VHL and Parkinson disease: On the basis of Dunnett’s post-hoc test comparing data in the patient groups with the HV group, statistically significant differences were found between HV and PAF (p = 0.002), PD+OH (p = 0.017), PD No OH (p = 0.016), MSA-P (p = 0.018), and VHL (p = 0.015).