Depressive symptoms can negatively influence patient reported disease severity after subthalamic nucleus stimulation...

BackgroundDepression can negatively influence an individual's perception of their disease. Although subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for Parkinson's disease (PD), some patients do not appreciate benefits despite showing objective improvements in motor function.ObjectiveWe explored the impact of depressive symptoms on self-reported outcomes of PD severity in patients who underwent STN-DBS.MethodsAssessments took place preoperatively and 2-years after surgery. Patients completed the Hospital Anxiety and Depression Scale (HADS), Unified Parkinson's Disease Rating Scale (UPDRS) Parts 2 and 4, Gait and Falls Questionnaire, Parkinson's Disease Questionnaire-39 (PDQ-39), and the Non-motor Symptoms Scale. The UPDRS Part 3 (motor examination) was also performed. Patients were dichotomized into two groups (normal or high) based on their postoperative follow-up HADS depression score.ResultsEighteen patients (33.3%) were assigned to the high group (hHADS-D), and 36 patients (66.7%) were assigned to the normal group (nHADS-D). The UPDRS Part 3 OFF-medication score improved to a similar extent in both groups, and participants experienced a similar reduction in their levodopa equivalent daily dose following STN-DBS. Unlike the nHADS-D group, however, hHADS-D patients did not self-report improvements on any clinical outcome measure at follow-up from baseline, and instead indicated a significant worsening on the UPDRS Part 2 ON-medication and PDQ-39 cognition domain. This was not explicable by their preoperative non-motor symptom burden, nor changes in dopaminergic medications. There were no differences between groups in terms of proportion using anti-depressants, surgical complications or postoperative side effects.ConclusionsDepressive symptoms may play a significant role in subjective self-reporting, and should be carefully considered when evaluating STN-DBS effectiveness and managing patients postoperatively.