Faculty Bibliography

CONTEXT: Approximately 300 000 sport-related concussions occur annually in the United States, and the likelihood of serious sequelae may increase with repeated head injury. OBJECTIVE: To estimate the incidence of concussion and time to recovery after concussion in collegiate football players. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of 2905 football players from 25 US colleges were tested at preseason baseline in 1999, 2000, and 2001 on a variety of measures and followed up prospectively to ascertain concussion occurrence. Players injured with a concussion were monitored until their concussion symptoms resolved and were followed up for repeat concussions until completion of their collegiate football career or until the end of the 2001 football season. MAIN OUTCOME MEASURES: Incidence of concussion and repeat concussion; type and duration of symptoms and course of recovery among players who were injured with a concussion during the seasons. RESULTS: During follow-up of 4251 player-seasons, 184 players (6.3%) had a concussion, and 12 (6.5%) of these players had a repeat concussion within the same season. There was an association between reported number of previous concussions and likelihood of incident concussion. Players reporting a history of 3 or more previous concussions were 3.0 (95% confidence interval, 1.6-5.6) times more likely to have an incident concussion than players with no concussion history. Headache was the most commonly reported symptom at the time of injury (85.2%), and mean overall symptom duration was 82 hours. Slowed recovery was associated with a history of multiple previous concussions (30.0% of those with > or =3 previous concussions had symptoms lasting >1 week compared with 14.6% of those with 1 previous concussion). Of the 12 incident within-season repeat concussions, 11 (91.7%) occurred within 10 days of the first injury, and 9 (75.0%) occurred within 7 days of the first injury. CONCLUSIONS: Our study suggests that players with a history of previous concussions are more likely to have future concussive injuries than those with no history; 1 in 15 players with a concussion may have additional concussions in the same playing season; and previous concussions may be associated with slower recovery of neurological function.

This study provides preliminary norms and test-retest indices on a brief battery of neuropsychological tests administered to a sample of 60 male and 40 female high school athletes. Forty-eight subjects completed retesting 8 weeks later. Analyses of baseline scores indicate that girls outperform boys on selected measures of processing speed and executive functions [Wechsler Adult Intelligence Scale-III (WAIS-III) Digit Symbol, Trails B, and Controlled Oral Word Association Test (COWAT)]. Test-retest reliability was low and varied widely among the tests. There were no gender differences in test-retest reliability. Reliable Change Indices (RCIs) were computed on the test-retest data for use in clinical interpretation. These preliminary results indicate that caution should be used in interpreting neuropsychological test data from high school athletes. The current findings indicate that separate norms for boys and girls are warranted. Caution should be used in interpreting discrepancies from baseline scores as a result of what may turn out to be poor test-retest reliability in this population

CONTEXT: Lack of empirical data on recovery time following sport-related concussion hampers clinical decision making about return to play after injury. OBJECTIVE: To prospectively measure immediate effects and natural recovery course relating to symptoms, cognitive functioning, and postural stability following sport-related concussion. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of 1631 football players from 15 US colleges. All players underwent preseason baseline testing on concussion assessment measures in 1999, 2000, and 2001. Ninety-four players with concussion (based on American Academy of Neurology criteria) and 56 noninjured controls underwent assessment of symptoms, cognitive functioning, and postural stability immediately, 3 hours, and 1, 2, 3, 5, 7, and 90 days after injury. MAIN OUTCOME MEASURES: Scores on the Graded Symptom Checklist (GSC), Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and a neuropsychological test battery. RESULTS: No player with concussion was excluded from participation; 79 players with concussion (84%) completed the protocol through day 90. Players with concussion exhibited more severe symptoms (mean GSC score 20.93 [95% confidence interval [CI], 15.65-26.21] points higher than that of controls), cognitive impairment (mean SAC score 2.94 [95% CI, 1.50-4.38] points lower than that of controls), and balance problems (mean BESS score 5.81 [95% CI, -0.67 to 12.30] points higher than that of controls) immediately after concussion. On average, symptoms gradually resolved by day 7 (GSC mean difference, 0.33; 95% CI, -1.41 to 2.06), cognitive functioning improved to baseline levels within 5 to 7 days (day 7 SAC mean difference, -0.03; 95% CI, -1.33 to 1.26), and balance deficits dissipated within 3 to 5 days after injury (day 5 BESS mean difference, -0.31; 95% CI, -3.02 to 2.40). Mild impairments in cognitive processing and verbal memory evident on neuropsychological testing 2 days after concussion resolved by day 7. There were no significant differences in symptoms or functional impairments in the concussion and control groups 90 days after concussion. CONCLUSIONS: Collegiate football players may require several days for recovery of symptoms, cognitive dysfunction, and postural instability after concussion. Further research is required to determine factors that predict variability in recovery time after concussion. Standardized measurement of postconcussive symptoms, cognitive functioning, and postural stability may enhance clinical management of athletes recovering from concussion

