MAPT and Mental deterioration: Strikingly, amyloid/tau stratification showed that high CSF bisecting GlcNAc levels predicted earlier cognitive decline in amyloid-negative patients (β = 2.53 ± 0.85 years, P = 0.003) and tau-negative patients (β = 2.43 ± 1.01 years, P = 0.017), but not in amyloid- or tau-positive patients.