Balcer, Laura J.

AbstractINTRODUCTIONTau is a key pathology in chronic traumatic encephalopathy (CTE). Here, we report our findings in tau positron emission tomography (PET) measurements from the DIAGNOSE CTE Research Project.METHODWe compare flortaucipir PET measures from 104 former professional players (PRO), 58 former college football players (COL), and 56 same‐age men without exposure to repetitive head impacts (RHI) or traumatic brain injury (unexposed [UE]); characterize their associations with RHI exposure; and compare players who did or did not meet diagnostic criteria for traumatic encephalopathy syndrome (TES).RESULTSSignificantly elevated flortaucipir uptake was observed in former football players (PRO+COL) in prespecified regions (p < 0.05). Association between regional flortaucipir uptake and estimated cumulative head impact exposure was only observed in the superior frontal region in former players over 60 years old. Flortaucipir PET was not able to differentiate TES groups.DISCUSSIONAdditional studies are needed to further understand tau pathology in CTE and other individuals with a history of RHI.

AbstractBackgroundChronic traumatic encephalopathy (CTE) is a neurodegenerative disease that is characterized by perivascular foci of phosphorylated tau (p‐tau) notably in the depths of sulci, with varying patterns in the cerebral cortex. Prior studies show elevated flortaucipir (FTP) PET binding in former American professional football players(PRO). However, the association of p‐tau with clinical measures remains unclear using regional FTP SUVR as early signs of CTE related tau pathology. Graph theory (GT) takes advantages of the spatial variability in p‐tau load and allows the integration of regional measures to define GT based measures. Here we examine the GT based measures in two CTE cohorts to evaluate their utility in assessing p‐tau related pathology in CTE.MethodThe graph procedure was optimized in FTP PET images in a group of 26 PRO with reported cognitive and/or behavorial symptoms and 30 asymptomatic controls without a history of traumatic brain injury (the DETECT Study) and identified the GT measure, entorhinal tau strength, as the target metric with the best group separation between PRO and controls. The optimized graph procedures were then applied to the DIAGNOSE CTE Research Project dataset (99 former PRO, 51 former college football players [COL], and 52 controls without exposure to repetitive head impacts [CTL]) and we examined entorhinal tau strength’s ability to differentiate the exposure groups and relationship to consensus based diagnoses of Traumatic Encephalopathy Syndrome (TES), the clinical syndrome associated with CTE.ResultEntorhinal tau strength was significantly different among the three exposure groups (p=0.0001) similar to regional SUVR measures (Figure 1). Regional SUVR did not differentiate players (PRO+COL) with and without TES, while entorhinal tau strength approached although did not reach significance (Figure 2). Entorhinal tau strength is the only FTP measure that showed significant differences (p=0.006) between those players with cognitive impairment and players without (Figure 3).ConclusionWhile there is still considerable overlap in between‐group measurements, GT based entorhinal tau strength, is potentially more sensitive in detecting tau changes in players with and without TES. Additional studies are necessary to clarify the value of this new measure in detecting underlying CTE pathology.

AbstractIntroductionThe presentation, risk factors, and etiologies of white matter hyperintensities (WMH) in people exposed to repetitive head impacts are unknown. We examined the burden and distribution of WMH, and their association with years of play, age of first exposure, and clinical function in former American football players.MethodsA total of 149 former football players and 53 asymptomatic unexposed participants (all men, 45–74 years) completed fluid‐attenuated inversion recovery magnetic resonance imaging, neuropsychological testing, and self‐report neuropsychiatric measures. Lesion Segmentation Toolbox estimated WMH. Analyses were performed in the total sample and stratified by age 60.ResultsIn older but not younger participants, former football players had greater total, frontal, temporal, and parietal log‐WMH compared to asymptomatic unexposed men. In older but not younger former football players, greater log‐WMH was associated with younger age of first exposure to football and worse executive function.DiscussionIn older former football players, WMH may have unique presentations, risk factors, and etiologies.Highlights Older but not younger former football players had greater total, frontal, temporal, and parietal lobe white matter hyperintensities (WMH) compared to same‐age asymptomatic unexposed men. Younger age of first exposure to football was associated with greater WMH in older but not younger former American football players. In former football players, greater WMH was associated with worse executive function and verbal memory.

