Impact of Subthalamic Nucleus Stimulation on Urinary Dysfunction and Constipation in Parkinson’s Disease

Abstract

Introduction. The effect of subthalamic nucleus deep brain stimulation (STN DBS) on urinary dysfunction and constipation in Parkinsons disease (PD) is variable. This study aims to identify potential surgical and non-surgical variables predicting their outcome. Methods. We used the Movement Disorder Society-Unified PD Rating Scale (MDS-UPDRS) Part I to assess urinary dysfunction (item 10) and constipation (item 11) preoperatively and 6-12 months postoperatively. A multiple linear regression model was used to investigate the impact of Global Cerebral Atrophy (GCA) and active electrode contact location on the urinary dysfunction and constipation follow-up score, controlling for age, disease duration, baseline score, motor improvement, and levodopa-equivalent dose changes. An electric field model was applied to localize the maximal effect-site for constipation and urinary dysfunction compared to motor improvement. Result. Among 74 patients, 23 improved, 28 deteriorated, and 23 remained unchanged for urinary dysfunction; 25 improved, 15 deteriorated, and 34 remained unchanged for constipation. GCA score and age significantly predicted urinary dysfunction follow-up score (R2 = 0.36, P<0.001). Increasing GCA and age independently were associated with worsening urinary symptoms. Disease duration, baseline constipation score, and anterior active electrode contacts in both hemispheres were significant predictors for constipation follow-up score (R2 =0.31, P<0.001). Higher baseline constipation score and disease duration were associated with worsening constipation; anterior active contact location was associated with improvement in constipation. Conclusion. Anterior active contact locations are associated with improvement in constipation in PD patients after STN DBS. PD patients with greater GCA scores before surgery were more likely to experience urinary deterioration after DBS.