MAPT and Cognitive impairment: In search for cerebrospinal fluid (CSF) biomarkers of cognitive impairment, CSF total α-synuclein (t-α-syn), amyloid-β42 (Aβ42), total tau (t-tau), and tau phosphorylated at threonine 181 (p-tau) have been extensively studied in different cohorts [7,10,11,12].