MAPT and Parkinson disease: In this study, T-tau level in CSF from the PD-NPSs group was significantly higher than that from the PD-nNPSs group (Table 5), and NPI score positively correlated with T-tau level in CSF from patients with PD, in which P-value was near to statistically significant (Table 6), indicating that neurodegeneration in the PD-NPSs group was more remarkable than that in the PD-nNPSs.