Michael W. Collins

Recovery from mild concussion in high school athletes

OBJECT A computerized neuropsychological test battery was conducted to evaluate memory dysfunction and self-reporting of symptoms in a group of high school athletes who had suffered concussion. METHODS Neuropsychological performance prior to and following concussion was compared with the test performance of an age-matched control group. Potentially important diagnostic markers of concussion severity are discussed and linked to recovery within the 1st week of injury. CONCLUSIONS High school athletes who had suffered mild concussion demonstrated significant declines in memory processes relative to a noninjured control group. Statistically significant differences between preseason and postinjury memory test results were still evident in the concussion group at 4 and 7 days postinjury. Self-reported neurological symptoms such as headache, dizziness, and nausea resolved by Day 4. Duration of on-field mental status changes such as retrograde amnesia and posttraumatic confusion was related to the presence of memory impairment at 36 hours and 4 and 7 days postinjury and was also related to slower resolution of self-reported symptoms. The results of this study suggest that caution should be exercised in returning high school athletes to the playing field following concussion. On-field mental status changes appear to have prognostic utility and should be taken into account when making return-to-play decisions following concussion. Athletes who exhibit on-field mental status changes for more than 5 minutes have longer-lasting postconcussion symptoms and memory decline.

Cumulative effects of concussion in high school athletes.

OBJECTIVE A common assumption in sports medicine is that a history of concussion is predictive of a lower threshold for, as well as a worse outcome after, subsequent concussive injury. The current study was conducted to investigate the relationship between concussion history in high school athletes and the on-field presentation of symptoms after subsequent concussion. METHODS One hundred seventy-three athletes who experienced sports-related concussion composed the initial study group. Binary groups were subsequently created on the basis of concussion history. Sixty athletes with no concussion history were compared with 28 athletes with a history of three or more concussions. The groups were compared in terms of the on-field presentation of symptoms after an in-study concussion. Dependent variables included the postinjury presence of loss of consciousness, anterograde amnesia, retrograde amnesia, and confusion. RESULTS Athletes with three or more prior concussions were more likely to experience on-field positive loss of consciousness (&khgr;2 = 8.0, P = 0.005), anterograde amnesia (&khgr;2 = 5.5, P = 0.019), and confusion (&khgr;2 = 5.1, P = 0.024) after a subsequent cerebral concussion. An odds ratio revealed that athletes with a history of three concussions were 9.3 times more likely than athletes with no history of concussion to demonstrate three to four abnormal on-field markers of concussion severity. CONCLUSION This study is the first to suggest a cumulative effect of concussion in high school athletes. A more severe on-field presentation of concussion markers is evidenced in high school athletes with a pronounced history of concussion. This study’s findings highlight the need for more long-term outcome studies in high school athletes who sustain sports-related concussions.

Cumulative effects of concussion in amateur athletes

Primary objective: To examine the possibility that athletes with multiple concussions show cumulative effects of injury. Methods and procedures: Amateur athletes with a history of three or more concussions were carefully matched (gender, age, education and sport) with athletes with no prior concussions. All completed a computerized neuropsychological test battery at preseason (ImPACT) and then within 5 days of sustaining a concussion (mean = 1.7 days). Main outcomes and results: There were differences between groups in symptom reporting and memory performance. At baseline (i.e. preseason), athletes with multiple concussions reported more symptoms than athletes with no history of concussion. At approximately 2 days post-injury, athletes with multiple concussions scored significantly lower on memory testing than athletes with a single concussion. Athletes with multiple concussions were 7.7 times more likely to demonstrate a major drop in memory performance than athletes with no previous concussions. Conclusions: This study provides preliminary evidence to suggest that athletes with multiple concussions might have cumulative effects.

