Background Parkinsonian disorders and cerebral small vessel disease (CSVD) both become more common with advancing age. Whether the degree of CSVD is greater in parkinsonian patients than nonparkinsonian controls is unclear, as is its role in the presentation and prognosis of parkinsonian disorders.

Methods Baseline MRIs in incident patients with Parkinson's disease (PD) (n=20), vascular parkinsonism (VP) (n=7) and age-sex matched controls (n=21) were scored for CSVD, blinded to clinical status, using Scheltens' visual rating scale. Scheltens' scores were correlated with baseline and follow-up assessments of motor impairment, cognition, mood and functional disability in patients with PD.

Results Total Scheltens' scores were significantly greater in patients with VP than PD or controls (p=0.011), with no difference between the latter two groups. Subgroup analyses showed white matter hyperintensities (WMH), infratentorial hyperintensities (ITF) and periventricular hyperintensities (PVH), but not grey matter hyperintensities (GMH), to be greater in patients with VP than PD or controls. In patients with PD no significant associations between CSVD and baseline or 1-year clinical assessments were found but the latter were confounded by treatment effects.

Conclusions As expected the degree of CSVD was greater in VP patients than PD patients or controls. Additionally, CSVD in PD patients did not significantly affect either the clinical presentation or prognosis at 1 year.