Person:

Iverson, Grant

Introduction: Current management of concussion consists of early education, rest until symptom free, with gradual return to school and physical activity protocols. Although this management strategy is effective for most youth who sustain a concussion, it is not an appropriate strategy for youth with persistent postconcussion symptoms. Prolonged rest and periods of restricted activity may place youth at risk for secondary issues and contribute to the chronicity of postconcussion symptoms. The purpose of this study is to evaluate the efficacy of an active rehabilitation protocol for youth who are slow to recover from concussion. It is hypothesised that an active rehabilitation intervention can reduce persistent postconcussion symptoms, improve function and facilitate return to activity. This article describes the research protocol. Methods and analysis This is a randomised clinical trial with blinded outcome measurement. Participants will be recruited and randomly assigned to 1 of 2 treatment groups, an active rehabilitation intervention or a standard care education group. Both groups will receive standard care education. However, the active rehabilitation group will participate in an additional low-intensity exercise programme consisting of aerobic, coordination and visualisation exercises. Both the active rehabilitation and the standard care education interventions will be 6 weeks in duration. The primary outcome measure is postconcussion symptoms. Secondary outcome measures include functional recovery (cognitive, motor, psychosocial and emotional functioning) and return to activity. Outcome measures will be administered preintervention and postintervention. The primary outcome measure will also be repeated 2 weeks into the intervention period. Ethics and dissemination This study has been approved by the Holland Bloorview Kids Rehabilitation Hospital research ethics board (REB # 13-459). The findings from this study will be shared with the general public, sport associations, relevant brain injury organisations and healthcare professionals. Trial registration number NCT02257749.

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.

It is common for some healthy older adults to obtain low test scores when a battery of neuropsychological tests is administered, which increases the risk of the clinician misdiagnosing cognitive impairment. Thus, base rates of healthy individuals’ low scores are required to more accurately interpret neuropsychological results. At present, this information is not available for the German version of the Consortium to Establish a Registry for Alzheimer’s Disease-Neuropsychological Assessment Battery (CERAD-NAB), a frequently used battery in the USA and in German-speaking Europe. This study aimed to determine the base rates of low scores for the CERAD-NAB and to tabulate a summary figure of cut-off scores and numbers of low scores to aid in clinical decision making. The base rates of low scores on the ten German CERAD-NAB subscores were calculated from the German CERAD-NAB normative sample (N = 1,081) using six different cut-off scores (i.e., 1st, 2.5th, 7th, 10th, 16th, and 25th percentile). Results indicate that high percentages of one or more “abnormal” scores were obtained, irrespective of the cut-off criterion. For example, 60.6 % of the normative sample obtained one or more scores at or below the 10th percentile. These findings illustrate the importance of considering the prevalence of low scores in healthy individuals. The summary figure of CERAD-NAB base rates is an important supplement for test interpretation and can be used to improve the diagnostic accuracy of neurocognitive disorders. Electronic supplementary material The online version of this article (doi:10.1007/s00406-014-0571-z) contains supplementary material, which is available to authorized users.

Abstract Background: In addition to experiencing traumatic events while deployed in a combat environment, there are other factors that contribute to the development of posttraumatic stress disorder (PTSD) in military service members. This study explored the contribution of genetics, childhood environment, prior trauma, psychological, cognitive, and deployment factors to the development of traumatic stress following deployment. Methods: Both pre‐ and postdeployment data on 231 of 458 soldiers were analyzed. Postdeployment assessments occurred within 30 days from returning stateside and included a battery of psychological health, medical history, and demographic questionnaires; neurocognitive tests; and blood serum for the D2 dopamine receptor (DRD2), apolipoprotein E (APOE), and brain‐derived neurotropic factor (BDNF) genes. Results: Soldiers who screened positive for traumatic stress at postdeployment had significantly higher scores in depression (d = 1.91), anxiety (d = 1.61), poor sleep quality (d = 0.92), postconcussion symptoms (d = 2.21), alcohol use (d = 0.63), traumatic life events (d = 0.42), and combat exposure (d = 0.91). BDNF Val66 Met genotype was significantly associated with risk for sustaining a mild traumatic brain injury (mTBI) and screening positive for traumatic stress. Predeployment traumatic stress, greater combat exposure and sustaining an mTBI while deployed, and the BDNF Met/Met genotype accounted for 22% of the variance of postdeployment PTSD scores (R 2 = 0.22, P < 0.001). However, predeployment traumatic stress, alone, accounted for 17% of the postdeployment PTSD scores. Conclusion: These findings suggest predeployment traumatic stress, genetic, and environmental factors have unique contributions to the development of combat‐related traumatic stress in military service members.

