Chronic Traumatic Encephalopathy (CTE) Is Absent From a European Community-Based Aging Cohort While Cortical Aging-Related Tau Astrogliopathy (ARTAG) Is Highly Prevalent

This study determined the prevalence of chronic traumatic encephalopathy (CTE) and cortical aging-related tau astrogliopathy (ARTAG) in a European community-based population (n = 310). The frontal, parietal, and temporal cortices, representing initial stages of CTE were assessed. No case fulfilling CTE consensus criteria was found. However, isolated astroglial or neuronal tau pathologies were recognized in the depths of cortical sulci (<2%). A single case (female, 85 years) without a history of traumatic brain injury (TBI) showed combined tau-immunoreactive features confined to frontal sulci without perivascular accumulation. Another 24 cases had single tau pathologies in cortical sulci. ARTAG was identified in 117 cases (38%), with a similar regional prevalence. Gray matter ARTAG was the most common followed by subpial, white matter, and perivascular. The presence of any type of ARTAG was strongly associated with having another type of ARTAG in the same region (p < 0.05). In summary, although isolated tau pathologies in the depths of cortical sulci were identified, no case fulfilled diagnostic criteria of CTE. Cortical ARTAG in this population is common and contrasts the high prevalence of CTE in individuals with repeated mild TBI. ARTAG in isolation might not be indicative of CTE although commonalities in pathogenesis should be considered.