Faculty Bibliography

Research Objectives: Examine gender differences in self-reported postconcussion symptoms among individuals referred for neuropsychological services. Research has shown female gender is associated with increased susceptibility to emotional, physiological, sensory, and cognitive symptom clusters (King, 2014). Few studies have demonstrated which symptom cluster females are more likely to endorse. This study evaluates gender differences in symptomatology subsequent to various causes of concussion as research has shown this has implications for outcomes. Design: Retrospective study of adult concussion patients. Setting: Outpatient concussion center in an urban medical center. Participants: 100 patients (female = 59; mean age = 40.69 years) diagnosed with concussion or Post-Concussion Syndrome (PCS). Falls (33%), motor vehicle injuries (24%), and struck by an object (21%) were the top causes of injury. Interventions: Neuropsychological or psychological assessment. Main Outcome Measure(s): Sport Concussion Assessment Tool (SCAT 3). Results: Results indicated female concussion patients endorsed more physiological and sensory symptoms including nausea/vomiting (t(85.83)=-2.02, p <.05), dizziness (t(91) = -2.17, p <.05), balance problems (t(85.94) = -2.33, p <.05), sensitivity to light (t(91) = -3.18, p <.01 ), and sensitivity to noise (t(91) = -2.30, p <.05) than males. Additionally, females reported experiencing higher total numbers of symptoms (t(54.45)=-2.03, p <.05) and symptom severity (t(91) = -2.29, p <.05 ) than males. No gender differences were found with regard to cognitive, emotional, and sleep symptoms. Conclusions: A gender effect was demonstrated on several physiological and sensory concussion symptoms suggesting females to be more symptomatic than males. Results are consistent with previous findings indicating female athletes reported increased somatic symptoms postconcussion than male athletes. These findings can provide insight for rehabilitation specialists to develop more gender-specific approaches for treating female non-sport concussion patients

PURPOSE OF REVIEW: Post-traumatic headache (PTH) is a secondary headache disorder following traumatic brain injury. We sought to examine the recent literature on PTH and associated cognitive, psychiatric, and sleep conditions to understand the latest findings about the associated conditions and available screening tools, and to understand the available treatment options for PTH. RECENT FINDINGS: Up to one third of PTH patients may have depression and about one quarter may have insomnia. Anxiety and cognitive issues are also common. While there are few studies examining abortive medications for PTH, recent studies of preventive medications examine the efficacy of topiramate, and topiramate may be better than other oral preventive medications. Other currently investigated treatments include nerve blocks, onabotulinum toxin A, transmagnetic stimulation, and behavioral therapy (biofeedback). Due to an expanded focus on and knowledge of concussion and PTH, comorbid psychiatric, cognitive, and sleep issues have become more widely acknowledged and studied. However, more high-quality studies must be conducted to examine the underlying pathophysiology of PTH and associated symptoms and to determine the most effective abortive and preventive treatment options.

Surface-based cortical thickness (CT) analyses are increasingly being used to investigate variations in brain morphology across the spectrum of brain health, from neurotypical to neuropathological. An outstanding question is whether individual differences in cortical morphology, such as regionally increased or decreased CT, are associated with domain-specific performance deficits in healthy adults. Since CT studies are correlational, they cannot establish causality between brain morphology and cognitive performance. A direct comparison with classic lesion methods is needed to determine whether the regional specificity of CT-cognition correlations is similar to that observed in patients with brain lesions. We address this question by comparing the neuroanatomical overlap of effects when 1) whole brain vertex-wise CT is tested as a correlate of performance variability on a commonly used neuropsychological test of executive function, Trailmaking Test Part B (TMT-B), in healthy adults and 2) voxel-based lesion-symptom mapping (VBLSM) is used to map lesion location to performance decrements on the same task in patients with frontal lobe lesions. We found that reduced performance on the TMT-B was associated with increased CT in bilateral prefrontal regions in healthy adults and that results spatially overlapped in the left dorsomedial prefrontal cortex with findings from the VBLSM analysis in patients with frontal brain lesions. Findings indicate that variations in the structural integrity of the left dorsomedial prefrontal lobe, ranging from individual CT differences in healthy adults to structural lesions in patients with neurological disorders, are associated with poor performance on the TMT-B. These converging results suggest that the left dorsomedial prefrontal region houses a critical region for the complex processing demands of TMT-B, which include visuomotor tracking, sequencing, and cognitive flexibility.

