Michael S. Ferrara

National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses.

OBJECTIVE To present best-practice recommendations for the prevention, recognition, and treatment of exertional heat illnesses (EHIs) and to describe the relevant physiology of thermoregulation. BACKGROUND Certified athletic trainers recognize and treat athletes with EHIs, often in high-risk environments. Although the proper recognition and successful treatment strategies are well documented, EHIs continue to plague athletes, and exertional heat stroke remains one of the leading causes of sudden death during sport. The recommendations presented in this document provide athletic trainers and allied health providers with an integrated scientific and clinically applicable approach to the prevention, recognition, treatment of, and return-to-activity guidelines for EHIs. These recommendations are given so that proper recognition and treatment can be accomplished in order to maximize the safety and performance of athletes. RECOMMENDATIONS Athletic trainers and other allied health care professionals should use these recommendations to establish onsite emergency action plans for their venues and athletes. The primary goal of athlete safety is addressed through the appropriate prevention strategies, proper recognition tactics, and effective treatment plans for EHIs. Athletic trainers and other allied health care professionals must be properly educated and prepared to respond in an expedient manner to alleviate symptoms and minimize the morbidity and mortality associated with these illnesses.

Sensitivity of the concussion assessment battery.

OBJECTIVESports medicine clinicians commonly use multiple tests when evaluating patients with concussion. The specific tests vary but often include symptom inventories, posturography, and neurocognitive examinations. The sensitivity of these tests to concussion is vital in reducing the risk for additional injury by prematurely returning an athlete to play. Our study investigated the sensitivity of concussion-related symptoms, a postural control evaluation, and neurocognitive functioning in concussed collegiate athletes. METHODSFrom 1998 to 2005, all high-risk athletes completed a baseline concussion-assessment battery that consisted of a self-reported symptom inventory, a postural control evaluation, and a neurocognitive assessment. Postconcussion assessments were administered within 24 hours of injury to 75 athletes who had physician-diagnosed concussion. Individual tests and the complete battery were evaluated for sensitivity to concussion. RESULTSThe computerized Immediate Post-Concussion Assessment and Cognitive Testing and HeadMinder Concussion Resolution Index (neurocognitive tests) were the most sensitive to concussion (79.2 and 78.6%, respectively). These tests were followed by self-reported symptoms (68.0%), the postural control evaluation (61.9%), and a brief pencil-and-paper assessment of neurocognitive function (43.5%). When the complete battery was assessed, sensitivity exceeded 90%. CONCLUSIONCurrently recommended concussion-assessment batteries accurately identified decrements in one or more areas in most of the athletes with concussion. These findings support previous recommendations that sports-related concussion should be approached through a multifaceted assessment with components focusing on distinct aspects of the athletes function.

Evaluation of neuropsychological domain scores and postural stability following cerebral concussion in sports

ContextWith increasing knowledge and research about concussion, there have been few objective studies that have used neuropsychological domain scores and postural stability to assess concussion. ObjectiveTo evaluate the recovery curve of athletes who incur sport-related concussion from repeated serial testing of neuropsychological and posturography testing. DesignA prospective epidemiological model was used for the course of the study. SettingDivision I intercollegiate athletics. ParticipantsAthletes participating in football, soccer, basketball, softball, and cheerleading. Main Outcome MeasuresNeuropsychological scores and posturography measures were obtained preseason and serially at day 1, day 2, day 3, and day 10 postconcussion. Control participants were tested at the same intervals. Neuropsychological scores were converted to standards score and then into domains of attention, learning, speed of information processing, concentration, memory, and verbal fluency. Analysis of covariance with the baseline test as the covariate was used to analyze the data with univariate post hoc tests performed. ResultsSignificant group differences were found for self reported symptoms (P = 0.001), speed of information processing (P = 0.005), mean stability (P = 0.002), and vestibular function (P = 0.003) between injured and control participants. A group, by day, planned comparison found that speed of information processing and composite balance measures demonstrated significant differences through day 10 postinjury, while symptoms and the vestibular ratio remained significant only through day 3. ConclusionsThe concussion recovery curve demonstrated short-term neuropsychological and posturography deficits following injury. A comprehensive approach to concussion management should be used to assess the injury and make return-to-play decisions.

Concussion history is not a predictor of computerised neurocognitive performance

Background: The long term effects of self reported concussion on neurocognitive functioning have been found to be variable. Objectives: To evaluate cognitive performance on the Headminder concussion resolution index (CRI) and ImPACT assessment tests of subjects with and without a history of self reported concussion. Methods: A retrospective analysis was completed on 235 Headminder CRI baseline assessments and 264 ImPACT baseline assessments. Participants were divided into four groups on the basis of reported number of concussions (zero, one, two, or three). Multivariate analysis of variance was used to evaluate differences between the concussion history groups on the two computer based concussion assessment programs. Results: Multivariate analysis of variance indicated no significant difference between those with and without a history of concussion on the CRI (Λ  =  0.963, F(15, 627.05)  =  0.57, p  =  0.898). It also revealed no significant differences between groups on the ImPACT test (Λ  =  0.951, F(12, 672.31)  =  1.07, p  =  0.381). Conclusions: The results suggest that either long term cognitive decrements may not be associated with a history of concussion or the decrements may be subtle and undetectable by these computer programs.

