Amanda R. Rabinowitz

Cognitive Sequelae of Traumatic Brain Injury

Cognitive dysfunction is the leading cause of disability following traumatic brain injury (TBI). This article provides a review of the cognitive sequelae of TBI, with a focus on deficits of executive functioning and everyday thinking skills. The pathophysiology, assessment, and treatment of TBI-related cognitive problems are also discussed.

Predictors and prevalence of postconcussion depression symptoms in collegiate athletes.

CONTEXT Depression is common after concussion and is associated with functional outcome and quality of life after injury. However, few baseline predictors of postconcussion depressive symptoms (PCDS) have been found. OBJECTIVE To describe the prevalence of depressive symptoms in a collegiate athlete sample at baseline and postconcussion, compare these levels of symptoms and change in symptoms with those of a control group with no reported concussions in the past year, and examine the baseline predictors for PCDS. DESIGN Case-control study. SETTING Undergraduate institution. PATIENTS OR OTHER PARTICIPANTS Participants were 84 collegiate athletes (65 men, 19 women) with concussion and 42 individuals (23 men, 21 women) with no history of recent concussion who served as controls. MAIN OUTCOME MEASURE(S) The Beck Depression Inventory-Fast Screen was administered to the concussion group at baseline and postconcussion and to the control group at 2 time points. RESULTS Seventeen athletes (20%) showed a reliable increase in depression, and more athletes reported clinically important depression postconcussion than at baseline. Only 2 participants (5%) in the control group showed a reliable increase in depression. Concussed athletes were more likely to show a reliable increase in depression symptoms than control participants (χ(2)1 = 5.2, P = .02). We also found several predictors of PCDS in the athletes, including baseline depression symptoms (r = 0.37, P < .001), baseline postconcussion symptoms (r = 0.25, P = .03), estimated premorbid intelligence (full-scale IQ; r = -0.29, P = .009), and age of first participation in organized sport (r = 0.34, P = .002). For the control group, predictors of depression symptoms at time 2 were number of previous head injuries (r = 0.31, P = .05) and baseline depression symptoms (r = 0.80, P < .001). CONCLUSIONS A large proportion of athletes showed a reliable increase in depression after concussion, and we identified several baseline predictors. Given that depression affects quality of life and recovery from concussion, more research is necessary to better understand why certain athletes show an increase in PCDS and how these can be better predicted and prevented.

Prevalence and Predictors of Poor Recovery from Mild Traumatic Brain Injury

Although most patients with mild traumatic brain injury (mTBI) recover within 3 months, a subgroup of patients experience persistent symptoms. Yet, the prevalence and predictors of persistent dysfunction in patients with mTBI remain poorly understood. In a longitudinal study, we evaluated predictors of symptomatic and cognitive dysfunction in adolescents and young adults with mTBI, compared with two control groups-patients with orthopedic injuries and healthy uninjured individuals. Outcomes were assessed at 3 months post-injury. Poor symptomatic outcome was defined as exhibiting a symptom score higher than 90% of the orthopedic control (OC) group, and poor cognitive outcome was defined as exhibiting cognitive performance poorer than 90% of the OC group. At 3 months post-injury, more than half of the patients with mTBI (52%) exhibited persistently elevated symptoms, and more than a third (36.4%) exhibited poor cognitive outcome. The rate of high symptom report in mTBI was markedly greater than that of typically developing (13%) and OC (17%) groups; the proportion of those with poor cognitive performance in the mTBI group exceeded that of typically developing controls (15.8%), but was similar to that of the OC group (34.9%). Older age at injury, female sex, and acute symptom report were predictors of poor symptomatic outcome at 3 months. Socioeconomic status was the only significant predictor of poor cognitive outcome at 3 months.

Sport and Nonsport Etiologies of Mild Traumatic Brain Injury: Similarities and Differences

Mild traumatic brain injury (mTBI) has recently gained appreciation as a significant public health problem, which has highlighted just how little is known about its proximal and long-term effects. A major challenge in the study of mTBI is the heterogeneity of the condition. Research on mTBI has historically separated sport and nonsport etiologies, and the extent to which research from one of these samples translates to the other is unclear. This review examines the literature on mTBI, with a focus on comparing sport and nonsport etiologies with regard to the latest research on biomechanics, pathophysiology, neurocognitive effects, and neuroimaging. Issues of particular relevance to sports injuries, such as exercise, repetitive injuries, subconcussive blows, and chronic injury effects, are also reviewed.

