Delirium after deep brain stimulation for Parkinson's disease: a meta-analysis of incidence and risk factors

Deep brain stimulation (DBS) is a valuable treatment for Parkinson's disease (PD), but postoperative delirium (POD) is a common complication. Understanding the risk factors for POD is crucial for optimizing patient selection and developing preventative measures. This systematic review and meta-analysis aims to identify predictors of POD in PD patients undergoing DBS surgery. We conducted a comprehensive search of four major databases for cohort studies on POD in patients undergoing DBS for PD, up to June 2024. Two reviewers independently screened studies, assessed the risk of bias using the Newcastle-Ottawa Scale, and extracted data. Meta-analysis was conducted using Review Manager, with heterogeneity assessed the I² statistic and chi-square p value. Subgroup and sensitivity analyses were also performed to explore the consistency of findings. Eleven studies, including 1,368 patients, were analyzed to determine the incidence of POD in PD patients undergoing DBS. The incidence of POD in PD patients undergoing DBS, which was found to be 21% (95% CI: [14.6%, 27.4%]). Age, Mini-Mental State Examination (MMSE), and Non-Motor Symptom Scale (NMSS) were significant predictors, with effect sizes of (OR = 1.10, 95% CI: [1.06, 1.15], P < 0.00001), (OR = 0.85, 95% CI: [0.72, 1.00], P = 0.05), and (OR = 1.01, 95% CI: [1.00, 1.02], P = 0.04), respectively. However, gender, UPDRS-III ON score, brain atrophy, diabetes, Hamilton Anxiety Score (HAMA), operation time, disease duration, BMI, and cerebral infarction were not significant predictors. This meta-analysis suggests that age, cognitive function, and non-motor symptoms are important factors associated with POD patients undergoing DBS surgery. Further research with larger sample sizes and diverse populations is needed to confirm these findings and identify more specific predictors.