Injuries to athletes with disabilities: identifying injury patterns.

Participation in sport activities for people with disabilities continues to gain in popularity. With participation in sports, there is an inherent risk of injury. A review of current sport epidemiological studies was used and we concluded that injury patterns for this population are similar to those for athletes without disabilities. Injury data from Paralympic competitions dating back to 1976 indicate that most elite athletes with disabilities seek medical care for illness and musculoskeletal injuries. However, there are very limited injury data regarding Winter Paralympic events or skiing injuries. For those athletes who participate in Summer Paralympic events, abrasions, strains, sprains and contusions are more common than fractures and dislocations. However, location of injuries appears to be disability and sport dependent. Lower extremity injuries are more common in ambulatory athletes (visually impaired, amputee, cerebral palsy) and upper extremity injuries are more frequent in athletes who use a wheelchair. While it appears that the majority of the injuries occurring in this population are minor in nature, inconsistencies in the definition of injury in the literature make this conclusion tenuous. When injuries are expressed as time lost in participation, 52% of injuries resulted in 7 days lost or less, 29% in 8 to 21 days lost and 19% in greater than 22 days lost. The only prospective study addressing injury rates of athletes with disabilities in a manner consistent with other sport epidemiological studies found an injury rate of 9.3 injuries per 1000 athlete-exposures (AE). This injury rate is less than American football (10.1 to 15/1000 AE) and soccer (9.8/1000 AE), and greater than basketball (7.0/1000 AE). It is unclear whether comparative statistics such as these take into consideration the number of illness and injury episodes that resulted from the disability. Further complicating epidemiological studies for athletes with disabilities is the definition of the population and samples of convenience which are frequently used. These samples are often not representative of the multiplicity of disability conditions, levels of competition and range of sport activities available. Prospective studies comparing athletes to sedentary control individuals to measure differences in injury rates, type and frequency between and within disability groups, sports and levels of competition are desperately needed to further the knowledge of injury trends and develop and establish accurate injury prevention programmes.

ImPact Test-Retest Reliability: Reliably Unreliable?

CONTEXT Computerized neuropsychological testing is commonly used in the assessment and management of sport-related concussion. Even though computerized testing is widespread, psychometric evidence for test-retest reliability is somewhat limited. Additional evidence for test-retest reliability is needed to optimize clinical decision making after concussion. OBJECTIVE To document test-retest reliability for a commercially available computerized neuropsychological test battery (ImPACT) using 2 different clinically relevant time intervals. DESIGN Cross-sectional study. SETTING Two research laboratories. PATIENTS OR OTHER PARTICIPANTS Group 1 (n = 46) consisted of 25 men and 21 women (age = 22.4 ± 1.89 years). Group 2 (n = 45) consisted of 17 men and 28 women (age = 20.9 ± 1.72 years). INTERVENTION(S) Both groups completed ImPACT forms 1, 2, and 3, which were delivered sequentially either at 1-week intervals (group 1) or at baseline, day 45, and day 50 (group 2). Group 2 also completed the Green Word Memory Test (WMT) as a measure of effort. MAIN OUTCOME MEASURES Intraclass correlation coefficients (ICCs) were calculated for the composite scores of ImPACT between time points. Repeated-measures analysis of variance was used to evaluate changes in ImPACT and WMT results over time. RESULTS The ICC values for group 1 ranged from 0.26 to 0.88 for the 4 ImPACT composite scores. The ICC values for group 2 ranged from 0.37 to 0.76. In group 1, ImPACT classified 37.0% and 46.0% of healthy participants as impaired at time points 2 and 3, respectively. In group 2, ImPACT classified 22.2% and 28.9% of healthy participants as impaired at time points 2 and 3, respectively. CONCLUSIONS We found variable test-retest reliability for ImPACT metrics. Visual motor speed and reaction time demonstrated greater reliability than verbal and visual memory. Our current data support a multifaceted approach to concussion assessment using clinical examinations, symptom reports, cognitive testing, and balance assessment.

Previous mild traumatic brain injury and postural-control dynamics

CONTEXT Postural control and cognitive function are adversely affected by acute mild traumatic brain injury (mTBI). Whether postural-control deficits persist beyond the acute stage in individuals with a history of mTBI is unclear. OBJECTIVE To determine if postural-control deficits persist in individuals with a history of mTBI. DESIGN Retrospective cross-sectional study. SETTING University research laboratory. PATIENTS OR OTHER PARTICIPANTS As part of an ongoing investigation examining cognitive and motor deficits associated with mTBI, 224 individuals participated in the study. Of these, 62 participants self-reported at least 1 previous physician-diagnosed mTBI. INTERVENTION(S) Postural control was assessed using the NeuroCom Sensory Organization Test (SOT) postural-assessment battery. MAIN OUTCOME MEASURE(S) The SOT postural assessment yields 4 indices of postural control: a composite balance score, a visual ratio score, a somatosensory score, and a vestibular score. Postural dynamics were also examined by calculating approximate entropy of center-of-pressure excursions in the anteroposterior and mediolateral axis for each test condition. RESULTS Minimal differences in the SOT indices were noted among individuals with and without a history of previous mTBI (P > .05). In the group with a history of mTBI, anteroposterior postural irregularity decreased as postural difficulty increased. In contrast, the group without a history of mTBI displayed increased postural irregularity in the mediolateral direction. CONCLUSIONS Individuals with a history of mTBI exhibited altered postural dynamics compared with individuals without a history of mTBI. These findings support the notion that changes in cerebral functioning that affect postural control may persist long after acute injury resolution.

