We aimed to investigate the association between the brain small vessel disease (SVD) burden and the 1-year outcome after the globus pallidus interna (GPi) deep brain stimulation (DBS) in Parkinson’s disease (PD).

Brain SVD presents as white matter hyperintensities (WMH), enlarged perivascular spaces (EPVS), or lacunes on brain MRI. The clinical implication of SVD burden on the motor outcomes after DBS surgery has not been investigated.

We investigated 53 patients with PD who underwent bilateral GPi DBS surgery. Using preoperative brain MRI, we counted the number of EPVS in the basal ganglia on axial T2-weighted images according to the Standards for Reporting Vascular Changes on Neuroimaging criteria, and we rated WMH using Fazekas scale. The motor severity in PD patients was assessed with Unified Parkinson's Disease Rating Scale (UPDRS) part 3 score both before and 1 year after DBS surgery.

The median age of study population was 61.5 (95% confidence interval 55.0-66.0). The preoperative UPDRS part 3 score at medication on state showed a significant positive correlation with Fazekas scale (r=0.36, P=0.008) and EPVS (r=0.46, P=0.001), respectively. However, the preoperative UPDRS part 3 score at medication off state was not correlated with both Fazekas scale and EPVS (P>0.05). The postoperative UPDRS part 3 score at both medication and stimulation on state showed a positive correlation with EPVS (r=0.32, P=0.02) and a correlation trend with Fazekas scale (r=0.25, P=0.07). The changes in UPDRS part 3 score between before and after DBS surgery did not show the association with Fazekas scale and EPVS at medication-off/stimulation-on state (P>0.05).

This study suggests that the therapeutic effect of DBS in PD patients was not affected by the degree of the brain SVD burden, implicating the outcome prediction of the motor symptoms in PD patients after DBS surgery.