Bin Wu

This paper presents a novel real-time signal processing method for removing local field potential (LFP) artifacts during deep-brain stimulation (DBS). Real-time artifact removal is essential for closed-loop DBS systems, as they rely on real-time, artifact-free LFPs to provide stimulation feedback. Building on previous stimulation-sampling synchronization methods, this work introduces a dynamic template subtraction method that achieves precise and efficient real-time removal of stimulation artifacts. By leveraging stimulation-sampling synchronization, the method enables real-time template alignment and artifact removal through subtraction. It can operate even at low sampling rates, requiring a minimum of twice the stimulation frequency. The artifact templates are dynamically updated to adapt to changes in stimulation artifacts, ensuring robust and accurate performance over time. The method was evaluated through simulations and in vitro and in vivo experiments. Simulation tests validated its theoretical feasibility, while it successfully removed stimulation artifacts in vitro, relative errors in the power spectral density between the recovered and reference LFPs in the examined frequency band (1-150 Hz) were 0.64%, 0.31%, 0.58%, and 0.73% under stimulation at 20, 60, 90, and 130 Hz, respectively. In vivo, the method successfully recorded artifact-free LFPs in real time and supported beta-triggered closed-loop DBS. In an additional in vivo evaluation using a commercial medical device, the method recorded artifact-free LFPs with a sampling rate of 260 Hz (twice the stimulation frequency of 130 Hz). The proposed artifact removal method provides important technical support for realizing lightweight closed-loop DBS systems.

Background: To review the incidence and extent of peri‐electrode edema after DBS and to clarify the effect of postoperative use of steroids on the peri‐electrode edema.Methods: This retrospective cohort study included 250 patients who underwent bilateral subthalamic nucleus (STN) DBS surgery with intact MRI within 1 month after DBS surgery. Patients were divided into steroid and non‐steroid groups, based on postoperative steroids use. The occurrence and extent of peri‐electrode edema were compared between the two groups, and other associated factors were analyzed using univariate and multivariate methods.Results: Peri‐electrode edema >1 cm³ in at least one hemisphere was reported in 215 (86.00%) patients. The mean volume of peri‐electrode edema observed in the steroid group was significantly smaller than in the non‐steroid group (8.09 ± 8.47 cm³ vs 17.10 ± 16.90 cm³, p < 0.001). In the steroid group, 104 (32.91%) of the 316 implanted electrodes present with edema less than 1 cm³, whereas in the non‐steroid group, only 27 (14.67%) of the 184 implanted electrodes present with edema less than 1 cm³ (p < 0.001). Multivariate analysis indicated that lesser peri‐electrode edema was significantly associated with postoperative steroids use and general anesthesia.Conclusions: Peri‐electrode edema is common after DBS surgery, and postoperative steroids use reduces the occurrence and extent of peri‐electrode edema.

Background: Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective method for treating Parkinson’s disease (PD). However, safety of STN-DBS treating PD patients with cardiovascular disease (CVD) comorbidity is rarely focused and reported. The aim of this study is to investigate the efficacy and safety of STN-DBS treating PD patients with CVD comorbidity. Methods: We retrospectively included PD patients with CVD comorbidity who underwent STN-DBS under general anesthesia in our center from January 2019 to January 2021. Patient’s PD symptoms and cardiopulmonary function were evaluated by a multi-disciplinary team (MDT) before surgery. Post-operative clinical outcome and complications were collected until 1-year follow-up. Results: A total of 38 patients (26 men/12 women) of mean body mass index (BMI) 24.36 ± 3.11 kg/m², with different CVD comorbidity were finally speculated in the study. These CVD include mainly hypertension, coronary artery disease, thoracic aortic aneurysm, heart valve replacement, pacemaker implantation, atrial fibrillation, patent foramen ovale, and so on. The mean systolic blood pressure (SBP) of 38 patients at admission day, pre-operation day, and discharge day timepoint was 135.63 ± 18.08 mmHg, 137.66 ± 12.26 mmHg, and 126.87 ± 13.36 mmHg, respectively. This showed that blood pressure was controlled well under stable and normal state. The indicators of myocardial infarction Troponin T (Tn T-T) levels at pre-operation, 1 day and 7 days after operation timepoint were 0.014 ± 0.011 ng/mL, 0.015 ± 0.011 ng/mL, and 0.014 ± 0.008 ng/mL, showing no significant fluctuation (F = 0.038, p = 0.962). STN-DBS improved PD patients’ UPDRS III scores by 51.38% (t = 12.33, p < 0.0001) at 1-year follow-up compared with pre-operative baseline. A total of 11 adverse events were recorded until 1-year follow-up. No obvious cardiovascular complications such as intracranial hematoma or clot-related events occurred within 1 year after surgery except 1 case of hematuria. Conclusions: STN-DBS under general anesthesia is safe and effective for treating PD patients with CVD comorbidity. Our clinical experience and protocol of the MDT offers comprehensive perioperative evaluation for DBS surgery and mitigates bleeding and cardiovascular-associated events in PD patients with CVD comorbidity.

