Chronic traumatic encephalopathy pathology in a neurodegenerative disorders brain bank

Abstract

Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disorder linked to repetitive traumatic brain injury (TBI) and characterized by deposition of hyperphosphorylated tau at the depths of sulci. We sought to determine the presence of chronic traumatic encephalopathy (CTE) pathology in a brain bank for neurodegenerative disorders for individuals with and without a history of contact sports participation. Available medical records of 1,721 men were reviewed for evidence of past history of injury or participation in contact sports. Subsequently, cerebral cortical samples were processed for tau immunohistochemistry in cases with a documented history of sports exposure as well as age- and disease-matched men and women without such exposure. For cases with available frozen tissue, genetic analysis was performed for variants in APOE, MAPT, and TMEM106B. Immunohistochemistry revealed 21 of 66 former athletes had cortical tau pathology consistent with CTE. CTE pathology was not detected in 198 individuals without exposure to contact sports, including 33 individuals with documented single-incident TBI sustained from falls, motor vehicle accidents, domestic violence, or assaults. Among those exposed to contact sports, those with CTE pathology did not differ from those without CTE pathology with respect to noted clinicopathologic features. There were no significant differences in genetic variants for those with CTE pathology, but we observed a slight increase in MAPT H1 haplotype, and there tended to be fewer homozygous carriers of the protective TMEM106B rs3173615 minor allele in those with sports exposure and CTE pathology compared to those without CTE pathology. In conclusion, this study has identified a small, yet significant, subset of individuals with neurodegenerative disorders and concomitant CTE pathology. CTE pathology was only detected in individuals with documented participation in contact sports. Exposure to contact sports was the greatest risk factor for CTE pathology. Future studies addressing clinical correlates of CTE pathology are needed.

Traumatic Brain Injury As a Risk Factor for Alzheimer’s Disease: Current Knowledge and Future Directions

“…In 2005, a syndrome of progressive cognitive, motor and neuropsychiatric symptoms initially described almost 80 years prior [1,2] found renewed interest when these symptoms were described in two professional American football players whose brains showed an apparently unique distribution of tau pathology, or neurofibrillary tangles (NFTs) [3,4]. This tauopathy called chronic traumatic encephalopathy (CTE) has since been identified postmortem in a small but growing number of individuals [4][5][6][7], resulting in widespread media attention and public health concern about the possible neurodegenerative effects of TBI. Based on preliminary neuropathological diagnostic published earlier this year [8], CTE has thus far only been found postmortem in individuals who were exposed to repetitive concussive or subconcussive head trauma during life [6].…”

“…This tauopathy called chronic traumatic encephalopathy (CTE) has since been identified postmortem in a small but growing number of individuals [4][5][6][7], resulting in widespread media attention and public health concern about the possible neurodegenerative effects of TBI. Based on preliminary neuropathological diagnostic published earlier this year [8], CTE has thus far only been found postmortem in individuals who were exposed to repetitive concussive or subconcussive head trauma during life [6]. However, the link between single TBI and dementia has been a topic of interest among researchers and clinicians for decades.…”

Dementia After Moderate-Severe Traumatic Brain Injury: Coexistence of Multiple Proteinopathies

“…A recent reexamination of 1,721 specimens in a neurodegenerative brain bank found CTE changes in 21 of 66 former athletes with repetitive mild TBIs during sports participation ranging from high school to professional levels and no CTE changes among 198 controls or 33 cases with a history of remote single TBI. The majority (20/21) of the CTE cases were also diagnosed with at least 1 other neurodegenerative disorder (6 with AD, 4 with AD and DLB, 3 with ALS, 3 with DLB, 3 with FTLD-tau, and 1 with FTLD-FUS) (48).…”

Long-Term Cognitive and Neuropsychiatric Consequences of Repetitive Concussion and Head-Impact Exposure

“…57 However, the role of phosphorylated s in the genesis of the clinical syndrome is not yet clear. Bieniek et al 58 reported findings of a neuropathologic investigation of the brains of 66 individuals exposed to contact sports, such as football, drawn from a brain bank for neurodegenerative disorders. Twenty-one individuals met the pathologic criteria for CTE, compared with 0 individuals from the group of 198 individuals without contact-sport exposure.…”