Genetic polymorphisms associated with the risk of concussion in 1056 college athletes: a multicentre prospective cohort study.

BACKGROUND/AIM: To evaluate the association of genetic polymorphisms APOE, APOE G-219T promoter, microtubule associated protein(MAPT)/tau exon 6 Ser53Pro, MAPT/tau Hist47Tyr, IL-6572 G/C and IL-6RAsp358Ala with the risk of concussion in college athletes. METHODS: A 23-centre prospective cohort study of 1056 college athletes with genotyping was completed between August 2003 and December 2012. All athletes completed baseline medical and concussion questionnaires, and post-concussion data were collected for athletes with a documented concussion. RESULTS: The study cohort consisted of 1056 athletes of mean±SD age 19.7±1.5 years, 89.3% male, 59.4% Caucasian, 35.0% African-American, 5.6% other race. The athletes participated in American football, soccer, basketball, softball, men's wrestling and club rugby. A total of 133 (12.1% prevalence) concussions occurred during an average surveillance of 3 years per athlete. We observed a significant positive association between IL-6R CC (p=0.001) and a negative association between APOE4 (p=0.03) and the risk of concussion. Unadjusted and adjusted logistic regression analysis showed a significant association between IL-6R CC and concussion (OR 3.48; 95% CI 1.58 to 7.65; p=0.002) and between the APOE4 allele and concussion (OR 0.61; 95% CI 0.38 to 0.96; p=0.04), which persisted after adjustment for confounders. CONCLUSIONS: IL-6R CC was associated with a three times greater concussion risk and APOE4 with a 40% lower risk.

Exposure to sub-concussive head injury in boxing and other sports.

BACKGROUND: Current characterizations of chronic traumatic brain injury (CTBI) in boxing, football and other sports are reviewed in the context of the history of research on sub-concussive brain trauma in athletes. METHODS: The utility of exposure models for understanding CTBI in boxers is examined and concerns regarding the paucity of findings supportive of an exposure model for CTBI in football players are discussed. RESULTS AND CONCLUSIONS: Recommendations for development of exposure models for sport-specific phenotypic characterizations of CTBI are presented.

Reliability of a cognitive endpoint for use in a multiple sclerosis pharmaceutical trial.

OBJECTIVE: Determine reliability and basic psychometric properties of a composite cognitive endpoint, MS-COG, for monitoring change in cognitive function in MS drug trials. BACKGROUND: 50% of MS patients have cognitive impairment that impacts ability to work and quality of life. We selected neuropsychological tests based on sensitivity to MS cognitive impairment, availability of alternate forms, cross-cultural utility, and feasibility for multicenter trials, and assessed the reliability and validity of a composite endpoint, MS-COG. DESIGN/METHODS: Administered SRT, BVMT-R, PASAT, and SDMT to 60 MS patients at 4 US centers twice over 45days, along with symptom inventories by patients and informants. RESULTS: The MS-COG had test-retest reliability of 0.91. Processing Speed and Memory indices had reliabilities of 0.89 and 0.86, with modest practice effects. Reliability was high for the RR MS and SP MS subgroups as well, with correlations of .90 and .93, respectively for MS-COG. Overall, 42% of subjects obtained MS-COG scores in the impaired range, with SP MS subjects performing 0.8 SD below RR MS subjects. Impairment correlated well (r=0.37 to 0.40) with informant reports but was inconsistent with patient report, with the least reliable assessments by those with greater symptom severity. CONCLUSIONS: The MS-COG is a reliable, repeatable measure of MS cognitive functioning that is sensitive to cognitive impairment in SP MS and RR MS patients and feasible for multicenter clinical trials. Further development is warranted.

Development and validation of a web-based screening tool for monitoring cognitive status.

OBJECTIVES: We acquired normative data for an Internet neurocognitive screening tool, the Cognitive Stability Index (CSI), and investigated its validity both for initial assessment and for detecting significant change. PARTICIPANTS: Normative data on a nationally representative sample of 284 individuals aged 18 to 89. Validity data was obtained for outpatient groups of mild-to-moderate TBI, attention deficit/hyperactivity disorder (AD/HD), and Alzheimer's disease. RESULTS: The CSI subtests resolve to four factors: attention, processing speed, motor speed, and memory with acceptable psychometric properties. Patterns of scores obtained by three groups of patient-participants provided reasonable evidence of clinical validity for screening and monitoring change. CONCLUSIONS: An Internet-based system holds promise for applying complex statistical models for routine monitoring of cognitive function.