Radiographic Abnormalities and Their Clinical Significance in Patients with Parkinson’s Disease with Deep Brain Stimulation

Introduction: Preoperative MRI obtained for surgical planning in Parkinson’s disease (PD) patients scheduled to undergo Deep Brain Stimulation (DBS) often reveals incidental radiological abnormalities (RAs). These findings range from degenerative or vascular changes to gross pathologies. The implication of these findings is unknown. We sought to characterize RAs in PD patients who underwent DBS and to assess their effect on clinical outcomes.

Methods: Patients with CPT codes corresponding to DBS implantation from 2010-2022 at our institution were reviewed. RAs were defined based on the official preoperative MRI report as dictated by a neuroradiologist. RAs were grouped into 4 general categories (ischemic changes, atrophy/degenerative changes (ADCs), structural abnormalities, and tumors), and correlated with clinical outcomes (including subjective clinical outcomes, levodopa equivalent dose (LED), and Unified Parkinson's Disease Rating Scale (UPDRS)) at one year and at last available follow-up.

Results: 160 patients were available for analysis, with 135 presenting with ≥1 RA. Of these 135, 69.4% had ischemic vascular changes, 39.4% had ADCs, 16.9% had structural changes, and 1.9% had tumors. Patients with RAs were older and had increased Charlson comorbidity (CCI) indices (median age 67 vs. 58, p< 0.01; median CCI 3 vs 2, p< 0.01) than patients without RAs. However, no differences in preoperative LED or UPDRS were observed between these groups. Post-DBS, no differences in outcomes were observed between patients with RAs and those without RAs for both 1-year and last follow-up timepoints. ADCs were associated with worse subjective clinical outcomes at 1-year and last follow-up (odds ratios of 0.50 and 0.49, both p< 0.01). However, it was not correlated with a decrease in the objective outcome measures.

Conclusion : Most RAs have no significant effect on clinical outcomes in PD patients undergoing DBS. Generalized ADCs may be associated with worsened subjective outcomes and may warrant further discussion with the patient if diagnosed on preoperative MRI.