Grant L. Iverson

Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012

This paper is a revision and update of the recommendations developed following the 1st (Vienna 2001), 2nd (Prague 2004) and 3rd (Zurich 2008) International Consensus Conferences on Concussion in Sport and is based on the deliberations at the 4th International Conference on Concussion in Sport held in Zurich, November 2012.1–3 The new 2012 Zurich Consensus statement is designed to build on the principles outlined in the previous documents and to develop further conceptual understanding of this problem using a formal consensus-based approach. A detailed description of the consensus process is outlined at the end of this document under the Background section. This document is developed primarily for use by physicians and healthcare professionals who are involved in the care of injured athletes, whether at the recreational, elite or professional level. While agreement exists pertaining to principal messages conveyed within this document, the authors acknowledge that the science of concussion is evolving, and therefore management and return to play (RTP) decisions remain in the realm of clinical judgement on an individualised basis. Readers are encouraged to copy and distribute freely the Zurich Consensus document, the Concussion Recognition Tool (CRT), the Sports Concussion Assessment Tool V.3 (SCAT3) and/or the Child SCAT3 card and none are subject to any restrictions, provided they are not altered in any way or converted to a digital format. The authors request that the document and/or the accompanying tools be distributed in their full and complete format. This consensus paper is broken into a number of sections 1. A summary of concussion and its management, with updates from the previous meetings; 2. Background information about the consensus meeting process; 3. A summary of the specific consensus questions discussed at this meeting; 4. The Consensus paper should be read in conjunction with the SCAT3 assessment tool, the Child SCAT3 and the CRT …

The American College of Rheumatology nomenclature and case definitions for neuropsychiatric lupus syndromes

OBJECTIVE To develop a standardized nomenclature system for the neuropsychiatric syndromes of systemic lupus erythematosus (NPSLE). METHODS An international, multidisciplinary committee representing rheumatology, neurology, psychiatry, neuropsychology, and hematology developed case definitions, reporting standards, and diagnostic testing recommendations. Before and after the meeting, clinician committee members assigned diagnoses to sets of vignettes randomly generated from a pool of 108 NPSLE patients. To assess whether the nomenclature system improved diagnostic agreement, a consensus index was developed and pre- and postmeeting scores were compared by t-tests. RESULTS Case definitions including diagnostic criteria, important exclusions, and methods of ascertainment were developed for 19 NPSLE syndromes. Recommendations for standard reporting requirements, minimum laboratory evaluation, and imaging techniques were formulated. A short neuropsychological test battery for the diagnosis of cognitive deficits was proposed. In the postmeeting exercise, a statistically significant improvement in diagnostic agreement was observed. CONCLUSION The American College of Rheumatology (ACR) Nomenclature for NPSLE provides case definitions for 19 neuropsychiatric syndromes seen in SLE, with reporting standards and recommendations for laboratory and imaging tests. It is intended to facilitate and enhance clinical research, particularly multicenter studies, and reporting. In clinical settings, consultation with other specialists may be required. It should be useful for didactic purposes but should not be used uncritically or as a substitute for a clinical diagnosis. The complete case definitions are available on the ACR World Wide Web site: http://www.rheumatology .org/ar/ar.html.

Diagnostic Criteria for Malingered Neurocognitive Dysfunction: Proposed Standards for Clinical Practice and Research

Over the past 10 years, widespread and concerted research efforts have led to increasingly sophisticated and efficient methods and instruments for detecting exaggeration or fabrication of cognitive dysfunction. Despite these psychometric advances, the process of diagnosing malingering remains difficult and largely idiosyncratic. This article presents a proposed set of diagnostic criteria that define psychometric, behavioral, and collateral data indicative of possible, probable, and definite malingering of cognitive dysfunction, for use in clinical practice and for defining populations for clinical research. Relevant literature is reviewed, and limitations and benefits of the proposed criteria are discussed.

Outcome from mild traumatic brain injury

Purpose of review The focus of this review is outcome from mild traumatic brain injury. Recent literature relating to pathophysiology, neuropsychological outcome, and the persistent postconcussion syndrome will be integrated into the existing literature. Recent findings The MTBI literature is enormous, complex, methodologically flawed, and controversial. There have been dozens of studies relating to pathophysiology, neuropsychological outcome, and the postconcussion syndrome during the past year. Two major reviews have been published. Some of the most interesting prospective research has been done with athletes. Summary The cognitive and neurobehavioral sequelae are self-limiting and reasonably predictable. Mild traumatic brain injuries are characterized by immediate physiological changes conceptualized as a multilayered neurometabolic cascade in which affected cells typically recover, although under certain circumstances a small number might degenerate and die. The primary pathophysiologies include ionic shifts, abnormal energy metabolism, diminished cerebral blood flow, and impaired neurotransmission. During the first week after injury the brain undergoes a dynamic restorative process. Athletes typically return to pre-injury functioning (assessed using symptom ratings or brief neuropsychological measures) within 2–14 days. Trauma patients usually take longer to return to their pre-injury functioning. In these patients recovery can be incomplete and can be complicated by preexisting psychiatric or substance abuse problems, poor general health, concurrent orthopedic injuries, or comorbid problems (e.g. chronic pain, depression, substance abuse, life stress, unemployment, and protracted litigation).

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.

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.