Risk factors for delirium occurring after deep brain stimulation surgery in patients with Parkinson's disease.

Objective: Postoperative delirium (POD) may cause cognitive morbidities and prolonged hospital stay. This study aimed to evaluate the risk factors associated with postoperative delirium in patients undergoing deep brain stimulation (DBS) for Parkinson's disease (PD).

Method: We retrospectively reviewed 83 patients with idiopathic PD who underwent bilateral DBS between 2016 and 2023. The target of DBS was the globus pallidus interna (Gpi) or the subthalamic nucleus (STN) in 84.3% and 15.7% of patients, respectively. Patients were evaluated using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and categorized into two groups: those with delirium and those without. Demographic features, disease duration, preoperative cognitive status (Mini-Mental State Examination) and silent ischemia, brain atrophy rates, DBS target location, surgical type and duration, Unified PD Rating Scale-3 scores, Hoehn and Yahr scores, postoperative perilead edema, and electrolyte imbalance were compared between patients with and without post-DBS delirium. Apart from univariate analysis, receiver operating characteristic (ROC) curve analysis for disease duration and multivariate logistic regression analyses were used to determine independent risk factors for post-DBS delirium.

Results: Five out of the 83 patients (6%) developed post-DBS delirium. Age (> 68 years), disease duration, preoperative cerebral atrophy rates, and postoperative perilead edema were significantly higher in patients who developed delirium (p < 0.05 each). The ROC curve analysis revealed disease duration of ≥ 11 years as a risk factor for delirium (p = 0.001; odds ratio, OR: 58.4, 95% confidence interval, CI: 5.45-625.49). Age and disease duration were independent risk factors for post-DBS delirium (OR: 1.243, 95% CI: 1.070-1.592 and OR: 22.52, 95% CI: 1.21-383.96, respectively).

Conclusions: Older age and longer disease duration are independent risk factors for postoperative delirium in patients with PD. This study highlights the need to identify high-risk patients when undertaking DBS to facilitate early diagnosis and timely management.