OBJECTIVE: To examine the independent contribution of executive versus semantic function to improvement in formal thought disorder after initial stabilization in a first-episode sample. BACKGROUND: Neurocognitive deficits have been suggested to predict treatment response in patients with first-episode schizophrenia. However, studies targeting putative neurocognitive mechanisms to explore improvement in positive psychotic symptoms and especially formal thought disorder are lacking. METHOD: Formal thought disorder symptoms in 81 first-episode patients with schizophrenia or schizoaffective disorder either showed significant improvement (responders > 60% change) or not (nonresponders < 60%) 6 months after initial stabilization of symptoms. These two groups were compared on neuropsychologic (n = 16), clinical (n = 15), and volumetric measures of the frontal and temporal lobes (n = 5) in univariate analyses. The variables that significantly differed between these two groups were used in a forward binary logistic regression analysis. RESULTS: As compared with nonresponders, responders were younger at time of testing, had higher verbal intelligence and reading achievement scores, higher scores on the arithmetic subtest of the Wechsler Adult Intelligence Scale-Revised, and lower number of perseverative responses on the Wisconsin Card Sort Test. Responders also had larger frontal lobe volumes than nonresponders. Only two measures (perseverative responses on the Wisconsin Card Sort Test and age at testing) entered the regression equation. Measures of semantic competency and volumetric measures of the temporal lobes were not associated with formal thought disorder improvement. CONCLUSIONS: Neurocognitive deficits are associated with treatment response in formal thought disorder in first-episode patients with schizophrenia. The improvement in formal thought disorder is more strongly linked to executive than semantic function in this sample, pointing to the salience of frontal systems in treatment response in positive psychotic symptoms.

BACKGROUND: Myoclonus-dystonia (M-D) is a movement disorder with involuntary jerks and dystonic contractions. Autosomal dominant alcohol-responsive M-D is associated with mutations in the epsilon-sarcoglycan gene (SGCE) (six families) and with a missense change in the D2 dopamine receptor (DRD2)gene (one family). OBJECTIVE: To investigate the clinical phenotype associated with M-D including motor symptoms, psychiatric disorders, and neuropsychological deficits. METHODS: Fifty individuals in three M-D families were evaluated and a standardized neurologic examination and DNA analysis were performed. Psychiatric profiles were established with the Diagnostic Interviews for Genetic Studies (DIGS) and the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Cognition was evaluated with standardized neuropsychological tests. RESULTS: Distinct truncating mutations in the SGCE gene were identified in each family. Additionally, a missense alteration in the DRD2 gene was previously found in one family. Motor expression was variable, with onset of myoclonus or dystonia or both affecting the upper body and progression to myoclonus and dystonia in most cases. Psychiatric profiles revealed depression, obsessive-compulsive disorder, substance abuse, anxiety/panic/phobic disorders, and psychosis in two families, and depression only in the third family. Averaged scores from cognitive testing showed impaired verbal learning and memory in one family, impaired memory in the second family, and no cognitive deficits in the third family. CONCLUSIONS: Cognitive deficits may be associated with M-D. Psychiatric abnormalities correlate with the motor symptoms in affected individuals. Assessment of additional M-D families with known mutations is needed to determine whether these are characteristic phenotypic manifestations of M-D.

Neuropsychological (NP) testing is now recognized as an important method for evaluating treatment effects. However, there are limitations to how these tests are currently used in most drug treatment protocols. Changes in cognition are typically defined in statistical terms, with little knowledge as to whether the observed differences are meaningful in any other sense. Methods for assessing changes in test scores need to account for test-retest reliability, practice effects, regression to the mean, and the impact of initial performance. All of these factors may vary according to the individual characteristics of the subject. This article reviews two methods from the NP literature that have attempted to account for these sources of test-retest bias. The reliable change index provides a confidence interval for predicted change by taking into account the test-retest reliability of the measure. Standardized regression-based measures use a more sophisticated statistical approach that enables them to better account for other potential sources of confound. Use of this methodology has been limited to studies of epilepsy surgery and sports-related concussion. These methods have the potential for enhancing the interpretation of NP test data in drug treatment protocols by providing an empirically based definition of clinically meaningful change