According to current guidelines, lumbar puncture and CSF analyses are indicated only for complicated dementia cases; in these cases, based on their maximum YI index, we recommend the following cutoff values for the five measured biomarkers: Aβ42 < 570.9 pg/mL, t-tau > 241.6 pg/mL, p-tau > 56.49 pg/mL, t-tau/Aβ42 ratio > 0.529, and p-tau/Aβ ratio > 0.08465 (Table 3). Here, MAPT is linked to dementia.