Intraindividual Cognitive Variability Before and After Sports-Related Concussion

OBJECTIVE Inconsistent performance is associated with cognitive dysfunction in a number of clinical populations. However, intraindividual cognitive variability in healthy individuals is poorly understood. Inconsistency poses a challenge to clinicians when interpreting change over time. This study examined intraindividual cognitive variability within a sample of college athletes tested at baseline and postconcussion. METHOD Athletes (n = 71) and control participants (n = 42) were tested with a comprehensive neuropsychological battery at baseline and postconcussion (athletes) or one month later (controls). A subset of indices with high internal consistency was used to calculate overall performance and performance variability. A k-means cluster analysis of baseline and postconcussion performance variability examined heterogeneity within the sample. RESULTS In the athlete sample, performance variability was significantly greater than zero, and was negatively correlated with overall performance at both time points (p < .001). Wechsler Test of Adult Reading Full Scale IQ estimate was significantly correlated with overall performance (p < .01), but not with performance variability. Cluster analysis revealed low-variability (n = 46) and high-variability (n = 25) cluster groups. Whereas the low-variability cluster group exhibited a pattern of performance similar to that of control participants, membership in the high-variability cluster group was associated with postconcussion cognitive dysfunction. CONCLUSION These findings suggest that normative cognitive performance in college athletes is characterized by significant intraindividual variation across tests. Cross-test intraindividual variability may impart clinically meaningful information, as higher levels of variability were related to poorer overall performance and postconcussion cognitive dysfunction.

Injury-related predictors of symptom severity following sports-related concussion

Introduction: Decisions regarding return to play after sports-related concussion partially revolve around athletes’ self-reported symptoms. Given this emphasis on symptoms, it would be beneficial to be able to identify characteristics that could predict which athletes may be susceptible to developing an increase in postconcussion symptoms following head injury. The purpose of this study was to describe the symptoms that athletes endorse immediately following concussion and to determine what impact injury-related characteristics have on the development of postconcussion symptoms within the first week following concussion. Method: Participants included 54 collegiate athletes who sustained concussions and were referred to our concussion management program for postconcussion testing. The main outcome measures included the Post-Concussion Symptom Scale and an interview querying athletes’ retrospective symptoms over time, starting immediately postinjury. Results: Descriptive statistics revealed that the most common immediate symptoms following concussion include dizziness (endorsed by 83.6% of the sample), headache (65.5%), feeling in a fog (61.8%), and visual disturbance (60.0%). Logistic regression analyses indicated that retrograde and anterograde amnesia, as well as loss of consciousness, were not significantly predictive of postconcussion symptoms within one week following concussion (p > .05). However, the total symptom score assessed immediately postinjury, in addition to endorsing immediate headache symptoms following concussion, reliably predicted a higher level of symptom reporting in the first week following concussion (p < .05). Finally, receiver-operating characteristic (ROC) curve analysis, using 80% sensitivity to predict the high postconcussion symptom group, established cutoff scores of 7.5 for the immediate total symptom score and 0.5 for immediate headache. Conclusions: These findings demonstrate the importance of evaluating symptoms immediately following concussion. Athletes who endorse more immediate postconcussion symptoms, especially headache symptoms, may be at risk for greater and more severe postconcussion symptoms within the first week following concussion. The present findings have implications for the management and treatment of sports-related concussions.

Recent advances in the treatment of alcoholism

Abstract Alcoholism is a major public health problem, and a devastating disorder for affected individuals, their families, and society. We have made great gains in the past 25 years in understanding and treating alcoholism. A recent and important treatment advance is the use of pharmacotherapies that improve treatment response for many patients beyond what they obtain from counseling. We have gained a better understanding of the neurobiology associated with alcoholism, pharmacological treatments can be targeted to numerous pathways affected by chronic and excessive alcohol drinking. Consequently, an increased number of investigational studies of new compounds that are meant to reduce alcohol craving and drinking have emerged in the literature. There are three medications that have been approved in the United States (US) by the Food and Drug Administration (FDA) for the treatment of alcohol dependence: disulfiram, naltrexone, and acamprosate. Many more are being used in Canada, Europe, Australia and other parts of the world for treating alcohol dependence. Studies have also examined best practices in prescribing medications. For example, it has been empirically demonstrated that patient non-adherence to treatment diminishes the treatments value. In turn, we can improve treatment response if we proactively provide patients with strategies to help them take their medications and attend their counseling visits. Other important advances related to pharmacotherapy are that alcoholic subgroups differentially respond to specific pharmacotherapies, and combining two pharmacotherapies that address different neurobiological systems simultaneously to treat alcohol dependence may prove more beneficial than a single medication in some patient groups.