BACKGROUND: The Sport Concussion Assessment Tool-3 (SCAT3) facilitates sideline clinical assessments of concussed athletes. Yet, there is little published research on clinically relevant metrics for the SCAT3 as a whole. PURPOSE: We documented the psychometric properties of the major SCAT3 components (symptoms, cognition, balance) and derived clinical decision criteria (ie, reliable change score cutoffs and normative conversation tables) for clinicians to apply to cases with and without available preinjury baseline data. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: High school and collegiate athletes (N = 2018) completed preseason baseline evaluations including the SCAT3. Re-evaluations of 166 injured athletes and 164 noninjured controls were performed within 24 hours of injury and at 8, 15, and 45 days after injury. Analyses focused on predictors of baseline performance, test-retest reliability, and sensitivity and specificity of the SCAT3 using either single postinjury cutoffs or reliable change index (RCI) criteria derived from this sample. RESULTS: Athlete sex, level of competition, attention-deficit/hyperactivity disorder (ADHD), learning disability (LD), and estimated verbal intellectual ability (but not concussion history) were associated with baseline scores on >/=1 SCAT3 components (small to moderate effect sizes). Female sex, high school level of competition (vs college), and ADHD were associated with higher baseline symptom ratings (d = 0.25-0.32). Male sex, ADHD, and LD were associated with lower baseline Standardized Assessment of Concussion (SAC) scores (d = 0.28-0.68). Male sex, high school level of competition, ADHD, and LD were associated with poorer baseline Balance Error Scoring System (BESS) performance (d = 0.14-0.26). After injury, the symptom checklist manifested the largest effect size at the 24-hour assessment (d = 1.52), with group differences diminished but statistically significant at day 8 (d = 0.39) and nonsignificant at day 15. Effect sizes for the SAC and BESS were small to moderate at 24 hours (SAC: d = -0.36; modified BESS: d = 0.46; full BESS: d = 0.51) and became nonsignificant at day 8 (SAC) and day 15 (BESS). Receiver operating characteristic curve analyses demonstrated a stronger discrimination for symptoms (area under the curve [AUC] = 0.86) than cognitive and balance measures (AUCs = 0.58 and 0.62, respectively), with comparable discrimination of each SCAT3 component using postinjury scores alone versus baseline-adjusted scores (P = .71-.90). Normative conversion tables and RCI criteria were created to facilitate the use of the SCAT3 both with and without baseline test results. CONCLUSION: Individual predictors should be taken into account when interpreting the SCAT3. The normative conversion tables and RCIs presented can be used to help interpret concussed athletes' performance both with and without baseline data, given the comparability of the 2 interpretative approaches.

OBJECTIVE: To determine the degree to which preinjury and acute postinjury psychosocial and injury-related variables predict symptom duration following sport-related concussion. METHODS: A total of 2,055 high school and collegiate athletes completed preseason evaluations. Concussed athletes (n = 127) repeated assessments serially (<24 hours and days 8, 15, and 45) postinjury. Cox proportional hazard modeling was used to predict concussive symptom duration (in days). Predictors considered included demographic and history variables; baseline psychological, neurocognitive, and balance functioning; acute injury characteristics; and postinjury clinical measures. RESULTS: Preinjury somatic symptom score (Brief Symptom Inventory-18 somatization scale) was the strongest premorbid predictor of symptom duration. Acute (24-hour) postconcussive symptom burden (Sport Concussion Assessment Tool-3 symptom severity) was the best injury-related predictor of recovery. These 2 predictors were moderately correlated (r = 0.51). Path analyses indicated that the relationship between preinjury somatization symptoms and symptom recovery was mediated by postinjury concussive symptoms. CONCLUSIONS: Preinjury somatization symptoms contribute to reported postconcussive symptom recovery via their influence on acute postconcussive symptoms. The findings highlight the relevance of premorbid psychological factors in postconcussive recovery, even in a healthy athlete sample relatively free of psychopathology or medical comorbidities. Future research should elucidate the neurobiopsychosocial mechanisms that explain the role of this individual difference variable in outcome following concussive injury.

