Chronic traumatic encephalopathy in a neuropathologically confirmed Creutzfeldt-Jakob disease cohort.

Chronic traumatic encephalopathy (CTE) is a tauopathy associated with repetitive head impacts, experienced most commonly in contact sports; however, its relationship with prion diseases remains unclear. Postmortem CTE screening using phosphorylated tau staining was conducted at the Neurological Tissue Bank of Hospital Clínic-IDIBAPS on hippocampal and frontal cortex samples from patients with neuropathologically confirmed Creutzfeldt-Jakob disease (CJD), blinded to patients' clinical histories. In positive and suggestive cases, the analysis was expanded in accordance with the NINDS/NIBIB consensus criteria for CTE, and clinical and neuropathological information was reviewed. CTE was detected in 3 out of 212 CJD cases (1.4%), all with severe CTE pathology: 2 former soccer players (one of them an elite player) and 1 former rugby player. All had started playing sports between the first and second decades of life and ended in the fifth. The clinical presentation of CJD was heterogeneous, with different initial symptoms in each case. Neuropathological examination revealed an MM1/MV1 histotype in the soccer players and a VV2 histotype in the rugby player, the first- and second-most common variants in CJD, respectively. These three cases illustrate the coexistence of CTE and CJD across heterogeneous clinicopathological presentations. Further studies are needed to determine whether shared mechanisms may contribute to the coexistence of both pathologies.