This study examined whether intracranial neuroimaging abnormalities in those with mild traumatic brain injury (MTBI) (i.e., “complicated” MTBIs) are associated with worse subacute outcomes as measured by cognitive testing, symptom ratings, and/or diffusion tensor imaging (DTI). We hypothesized that (i) as a group, participants with complicated MTBIs would report greater symptoms and have worse neurocognitive outcomes than those with uncomplicated MTBI, and (ii) as a group, participants with complicated MTBIs would show more Diffusion Tensor Imaging (DTI) abnormalities. Participants were 62 adults with MTBIs (31 complicated and 31 uncomplicated) who completed neurocognitive testing, symptom ratings, and DTI on a 3T MRI scanner approximately 6-8 weeks post injury. There were no statistically significant differences between groups on symptom ratings or on a broad range of neuropsychological tests. When comparing the groups using tract-based spatial statistics for DTI, no significant difference was found for axial diffusivity or mean diffusivity. However, several brain regions demonstrated increased radial diffusivity (purported to measure myelin integrity), and decreased fractional anisotropy in the complicated group compared with the uncomplicated group. Finally, when we extended the DTI analysis, using a multivariate atlas based approach, to 32 orthopedic trauma controls (TC), the findings did not reveal significantly more areas of abnormal DTI signal in the complicated vs. uncomplicated groups, although both MTBI groups had a greater number of areas with increased radial diffusivity compared with the trauma controls. This study illustrates that macrostructural neuroimaging changes following MTBI are associated with measurable changes in DTI signal. Of note, however, the division of MTBI into complicated and uncomplicated subtypes did not predict worse clinical outcome at 6-8 weeks post injury.

Background: Many professional sports have introduced sideline video review to help recognise concussions. The reliability and validity of identifying clinical and observable signs of concussion using video analysis has not been extensively explored. This study examined the reliability and validity of clinical signs of concussion using video analysis in the National Rugby League (NRL). Methods: All 201 professional NRL matches from the 2014 season were reviewed to document six signs of possible concussion (unresponsiveness, slow to get up, clutching/shaking head, gait ataxia, vacant stare, and seizure). Results: A total of 127,062 tackles were reviewed. Getting up slowly was the most common observable sign (2240 times in the season, 1.8% of all tackles) but only 223 times where it appeared to be a possible concussion (0.2% of all tackles and 10.0% of the times it occurred). Additionally, clutching/shaking the head occurred 361 times (on 212 occasions this sign appeared to be due to a possible concussion), gait ataxia was observed 102 times, a vacant stare was noted 98 times, unresponsiveness 52 times, and a possible seizure 4 times. On 383 occasions, one or more of the observable signs were identified and deemed associated with a possible concussion. There were 175 incidences in which a player appeared to demonstrate two or more concussion signs, and 54 incidences where a player appeared to demonstrate three or more concussion signs. A total of 60 diagnosed concussions occurred, and the concussion interchange rule was activated 167 times. Intra-rater reliability (κ = 0.65–1.00) was moderate to perfect for all six video signs; however, the inter-rater reliability was not as strong (κ = 0.22–0.76). Most of the signs had relatively low sensitivity (0.18–0.75), but high specificity (0.85–1.00). Conclusions: Using video replay, observable signs of concussion appear to be sensitive to concussion diagnoses when reviewing known injuries among professional rugby league players. When reviewing an entire season, however, certain signs occur very commonly and did not identify concussion. Thus, the implementation of video review in the NRL is challenging, but can provide a useful addition to sideline concussion identification and removal from play decisions.

Background: There is a high comorbidity of posttraumatic stress (PTS) and mild traumatic brain injury (mTBI), with largely overlapping symptomatology, in military service members. Objective: To examine white matter integrity associated with PTS and mTBI as assessed using diffusion tensor imaging (DTI). Method: Seventy-four active-duty U.S. soldiers with PTS (n = 16) and PTS with co-morbid history of mTBI (PTS/mTBI; n = 28) were compared to a military control group (n = 30). Participants received a battery of neurocognitive and clinical symptom measures. The number of abnormal DTI values was determined (>2 SDs from the mean of the control group) for fractional anisotropy (FA) and mean diffusivity (MD), and then compared between groups. In addition, mean DTI values from white matter tracts falling into three categories were compared between groups: (i) projection tracts: superior, middle, and inferior cerebellar peduncles, pontine crossing tract, and corticospinal tract; (ii) association tracts: superior longitudinal fasciculus; and (iii) commissure tracts: cingulum bundle (cingulum-cingulate gyrus and cingulum-hippocampus), and corpus callosum. Results: The comorbid PTS/mTBI group had significantly greater traumatic stress, depression, anxiety, and post-concussive symptoms, and they performed worse on neurocognitive testing than those with PTS alone and controls. The groups differed greatly on several clinical variables, but contrary to what we hypothesized, they did not differ greatly on primary and exploratory analytic approaches of hetero-spatial whole brain DTI analyses. Conclusion: The findings suggest that psychological health conditions rather than pathoanatomical changes may be contributing to symptom presentation in this population.

