Mild Cognitive Impairment in Retired Professional Football Players With a History of Mild Traumatic Brain Injury: A Pilot Investigation.

BACKGROUND: Traumatic brain injury (TBI) is a known risk factor for neurodegenerative dementias such as Alzheimer disease (AD); however, the potential risk of mild cases of TBI, such as concussions, remains unclear. OBJECTIVE: To explore whether a small sample of retired professional athletes with a diagnosis of mild cognitive impairment (MCI)-the prodromal stage of AD-and a history of multiple mild TBIs exhibit greater neuropsychological impairment than age-matched nonathletes with MCI and no history of TBI. METHOD: Ten retired National Football League players diagnosed with MCI and reporting multiple mild TBIs, and 10 nonathletes, also diagnosed with MCI but with no history of TBI, completed a standard neurologic examination and neuropsychological testing. Independent samples t tests were conducted to examine differences in neuropsychological performance between the two groups. RESULTS: The retired athletes with a history of mild TBI obtained generally similar scores to the nonathlete controls on measures of verbal learning and memory, verbal fluency, and processing speed. However, the retired athletes scored lower than the controls on tests of confrontation naming and speeded visual attention. CONCLUSION: Retired athletes with MCI and a history of mild TBI demonstrated similar neuropsychological profiles as nonathlete controls despite lower scores on measures of confrontation naming and speeded visual attention. These findings suggest that a history of multiple mild TBIs does not significantly alter the overall neuropsychological profile of individuals with MCI; confirmation of this will require longitudinal research with larger sample sizes.

Occurrence, plausibility, and desirability for 124 Life Events Inventory items.

Imagination inflation is where imaginative elaboration of possible childhood experiences inflates (increases) participants' estimation that these events actually occurred, as indicated by pre- to post-manipulation ratings changes. This research primarily uses the Life Events Inventory (LEI), listing possible experiences that could have happened during childhood (Garry, Manning, Loftus, & Sherman, Psychonomic Bulletin & Review, 3, 208-214, 1996). Although imagination inflation research has spawned more than 50 investigations, no normative ratings exist on individual items contained in the LEI. To address this, we present descriptive statistics (mean, median, standard deviation, confidence interval) for 124 LEI items on occurrence (how likely is it that this experience happened to you), plausibility (how plausible is it that this event could have happened to someone), and desirability (how desirable is this experience). Occurrence and plausibility showed similar patterns of mean item ratings and were highly correlated, whereas desirability was moderately correlated with plausibility and unrelated to occurrence. These data should facilitate a more informed selection of specific LEI items to use in further research and can assist in clarifying the contributions of normative occurrence, plausibility, and desirability to imagination inflation effects.

White Matter Changes and Confrontation Naming in Retired Aging National Football League Athletes.

Using diffusion tensor imaging (DTI), we assessed the relationship of white matter integrity and performance on the Boston Naming Test (BNT) in a group of retired professional football players and a control group. We examined correlations between fractional anisotropy (FA) and mean diffusivity (MD) with BNT T-scores in an unbiased voxelwise analysis processed with tract-based spatial statistics (TBSS). We also analyzed the DTI data by grouping voxels together as white matter tracts and testing each tract's association with BNT T-scores. Significant voxelwise correlations between FA and BNT performance were only seen in the retired football players (p < 0.02). Two tracts had mean FA values that significantly correlated with BNT performance: forceps minor and forceps major. White matter integrity is important for distributed cognitive processes, and disruption correlates with diminished performance in athletes exposed to concussive and subconcussive brain injuries, but not in controls without such exposure.