AbstractBackgroundLittle is known about sleep in those with a history of contact sports, who are at increased risk for neurodegenerative disease(s). Sleep disruption and disorders are increasingly recognized as having a bidirectional relationship with Alzheimer’s disease neuropathology. Here, we investigated self‐reported sleep disruption and disorders in male former college and professional American football players.Method116 former National Football League (NFL) players, 60 former college football players, and 60 asymptomatic men without a history of traumatic brain injury or repetitive head impacts (controls), all between 45‐74 years, completed the Mayo Sleep Questionnaire (MSQ) which includes the Epworth Sleepiness Scale (ESS). Former American football players were enrolled across the spectrum of symptom severity (asymptomatic to mild dementia). Using binary logistic regression or analysis of covariance, comparisons (controlling for age, racial identity, body mass index, APOE e4 status) on each of the MSQ items and the ESS were made between each of the study groups.ResultCompared to controls, former NFL players were more likely to restless legs (OR = 7.32, 95% CI = 1.63‐32.97*), sleepwalking (OR = 8.65, 95% CI = 1.08‐69.22*), observed apnea (OR = 2.25, 95% CI = 1.04‐4.85*), lower alertness levels (marginal mean diff. = 0.90**) and had higher ESS (marginal mean diff. = 2.37**). Former college football players reported greater sleep disturbances compared with controls: restless legs (OR = 10.82, 95% CI = 1.86‐62.89**), sleepwalking (OR = 10.45, 95% CI = 1.12‐97.58*), alertness levels (marginal mean diff. = 1.48**) and ESS (marginal mean diff. = 2.76*). There were no college vs control differences for observed apnea. There were no differences between former NFL players and former college football players on any sleep metric. **p<.005, *p<.05.ConclusionSleep disturbances may be an important factor to investigate in those with a history of participation in American football.

AbstractBackgroundRepetitive head impacts from American football have been associated with long‐term cognitive symptoms. The late neuropsychological profiles of this population is not well‐characterized. Research has relied on retrospective informant reports and/or has been small samples of former professional players. We describe objective neuropsychological test performance in former college and professional American football players.MethodsMale (45‐74 years) former National Football League (n=107) and college football players (n=59) from the DIAGNOSE‐CTE Research Project completed a neuropsychological test battery, Functional Activities Questionnaire (FAQ) and Quick Dementia Rating Scale (QDRS). Neuropsychological test scores were converted to T‐scores using age, sex, and/or education‐adjusted normative data. T‐scores<35 defined impairment. Participants were enrolled across the spectrum of symptom severity (asymptomatic to dementia). Individuals without decisional capacity were excluded. Participants with missing data (n=4) and who scored <45 on Test of Memory Malingering Trial 2 (n=10) were excluded.Results108 (65.1%) identified as White and 53 (31.9%) as Black. Mean education years was 16.76 (SD=1.48). Fourteen (8.4%) and 6 (3.6%) reported diagnostic history of ADHD and learning disability, respectively. Average Montreal Cognitive Assessment score was 24.96 (SD=3.17); 85 (51.2%) scored <26. Impairment rates were highest for learning and episodic memory. On Neuropsychological Assessment Battery List Learning, 29.5% were impaired on Immediate recall, 36.1% on Short Delay, and 44.0% on Long Delay Recall. Impairment rates for Craft Story Immediate and Delayed Recall (Paraphrase) were 15.7% and 18.7%, respectively. 19.9% and 15.7% were impaired on learning and delayed recall of the Brief Visuospatial Memory Test‐Revised. Impairments were frequent on the Multilingual Naming Test (20.5%), Trail Making Test Parts B (19.3%) and A (18.1%), Animal Fluency (15.7%), and Number Span Backward (15.1%). Impairments were less common (<10%) for phonemic fluency, planning, basic attention, and visual‐perceptual abilities, Mean FAQ was 3.11 (SD=5.14); 23 (13.9%) had an FAQ >9. Based on QDRS scores, 66 (39.8%) had mild cognitive impairment, 44 (26.5%) mild dementia, and 6 (3.6%) moderate dementia.ConclusionsIn these former American football players, neuropsychological impairments were most frequent in episodic memory, followed by confrontation naming and executive function. Further research is needed to delineate this population’s unique neuropsychological profile.