Neuropsychological assessment of the college football player

The application of neuropsychological assessment procedures to the evaluation of athletes has recently become an area of intense interest and debate and has led to the development of research initiatives at both the amateur and the professional level. However, to date, only a handful of research studies have been completed that have addressed the special issues that accompany the use of neuropsychological assessment instruments with athletes. This article reviews the past use of psychological testing in sports and presents a model of neuropsychological assessment that is currently being utilized in the National Football League. In addition, the extension of this approach to major college football is discussed and test-retest data from a sample presented to provide the basis for comparison of athletes who have suffered a concussion. Recommendations of a national panel of neuropsychologlsts who are involved in the evaluation of athletes are presented in hopes of encouraging new research initiatives in this area.

Measurement of Symptoms Following Sports-Related Concussion: Reliability and Normative Data for the Post-Concussion Scale

It is important to carefully evaluate self-reported symptoms in athletes with known or suspected concussions. This article presents data on the psychometric and clinical properties of a commonly used concussion symptom inventory-the Post-Concussion Scale. Normative and psychometric data are presented for large samples of young men (N = 1,391) and young women (N = 355). In addition, data gathered from a concussed sample of athletes (N = 260) seen within 5 days of injury are presented. These groups represent samples of both high school and collegiate athletes. Data from a subsample of 52 concussed athletes seen 3 times post-injury are presented to illustrate symptom reporting patterns during the initial recovery period. General guidelines for the clinical use of the scale are provided.

Interpreting Change on ImPACT Following Sport Concussion

The purpose of this study was to examine the psychometric characteristics of Version 2.0 of ImPACT (Immediate Postconcussion Assessment and Cognitive Testing). The focus was on the stability of the test scores and the calculation of reliable change confidence intervals for the test-retest difference scores. A sample of 56 nonconcussed adolescents and young adults completed the test battery on two occasions. Test-retest coefficients, reliable change difference scores, and confidence intervals for measurement error are provided. These reliable change parameters were applied to a second sample of 41 concussed amateur athletes who were tested preseason and within 72 hr of injury. Applying these confidence intervals allows more precise determinations of deterioration, improvement, and recovery in the initial days following concussion.

On-field predictors of neuropsychological and symptom deficit following sports-related concussion.

ObjectiveInvestigate the relationship between on-field markers of concussion severity and postinjury neuropsychological and symptom presentation in an athlete-specific population. DesignCase control study. SettingMulticenter analysis of high school and college athletes. ParticipantsA total of 78 athletes sustaining sports-related concussion were selected from a larger sample of 139 concussed athletes. Assessment of Predictor VariablesOn-field presence of disorientation, posttraumatic amnesia, retrograde amnesia, and loss of consciousness. Main Outcome MeasuresImPACT, a computerized neuropsychological test battery, was administered pre-season and, on average, 2 days postinjury. Good postinjury presentation (n = 44) was defined as no measurable change, relative to baseline, in terms of both ImPACT memory and symptom composite scores. Poor presentation (n = 34) was defined as a 10-point increase in symptom reporting and 10-point decrease in memory functioning (exceeding the 80% confidence interval for measurement error on ImPACT). Athletes failing to meet good or poor selection criteria (n = 61) were not included in the analysis. ResultsOdds ratios revealed that athletes demonstrating poor presentation at 2 days postinjury were over 10 times more likely (P < 0.001) to have exhibited retrograde amnesia following concussive injury when compared with athletes exhibiting good presentation. Similarly, athletes with poor presentation were over 4 times more likely (P < 0.013) to have exhibited posttraumatic amnesia and at least 5 minutes of mental status change. There were no differences between good and poor presentation groups in terms of on-field loss of consciousness. ConclusionsThe presence of amnesia, not loss of consciousness, appears predictive of symptom and neurocognitive deficits following concussion in athletes. Athletes presenting with on-field amnesia should undergo comprehensive and individualized assessment prior to returning to sport participation. Continued refinement of sports concussion grading scales is warranted in lieu of consistent findings that brief loss of consciousness is not predictive of concussion injury severity.

