MAPT and Alzheimer disease: The concentrations of CSF t-tau, and p-tau were significantly lower in iNPH patients compared to AD (SMD = −1.26, 95% CI −1.95 to −0.57, P = 0.0004; SMD = −1.54, 95% CI −2.34 to −0.74, P = 0.0002, respectively) and lower than healthy controls (SMD = −0.80, 95% CI −1.50 to −0.09, P = 0.03; SMD = −1.12, 95% CI −1.38 to −0.86, P < 0.00001, respectively).