Background: Video review has been introduced in many professional sports worldwide to help recognize concussions. However, to date, there has been very little research on the accuracy of using video analysis to identify signs of concussion and the various combinations of observed signs. Methods: The objective of the study is to determine the accuracy of combinations of clinical signs of concussion identified using video analysis to identify concussions in the National Rugby League (NRL). Incidences of players using of the concussion interchange rule (CIR) (n = 156), including those where athletes were diagnosed with a concussion (n = 60), were used to calculate sensitivity and specificity of various combinations of concussion signs (unresponsiveness, slow to get up, clutching/shaking head, gait ataxia, vacant stare, and apparent seizure) and their independent association with an eventual diagnosis of concussion. Results: Using video analysis, players who were diagnosed with a concussion showed a significantly greater total number of signs at the time of injury (mean = 3.4, SD = 1.3) than those who were removed from play but not diagnosed with a concussion (mean = 3.0, SD = 0.9 signs; p = .046). Players who did not return to play during the same game demonstrated a significantly greater number of total signs than those who did return to play in the same game following CIR activation (mean = 3.4, SD = 1.2 versus mean = 2.9, SD = 0.9; p = 0.002). The most common combination of signs that was observed was clutching/shaking the head and slowness in getting up (17.3%). The sensitivity of the total number of signs observed decreased as the number of signs increased (range = 0.13–0.62), while the specificity increased as more signs were observed (range = 0.29–0.90). Most of the combinations of different observed signs at the time of potential injury were highly specific (> 0.80), but not sensitive to an eventual diagnosis of concussion. When considering all potential predictor variables in a logistic regression model, anticipating the oncoming collision (OR = 3.92, 95% CI = 1.28–12.03), fewer number of defenders involved in the tackle (OR = 0.58, 95% CI = 0.36–0.92), and the presence of a blank or vacant stare (OR = 2.97, 95% CI = 1.26–7.01) were each significantly associated with concussion diagnoses. Conclusions: The use of video review in the NRL is challenging, but being aware of the combinations of possible concussion signs and the likelihood that various presentations result in a concussion diagnosis can provide a useful addition to sideline concussion identification and removal from play decisions.

Individuals who are injured in the workplace typically have a greater risk of delayed return to work (RTW) and other poor health outcomes compared to those not injured at work. It is not known whether these differences hold true for mild traumatic brain injuries (MTBI). The present study examined differences associated with workplace and non-workplace MTBI upon intake to a specialty MTBI clinic, their outcomes, and risk factors that influence RTW. Slow-to-recover participants were recruited from consecutive referrals to four outpatient MTBI clinics from March 2015 to February 2017. Two clinics treat Worker’s Compensation claimants and two clinics serve patients with non-work related injuries in the publically funded health care system. Of 273 eligible patients, 102 completed an initial study assessment (M age = 41.2 years, SD age = 11.7; 54% women) at an average of 2–3 months post injury. Participants were interviewed about their MTBI and completed a battery of standardized questionnaires and performance validity testing. Outcomes, including RTW, were assessed via telephone follow-up 4–5 months later. Workplace injuries comprised 45.1% of the sample. The workplace MTBI group had a greater proportion of men and lower education levels compared to the non-workplace MTBI group. The two groups had a comparable post-concussion symptom burden and performance validity test failure rate. Workplace MTBI was associated with greater post-traumatic stress symptoms. Fifteen patients (14.7%) were lost to follow-up. There were no workplace/non-workplace MTBI differences in RTW outcome at 6–7 months post injury. Of the entire sample, 42.5% of patients had full RTW, 18.4% had partial RTW, and 39.1% had no RTW. Greater post-concussion symptom burden was most predictive of no RTW at follow-up. There was no evidence that the workplace and non-workplace MTBI groups had different risk factors associated with prolonged work absence. Despite systemic differences in compensation and health care access, the workplace and non-workplace MTBI groups were similar at clinic intake and indistinguishable at follow-up, 6–7 months post injury.

Purpose The purpose of this study was to examine cortical thickness and subcortical volumes in professional rugby players with an extensive history of concussions compared to control subjects. Method Participants included 24 active and former professional rugby league players [Age M(SD) = 33.3(6.3); Range = 21–44] with an extensive history of concussion and 18 age- and education-matched controls with no history of neurotrauma or participation in contact sports. Participants underwent T1-weighted imaging and completed a neuropsychological battery, including two tests of memory. Whole brain cortical thickness analysis and structural volume analysis was performed using FreeSurfer version 6.0. Results: Professional rugby league players reported greater alcohol consumption (p < .001) and had significantly worse delayed recall of a visually complex design (p = .04). They did not differ from controls on other clinical outcome measures. There were no differences in cortical thickness between the groups. Professional players had smaller whole brain (p = .003), bilateral hippocampi (ps = .03), and left amygdala volumes (p = .01) compared to healthy controls. Within the players group, there were significant associations between greater alcohol use and smaller bilateral hippocampi and left amygdala volumes. There were no associations between structural volumes and history of concussions or memory performance. Conclusions: The literature examining cortical thickness in athletes with a history of multiple concussions is mixed. We did not observe differences in cortical thickness in professional rugby league players compared to controls. However, smaller subcortical volumes were found in players that were, in part, associated with greater alcohol consumption.