MAPT and Parkinson disease: PD patients with CSF Aβ42 < 384.6 pg/mL, CSF total tau > 45.0 pg/mL and caudate [123I]FP-CIT uptake < 1.82 had a 65% risk of developing CI, as defined by the neuropsychological tests, at a 36-month follow-up (Fig. 1).