Grade 1 or “Ding” Concussions in High School Athletes:

Background Recent concussion management guidelines have suggested that athletes with mild (grade 1) concussions may be returned to play if asymptomatic for 15 minutes. The purpose of this study was to assess the utility of a current concussion management guideline in classifying and managing mild concussion. Hypothesis High school athletes diagnosed with a grade 1 concussion will demonstrate measurable decline in neuropsychological functioning that persists during the 1st week of recovery. Study Design Prospective study designed to evaluate neuropsychological functioning both prior to and following concussion. Methods Forty-three high school athletes completed neuropsychological test performance and symptom ratings prior to the season and at two times during the 1st week following mild concussion. Results Thirty-six hours after injury, mildly concussed high school athletes demonstrated a decline in memory (P < 0.003) and a dramatic increase in self-reported symptoms (P < 0.00001) compared to baseline performance. Conclusions Athletes with grade 1 concussion demonstrated memory deficits and symptoms that persisted beyond the context in which they were injured. These data suggest that current grade 1 return-to-play recommendations that allow for immediate return to play may be too liberal. Clinical Relevance A reconsideration of current concussion grading systems appears to be warranted.

Tracking neuropsychological recovery following concussion in sport

Primary objective: The purpose of this study was to illustrate the serial use of computerized neuropsychological screening with ImPACT to monitor recovery in a clinical case series of injured athletes. Methods and procedures: Amateur athletes with concussions (n = 30, average age = 16.1, SD = 2.1 years) underwent pre-season testing and three post-concussion evaluations within the following intervals: 1–2 days, 3–7 days (M = 5.2 days) and 1–3 weeks (M = 10.3 days). The study selection criteria increased the probability of including athletes with slow recovery. Results: Repeated measures ANOVAs revealed significant main effects for all five composite scores (verbal memory, visual memory, reaction time, processing speed and total symptoms). In group analyses, performance decrements and symptoms relating to concussion appeared to largely resolve by 5 days post-injury and fully resolve by 10 days. Athletes’ scores were examined individually using the reliable change methodology. At 1 day post-injury, 90% had two or more reliable declines in performance or increases in symptom reporting. At 10 days, 37% were still showing two or more reliable changes from pre-season levels. Conclusions: This study illustrates the importance of analysing individual athletes’ test data because group analyses can obscure slow recovery in a substantial minority of athletes.

Concussion in Sports: Postconcussive Activity Levels, Symptoms, and Neurocognitive Performance

CONTEXT Evidence suggests that athletes engaging in high-intensity activities after concussion have more difficulties with cognitive recovery. OBJECTIVE To examine the role postinjury activity level plays in postconcussive symptoms and performance on neurocognitive tests in a population of student-athletes. DESIGN Retrospective cohort study with repeated measures of neurocognitive performance and symptom reporting. SETTING University-based sports concussion clinic. PATIENTS OR OTHER PARTICIPANTS Ninety-five student-athletes (80 males, 15 females: age = 15.88 +/- 1.35 years) were retrospectively assigned to 1 of 5 groups based on a postinjury activity intensity scale. MAIN OUTCOME MEASURE(S) We employed a regression analysis for repeated measures to evaluate the relationship of activity intensity to symptoms and neurocognitive outcome up to 33 days after concussion. Postconcussion symptom scores and neurocognitive (verbal memory, visual memory, visual motor speed, and reaction time) scores served as the primary outcome measures. RESULTS Level of exertion was significantly related to all outcome variables (P < .02 for all comparisons). With multivariate analysis, activity intensity remained significant with respect to visual memory (P = .003) and reaction time (P < .001). CONCLUSIONS Activity level after concussion affected symptoms and neurocognitive recovery. Athletes engaging in high levels of activity after concussion demonstrated worse neurocognitive performance. For these tasks, those engaging in moderate levels of activity demonstrated the best performance.