Post hoc tests revealed that the serum p75NTR-ECD level in the AD group (49.14±24.53 pg ml−1) was significantly higher than that in the EC (29.36±20.21 pg ml−1), PD (33.36±11.35 pg ml−1) and stroke (35.17±25.39 pg ml−1) groups. Here, NGFR is linked to Parkinson disease.