Reading Based IQ Estimates and Actual Premorbid Cognitive Performance: Discrepancies in a College Athlete Sample

The present study sought to evaluate the Wechsler Test of Adult Reading (WTAR) Full-Scale IQ (FSIQ) estimate as an index of premorbid ability in a sample 574 of healthy college athletes participating in a sports concussion management program. We compared baseline neuropsychological test performance with the WTAR FSIQ estimate obtained at baseline. Results revealed that the discrepancy between actual neuropsychological test scores and the WTAR FSIQ estimate was greatest for those with estimated FSIQs greater than 107. The clinical implication of this finding was evaluated in the 51 participants who went on to sustain a concussion. For individuals with higher IQ estimates, the WTAR estimate obtained post-concussion suggested greater post-concussion decline than that indicated by comparison with actual baseline neuropsychological performance.

Neurovegetative symptoms in patients with multiple sclerosis: Fatigue, not depression

Elucidating the relationship between fatigue and depression in multiple sclerosis (MS) patients is complicated by ambiguity regarding how these two constructs should be delineated. Neurovegetative symptoms of depression may reflect depression in MS patients, as they do in non-neurological populations; instead these items may measure disease-related fatigue; or disease-related fatigue and depression may reflect the same syndrome in MS patients. The present study sought to evaluate these possibilities by characterizing the underlying factor structure of self-report items designed to measure fatigue and depression symptoms. Questionnaires designed to measure fatigue and depression were administered to 174 MS patients and 84 healthy controls, and these items were subject to factor analysis. Results suggest that neurovegetative symptoms are poor indicators of depression in MS patients. Neurovegetative depression items were removed from the final model due to poor psychometric properties, or they loaded on Fatigue or Sleep Disturbance factors. The correlation between latent factors Depression and Fatigue was large (.47), but does not indicate that these phenomena are manifestations of the same construct. Hence, the results of this study support the notion that vegetative symptoms of depression do not reflect depression in MS patients, but instead measure symptoms of fatigue and sleep disturbance.

The influence of the apolipoprotein E (APOE) gene on subacute post-concussion neurocognitive performance in college athletes

Objective The purpose of this study was to determine whether the ε4 allele of the APOE gene influences neurocognitive outcome following sports-related concussion. It was hypothesized that participants with an ε4 allele would show poorer neurocognitive performance and greater neurocognitive variability than those without an ε4 allele. Method Participants included 57 concussed collegiate athletes (77.2% male) who participated in a concussion management program at a large university. All athletes underwent a comprehensive neuropsychological assessment and provided a DNA sample for determination of their APOE genotype. The test battery included measures sensitive to concussion, covering the broad domains of learning and memory, attention, processing speed, and executive functions. Results The sample was divided into ε4 + (n = 20) and ε4 - (n = 37) groups. No significant differences were found between athletes with and without an ε4 allele when examining mean neurocognitive standardized scores (all p > .05; d = 0.16-0.18). However, athletes with an ε4 allele were more likely to show a greater number of impaired neurocognitive scores post-injury compared to athletes without an ε4 allele, χ2(1, N = 57) = 3.96, p = < .05, φ = 0.26. Additionally, athletes with an ε4 allele demonstrated greater neurocognitive variability than athletes without an ε4 allele, t(55) = -2.04, p < .05, d = 0.53. Conclusions This research furthers our understanding of how genetic factors uniquely contribute to neurocognitive performance differences following concussion. Our findings suggest a possible relationship between the ε4 allele and post-concussion impairment, as well as between the ε4 allele and neurocognitive performance variability, suggesting that the ε4 genotype may be a risk factor for less efficient cognitive processing in concussed athletes.