MAPT and early-onset autosomal dominant Alzheimer disease: The CSF level of T-tau generally reflects the intensity of axonal and neuronal degeneration occurring in brain, while P-tau181 serves as a more specific marker for Alzheimer’s disease[30] CSF T-tau, P-tau181 and Aβ1-42 are stable over time making these Alzheimer’s biomarkers feasible for monitoring biochemical effects in clinical trials[31].