MAPT and Alzheimer disease: To test the feasibility of this approach for a wide range of cognitive impairment severities, we included patients with minimal cognitive impairment (Mini Mental State Examination (MMSE) score lower than 29 but higher than 24) up until manifest dementia (MMSE score 24 and lower) and defined the presence of AD by a pathological Total tau/Aβ(1–42) ratio (TB ratio) in the CSF, which is still the most sensitive and specific biomarker for AD (Tapiola et al., 2009; Hertze et al., 2010; Palmqvist et al., 2016).