As a 10-year follow up to our original study (Rabin, Barr, & Burton, 2005), we surveyed the test usage patterns of clinical neuropsychologists in the U.S and Canada. We expanded the original questionnaire to include additional cognitive and functional domains and to address current practice-related issues. Participants were randomly selected from the combined membership lists of the National Academy of Neuropsychology and the International Neuropsychological Society. Respondents were 512 doctorate-level members (25% usable response rate; 54% women) who had been practicing neuropsychology for 15 years on average. The Wechsler Adult Intelligence Scales, followed by the Wechsler Memory Scales, Trail Making Test, California Verbal Learning Test, and Wechsler Intelligence Scale for Children, were the most commonly used tests. These top five responses were identical and in the same order as those from 10 years ago. Participants respectively identified a lack of ecological validity and difficulty comparing the meaning of standardized scores across tests as the greatest challenges associated with the selection of neuropsychological instruments and interpretation of test data. Overall, we found great consistency in assessment practices over the 10-year period. We compare results to those of previous studies and discuss challenges and implications for neuropsychology.

OBJECTIVE: We evaluated how attention deficit-hyperactivity disorder (ADHD) and learning disability (LD) are associated with concussion history and performance on standard concussion assessment measures. Based on previous reports that developmental disorders are associated with increased injury proneness and poorer cognitive performance, we anticipated that ADHD and LD would be associated with increased history of concussion and poorer baseline performance on assessment measures. DESIGN: Cross-sectional study. SETTING: Clinical research center. PARTICIPANTS: The study sample aggregated data from two separate projects: the National Collegiate Athletic Association Concussion Study and Project Sideline. INTERVENTIONS: We analyzed preseason baseline data from 8056 high school and collegiate athletes (predominantly male football players) enrolled in prior studies of sport-related concussion. MAIN OUTCOME MEASURES: Measures included demographic/health history, symptoms, and cognitive performance. RESULTS: Attention deficit-hyperactivity disorder and LD were associated with 2.93 and 2.08 times the prevalence, respectively, of 3+ historical concussions (for comorbid ADHD/LD the prevalence ratio was 3.38). In players without histories of concussion, individuals with ADHD reported more baseline symptoms, and ADHD and LD were associated with poorer performance on baseline cognitive tests. Interactive effects were present between ADHD/LD status and concussion history for self-reported symptoms. CONCLUSIONS: Neurodevelopmental disorders and concussion history should be jointly considered in evaluating concussed players. CLINICAL RELEVANCE: Clinical judgments of self-reported symptoms and cognitive performance should be adjusted based on athletes' individual preinjury baselines or comparison with appropriate normative samples.

CONTEXT: Younger age has been hypothesized to be a risk factor for prolonged recovery after sport-related concussion, yet few studies have directly evaluated age differences in acute recovery. OBJECTIVE: To compare clinical recovery patterns for high school and collegiate athletes. DESIGN: Prospective cohort study. SETTING: Large, multicenter prospective sample collected from 1999-2003 in a sports medicine setting. SUBJECTS: Concussed athletes (n = 621; 545 males and 76 females) and uninjured controls (n = 150) participating in high school and collegiate contact and collision sports (79% in football, 15.7% in soccer, and the remainder in lacrosse or ice hockey). MAIN OUTCOME MEASURE(S): Participants underwent evaluation of symptoms (Graded Symptom Checklist), cognition (Standardized Assessment of Concussion, paper-and-pencil neuropsychological tests), and postural stability (Balance Error Scoring System). Athletes were evaluated preinjury and followed serially at several time points after concussive injury: immediately, 3 hours postinjury, and at days 1, 2, 3, 5, 7, and 45 or 90 (with neuropsychological measures administered at baseline and 3 postinjury time points). RESULTS: Comparisons of concussed high school and collegiate athletes with uninjured controls suggested that high school athletes took 1 to 2 days longer to recover on a cognitive (Standardized Assessment of Concussion) measure. Comparisons with the control group on other measures (symptoms, balance) as well as direct comparisons between concussed high school and collegiate samples revealed no differences in the recovery courses between the high school and collegiate groups on any measure. Group-level recovery occurred at or before 7 days postinjury on all assessment metrics. CONCLUSIONS: The findings suggest no clinically significant age differences exist in recovery after sport-related concussion, and therefore, separate injury-management protocols are not needed for high school and collegiate athletes.