Anesthesia and Postoperative Delirium in Parkinson DBS

Parkinson's disease (PD) is a chronic progressive neurodegenerative disorder characterized by both motor symptoms (bradykinesia, resting tremor, rigidity, postural instability) and non-motor symptoms, among which cognitive impairment is a prevalent and debilitating complication. Subthalamic nucleus deep brain stimulation (STN-DBS) has been a standard therapy for advanced PD for nearly three decades, with well-established long-term benefits for motor symptom control. However, perioperative cognitive dysfunction remains a major concern: the incidence of postoperative cognitive dysfunction (POCD) in elderly surgical patients ranges from 10% to 54%, and PD patients are inherently at higher baseline risk of cognitive decline due to underlying neurodegeneration.

Anesthetic management is a critical modifiable factor in STN-DBS procedures. Clinically, regional anesthesia with awake sedation is preferred for most PD patients to allow intraoperative neurophysiological monitoring and behavioral assessment; however, a subset of patients cannot tolerate awake surgery due to severe rigidity, tremor, or anxiety, requiring adjusted anesthetic regimens. Notably, anesthetic agents can interfere with microelectrode recording (MER) signals to varying degrees, potentially affecting electrode targeting accuracy, while different anesthetic strategies may also differentially impact postoperative neurocognitive outcomes via mechanisms such as neuroinflammation, oxidative stress, or modulation of beta oscillatory activity in the basal ganglia. To date, no prospective study has systematically evaluated the long-term cognitive trajectory of PD patients after STN-DBS or compared the neurocognitive safety profiles of different anesthesia management protocols in this population.

This prospective cohort study will enroll PD patients scheduled for bilateral STN-DBS and assign them to cohorts based on their clinically determined anesthesia management strategy (regional anesthesia with awake sedation vs. modified sedation/anesthesia regimens for patients intolerant to awake surgery). Beyond the primary outcome of POCD incidence, the study will collect intraoperative MER data (root mean square values of MER signals, beta band power via discrete Fourier transform of sampling windows) to explore potential associations between anesthetic exposure, electrophysiological signal quality, and postoperative cognitive outcomes. All enrolled patients will undergo serial cognitive and non-motor symptom assessments at predefined perioperative timepoints to establish cognitive trajectories, identify anesthetic and non-anesthetic risk factors for POCD via multivariable regression, and provide evidence for personalized anesthesia management in PD patients undergoing DBS.

Inclusion criteria

• Aged 50-80 years old
• American Society of Anesthesiologists (ASA) physical status classification II-III
• Scheduled for bilateral subthalamic nucleus deep brain stimulation (STN-DBS) for Parkinson's disease
• Signed informed consent prior to enrollment

Exclusion criteria

• Obstructive sleep apnea
• Body mass index (BMI) >30 kg/m²
• Predicted difficult airway
• Severe preoperative anxiety
• Severe dysfunction of vital organs (e.g., heart failure, renal or hepatic dysfunction)
• History of allergy to anesthetic agents