Figure 2.

Tau and amyloid-β pathology after TBI. a,b | Extensive neurofibrillary tangles observed in a boxer.¹⁸ The 77-year-old man had participated in over 700 boxing contests during his life and had neuropsychiatric symptoms. Tangles were identified using silver staining (a) and Congo red staining (b). c,d | Neurofibrillary tangles in the parahippocampal gyrus of a 47-year-old man who had sustained a single severe TBI 1 year previously.⁸⁸ No history of repetitive TBI was recorded. Tangles were identified using immunohistochemistry (c) and thioflavine S staining (d). Scale bars 100 μm. e,f | Sections of the temporal cortex from a 63-year-old man with dementia pugilistica⁵⁷ who had participated in over 300 boxing contests and was originally noted as plaque-negative.¹⁸ Extensive amyloid-β plaques were demonstrated using immunohistochemistry with formic acid pretreatment (e), but not with Congo red (f). Abbreviation: TBI, traumatic brain injury. Permission for parts a and b obtained from Cambridge University Press © Corsellis, J. A. et al. Psychol. Med. 3, 270–303 (1973). Permission for parts c and d obtained from John Wiley and Sons © Johnson, V. E. et al. Brain Pathol. 22, 142–149 (2012). Parts e and f reproduced from Roberts, G. W. et al. The occult aftermath of boxing. J. Neurol. Neurosurg. Psychiatry 53, 373–378 © 1990 with permission from BMJ Publishing Group Ltd.