletes.

OBJECTIVE: ImPACT® (Immediate Post-Concussion Assessment and Cognitive Testing) is a computerized neuropsychological screening battery, which is widely used to measure the acute effects of sport-related concussion and to monitor recovery from injury. This study examined the factor structure of ImPACT® in several samples of high school student athletes. We hypothesized that a 2-factor structure would be present in all samples. METHOD: A sample of 4,809 adolescent student athletes was included, and subgroups with a history of treatment for headaches or a self-reported history of learning problems or attention-deficit hyperactivity disorder were analyzed separately. Exploratory principal axis factor analyses with Promax rotations were used. RESULTS: As hypothesized, both the combination of Verbal Memory and Visual Memory Composite scores loaded on one (Memory) factor, while Visual Motor Speed and Reaction Time loaded on a different (Speed) factor, in the total sample and in all subgroups. CONCLUSION: These results provide reasonably compelling evidence, across multiple samples, which ImPACT® measures 2 distinct factors: memory and speed.

Concussion History in Adolescent Athletes with Attention-Deficit Hyperactivity Disorder.

Little is known about the rate of concussions in adolescents with attention-deficit hyperactivity disorder (ADHD). We hypothesized that high school athletes with ADHD would report a greater history of concussion than students without ADHD. A total of 6529 adolescent and young adult student athletes, between the ages of 13 and 19 years (mean, 15.9; standard deviation, 1.3), completed a preseason health survey in 2010. Of those with ADHD, 26.1% reported a history of one or more concussions, compared to 17.1% of those without ADHD (p<0.00001; odds ratio [OR], 1.71). Stratified by gender, 27.0% of boys with ADHD reported a history of one or more concussions, compared to 20.0% of boys without ADHD (p<0.004; OR, 1.48), and 23.6% of girls with ADHD reported a history of one or more concussions, compared to 13.6% of girls without ADHD (p<0.003; OR, 1.97). Of those with ADHD, 9.8% reported a history of two or more concussions, compared to 5.5% of those without ADHD (p<0.0003; OR, 1.87). Stratified by gender, 10.0% of boys with ADHD reported a history of two or more concussions, compared to 6.7% of boys without ADHD (p<0.033; OR, 1.54), and 9.1% of girls with ADHD reported a history of two or more concussions, compared to 3.8% of girls without ADHD (p<0.006; OR, 2.51). In this large-scale, retrospective survey study, boys and girls with ADHD were significantly more likely to report a history of concussion. Additional research is needed to determine whether students with ADHD are more susceptible to injury (i.e., have a lower threshold) or have different recovery trajectories.

Sex Differences and Self-Reported Attention Problems During Baseline Concussion Testing.

Amateur athletic programs often use computerized cognitive testing as part of their concussion management programs. There is evidence that athletes with preexisting attention problems will have worse cognitive performance and more symptoms at baseline testing. The purpose of this study was to examine whether attention problems affect assessments differently for male and female athletes. Participants were drawn from a database that included 6,840 adolescents from Maine who completed Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) at baseline (primary outcome measure). The final sample included 249 boys and 100 girls with self-reported attention problems. Each participant was individually matched for sex, age, number of past concussions, and sport to a control participant (249 boys, 100 girls). Boys with attention problems had worse reaction time than boys without attention problems. Girls with attention problems had worse visual-motor speed than girls without attention problems. Boys with attention problems reported more total symptoms, including more cognitive-sensory and sleep-arousal symptoms, compared with boys without attention problems. Girls with attention problems reported more cognitive-sensory, sleep-arousal, and affective symptoms than girls without attention problems. When considering the assessment, management, and outcome from concussions in adolescent athletes, it is important to consider both sex and preinjury attention problems regarding cognitive test results and symptom reporting.

Factors Associated With Concussion-like Symptom Reporting in High School Athletes.

