Early post-deep brain stimulation psychiatric adverse events in Parkinson's disease: a narrative review

Deep brain stimulation (DBS) is a surgical treatment for medication-resistant motor symptoms in Parkinson's disease (PD), involving the implantation of electrodes in subcortical targets, primarily the subthalamic nucleus (STN) and internal globus pallidus (GPi). While DBS is effective for motor control, psychiatric factors significantly impact postoperative quality of life. This narrative review aimed to summarise early (<2 weeks) psychiatric adverse events (AEs) following DBS in PD, addressing the prevalence of these events, their effects on pre-existing psychiatric symptoms and the influence of targeting and DBS parameters on these symptoms. A comprehensive search was performed across multiple databases, identifying 148 relevant studies, among which 55 focused on early psychiatric outcomes. Methodological diversity was noted, with 97% of studies concentrating on bilateral STN DBS. Our findings indicate that early postoperative psychiatric AEs are common, primarily occurring within days postsurgery and often transient. These AEs show improvement with parametric adjustments or the introduction of psychiatric medications. Notably, the role of the STN and GPi extends beyond motor control to emotional regulation, emphasising the importance of monitoring psychiatric outcomes in DBS patients. This review highlights the need for increased awareness and management strategies for early psychiatric complications in the context of DBS therapy, ultimately contributing to enhanced patient care and outcomes in advanced PD stages. Future studies should focus on standardising the evaluation of psychiatric AEs and exploring preventive strategies to minimise their occurrence post-DBS. PROSPERO registration number CRD42020184000.