The relationship of athlete-reported concussion symptoms and objective measures of neurocognitive function and postural control.

Objective:Concussed athlete evaluations often include symptoms, balance, and neurocognitive assessments. We sought to identify the relationship between subjective symptom reports and objective clinical measures. Design:A retrospective assessment. Setting:A research laboratory. Patients:Concussed collegiate-level athletes (N = 32, 19.7 years) evaluated pre- and postinjury (less than 48 hours). Intervention:Each athlete completed an inventory of concussion-related symptoms, the NeuroCom Sensory Organization Test (SOT), and ImPACT neurocognitive assessment. Spearman correlations between balance symptoms and SOT scores and cognitive symptoms and ImPACT scores were completed. Main Outcome Measures:Symptoms related to balance and cognitive deficits, SOT composite balance and visual, vestibular, and somatosensory ratios, and ImPACT output scores. Results:Significant Spearman correlations were noted between reports of “dizziness” and the SOT composite balance (rs = -0.55) and vestibular ratio (rs = -0.50). Similarly, “balance problems” were significantly correlated with composite balance (rs = -0.52) and the somatosensory (rs = -0.41), visual (rs = -0.39), and vestibular ratios (rs = -0.57). The cognitive symptom of “feeling mentally foggy” and ImPACT variables of reaction time (rs = 0.36) and “difficulty concentrating” and verbal memory score (rs = -0.41) were significantly related. Finally, reports of “difficultly remembering” were significantly related to the verbal memory score (rs = -0.48) and reaction time (rs = 0.36). Conclusions:These findings indicate self-report symptoms are associated with athlete deficits in postural control and cognitive function. The moderate relationship between the symptom reports and the objective measures warrants the continued use of all measures. A reduction in the number of symptoms concussed athletes respond to may be justified to reduce redundancy.

Reliable change of the sensory organization test

Objective:To establish the sensitivity and specificity of the NeuroCom Sensory Organization Test (SOT) and provide practitioners with cut-scores for clinical decision making using estimates of reliable change. Design:Retrospective cohort study. Setting:Research laboratory. Patients:Healthy (n = 66) and concussed (n = 63) young adult participants. Interventions:Postural control assessments on the NeuroCom SOT were completed twice (baseline and follow-up) for both groups. Postconcussion assessments were administered within 24 hours of injury diagnosis. Main Outcome Measurements:The reliable change technique was used to calculated cut-scores for each SOT variable (composite balance; somatosensory, visual, and vestibular ratios) at the 95%, 90%, 85%, 80%, 75%, and 70% confidence interval levels. Results:When cut-scores were applied to the post-concussion evaluations, sensitivity and specificity varied with SOT variable and confidence interval. An evaluation for change on one or more SOT variable resulted in the highest combined sensitivity (57%) and specificity (80%) at the 75% confidence interval. Conclusions:Use of reliable change scores to detect significant changes in performance on the SOT resulted in decreased sensitivity and improved specificity compared to a previous report. These findings indicate that some concussed athletes may not show large changes in postconcussion postural control and this postural control evaluation should not be used in exclusion of other assessment techniques. The postural control assessment should be combined with other evaluative measures to gain the highest sensitivity to concussive injuries.

Balance performance with a cognitive task: a dual-task testing paradigm.

PURPOSE Athletic performance demands simultaneous use of cognitive and postural control capabilities. Decrements to both systems have been observed following concussion. This study evaluated a dual-task methodology to establish the tenability of using this testing model in concussed athletes. METHODS Nonconcussed subjects were assessed over 2 d. Subjects were introduced to the task-switching cognitive assessment test and a NeuroCom Smart Balance Master postural control assessment protocol on day 1. In the following session, subjects were evaluated on postural control and cognitive function tests independently (single task), and then concurrently (dual task). RESULTS Significant improvements were seen in three of the four balance conditions and in three of the four reaction times when the cognitive and balance task were performed simultaneously (P<0.05). No significant balance by cognitive task interaction was revealed (P>0.05); however, significant differences existed in reaction time based on stimulus position and increasing balance demands (P<0.05). CONCLUSION Combining the cognitive and balance assessments resulted in healthy subjects showing improved performance when compared with individual task performance. The dual-task methodology brought about systematic changes to reaction time in relation to increasing balance demands. The ability of this protocol to detect changes in postural control or cognitive function following concussive injury requires further study.