IMPORTANCE: Every state in the United States has passed legislation for sport-related concussion, making this health issue important for physicians and other health care professionals. Safely returning athletes to sport after concussion relies on accurately determining when their symptoms resolve. OBJECTIVE: To evaluate baseline concussion-like symptom reporting in uninjured adolescent student athletes. DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional, observational study, we studied 31 958 high school athletes from Maine with no concussion in the past 6 months who completed a preseason baseline testing program between 2009 and 2013. RESULTS: Symptom reporting was more common in girls than boys. Most students with preexisting conditions reported one or more symptoms (60%-82% of boys and 73%-97% of girls). Nineteen percent of boys and 28% of girls reported having a symptom burden resembling an International Classification of Diseases, 10th Revision (ICD-10) diagnosis of postconcussional syndrome (PCS). Students with preexisting conditions were even more likely to endorse a symptom burden that resembled PCS (21%-47% for boys and 33%-72% for girls). Prior treatment of a psychiatric condition was the strongest independent predictor for symptom reporting in boys, followed by a history of migraines. For girls, the strongest independent predictors were prior treatment of a psychiatric condition or substance abuse and attention-deficit/hyperactivity disorder. The weakest independent predictor of symptoms for both sexes was history of prior concussions. CONCLUSIONS AND RELEVANCE: In the absence of a recent concussion, symptom reporting is related to sex and preexisting conditions. Consideration of sex and preexisting health conditions can help prevent misinterpretation of symptoms in student athletes who sustain a concussion.

Experience-dependent visual cue recalibration based on discrepancies between visual and haptic percepts.

We studied the hypothesis that observers can recalibrate their visual percepts when visual and haptic (touch) cues are discordant and the haptic information is judged to be reliable. Using a novel visuo-haptic virtual reality environment, we conducted a set of experiments in which subjects interacted with scenes consisting of two fronto-parallel surfaces. Subjects judged the distance between the two surfaces based on two perceptual cues: a visual stereo cue obtained when viewing the scene binocularly and a haptic cue obtained when subjects grasped the two surfaces between their thumb and index fingers. Visual and haptic cues regarding the scene were manipulated independently so that they could either be consistent or inconsistent. Experiment 1 explored the effect of visuo-haptic inconsistencies on depth-from-stereo estimates. Our findings suggest that when stereo and haptic cues are inconsistent, subjects recalibrate their interpretations of the visual stereo cue so that depth-from-stereo percepts are in greater agreement with depth-from-haptic percepts. In Experiment 2 the visuo-haptic discrepancy took a different form when the two surfaces were near the subject than when they were far from the subject. The results indicate that subjects recalibrated their interpretations of the stereo cue in a context-sensitive manner that depended on viewing distance, thereby making them more consistent with depth-from-haptic estimates at all viewing distances. Together these findings suggest that observers' visual and haptic percepts are tightly coupled in the sense that haptic percepts provide a standard to which visual percepts can be recalibrated when the visual percepts are deemed to be erroneous.

Multiple prior concussions are associated with symptoms in high school athletes.

OBJECTIVES: The purpose of this study was to evaluate the association of prior concussion on baseline computerized neurocognitive testing in a large cohort of high school athletes. METHODS: This is a retrospective cohort study of student athletes from 49 Maine High Schools in 2010 who underwent baseline computerized neurocognitive evaluation with Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®). As part of the ImPACT®, subjects reported a prior history of concussion as well as demographic information and a symptom questionnaire. We used linear regression to evaluate the association of prior concussion with baseline: (1) ImPACT® composite scores; and (2) symptom scores. RESULTS: Six thousand seventy-five subjects were included in the study, of whom 57% were boys. The majority of student athletes (85.3%) reported no prior history of concussion while 4.6% reported having sustained two or more prior concussions. On simple linear regression, increasing number of concussions was related to worse performance in verbal memory (P = 0.039) and greater symptoms scores (P < 0.001). On multivariate modeling, only the association with baseline symptoms remained (P < 0.001). Other factors associated with baseline symptom reporting in the multivariate model included mental health history, headache/migraine history, gender, developmental and/or learning problems, and number of prior concussions. INTERPRETATION: In this large-scale, retrospective survey study, history of multiple prior concussions was associated with higher symptom burden but not baseline computerized neurocognitive testing. The association between baseline symptom reporting and clinical and demographic factors was greater than the association with a history of multiple concussions.