Bell WR, et al. - Researchers compared subjects with primary age-related tauopathy (PART) and Alzheimer's disease (AD) pathology regarding neuropathological features, tau haplotypes, apolipoprotein E (APOE) genotypes, and cognitive profiles. PART subjects displayed significantly slower rates of decline on measures of memory, language, and visuospatial performance compared to those noted for AD subjects. Further, these subjects displayed lower APOE ε4 allele frequency. PART is thus identified as separate from AD. This suggests the significance of its distinction for the clinical management of patients with cognitive impairment and for public health care planning.