Background: Monitoring the depth of anesthesia by electroencephalogram (EEG) based on the prefrontal cortex is an important means to achieve accurate regulation of anesthesia for subthalamic nucleus (STN) deep brain stimulation (DBS) under general anesthesia in patients with Parkinson’s disease (PD). However, no previous study has conducted an in-depth investigation into this monitoring data. Here, we aimed to analyze the characteristics of prefrontal cortex EEG during DBS with propofol general anesthesia in patients with PD and determine the reference range of parameters derived from the depth of anesthesia monitoring. Additionally, we attempted to explore whether the use of benzodiazepines in the 3 days during hospitalization before surgery impacted the interpretation of the EEG parameters. Materials and Methods: We included the data of 43 patients with PD who received STN DBS treatment and SedLine monitoring during the entire course of general anesthesia with propofol in a single center. Eighteen patients (41.86%) took benzodiazepines during hospitalization. We divided the anesthesia process into three stages: awake state before anesthesia, propofol anesthesia state, and shallow anesthesia state during microelectrode recording (MER). We analyzed the power spectral density (PSD) and derived parameters of the patients’ prefrontal EEG, including the patient state index (PSI), spectral edge frequency (SEF) of the left and right sides, and the suppression ratio. The baseline characteristics, preoperative medication, preoperative frontal lobe image characteristics, preoperative motor and non-motor evaluation, intraoperative vital signs, internal environment and anesthetic information, and postoperative complications are listed. We also compared the groups according to whether they took benzodiazepines before surgery during hospitalization. Results: The average PSI of the awake state, propofol anesthesia state, and MER state were 89.86 ± 6.89, 48.68 ± 12.65, and 62.46 ± 13.08, respectively. The preoperative administration of benzodiazepines did not significantly affect the PSI or SEF, but did reduce the total time of suppression, maximum suppression ratio, and the PSD of beta and gamma during MER. Regarding the occurrence of postoperative delirium and mini-mental state examination (MMSE) scores, there was no significant difference between the two groups (chi-square test, p = 0.48; Mann–Whitney U test, p = 0.30). Conclusion: For the first time, we demonstrate the reference range of the derived parameters of the depth of anesthesia monitoring and the characteristics of the prefrontal EEG of patients with PD in the awake state, propofol anesthesia state, and shallow anesthesia during MER. Taking benzodiazepines in the 3 days during hospitalization before surgery reduces suppression and the PSD of beta and gamma during MER, but does not significantly affect the observation of anesthesiologists on the depth of anesthesia, nor affect the postoperative delirium and MMSE scores.

Introduction. Postoperative delirium can increase cognitive impairment and mortality in patients with Parkinson’s disease. The purpose of this study was to develop and internally validate a clinical prediction model of delirium after deep brain stimulation of the subthalamic nucleus in Parkinson’s disease under general anesthesia. Methods. We conducted a retrospective observational cohort study on the data of 240 patients with Parkinson’s disease who underwent deep brain stimulation of the subthalamic nucleus under general anesthesia. Demographic characteristics, clinical evaluation, imaging data, laboratory data, and surgical anesthesia information were collected. Multivariate logistic regression was used to develop the prediction model for postoperative delirium. Results. A total of 159 patients were included in the cohort, of which 38 (23.90%) had postoperative delirium. Smoking (OR 4.51, 95% CI 1.56–13.02, ) was the most important risk factor; other independent predictors were orthostatic hypotension (OR 3.42, 95% CI 0.90–13.06, ), inhibitors of type-B monoamine oxidase (OR 3.07, 95% CI 1.17–8.04, ), preoperative MRI with silent brain ischemia or infarction (OR 2.36, 95% CI 0.90–6.14, ), Hamilton anxiety scale score (OR 2.12, 95% CI 1.28–3.50, ), and apolipoprotein E level in plasma (OR 1.48, 95% CI 0.95–2.29, ). The area under the receiver operating characteristic curve (AUC) was 0.76 (95% CI 0.66–0.86). A nomogram was established and showed good calibration and clinical predictive capacity. After bootstrap for internal verification, the AUC was 0.74 (95% CI 0.66–0.83). Conclusion. This study provides evidence for the independent inducing factors of delirium after deep brain stimulation of the subthalamic nucleus in Parkinson’s disease under general anesthesia. By predicting the development of delirium, our model may identify high-risk groups that can benefit from early or preventive intervention.

Background: After deep brain stimulation (DBS), hiccups as a complication may lead to extreme fatigue, sleep deprivation, or affected prognosis. Currently, the causes and risk factors of postoperative hiccups are unclear. In this study, we investigated the risk factors for hiccups after DBS of the subthalamic nucleus (STN) for Parkinson’s disease (PD) under general anesthesia. Methods: We retrospectively included patients who underwent STN DBS in the study, and collected data of demographic characteristics, clinical evaluations, and medications. According to the occurrence of hiccups within seven days after operation, the patients were divided into a hiccups group and non-hiccups group. The potentially involved risk factors for postoperative hiccups were statistically analyzed by logistic regression analysis. Results: A total of 191 patients were included in the study, of which 34 (17.80%) had postoperative transient persistent hiccups. Binary univariate logistic regression analysis showed that male, higher body mass index (BMI), smoker, Hoehn and Yahr stage (off), preoperative use of amantadine, hypnotic, Hamilton anxiety scale and Hamilton depression scale scores, and postoperative limited noninfectious peri-electrode edema in deep white matter were suspected risk factors for postoperative hiccups (p < 0.1). In binary multivariate logistic regression analysis, male (compared to female, OR 14.00; 95% CI, 1.74–112.43), postoperative limited noninfectious peri-electrode edema in deep white matter (OR, 7.63; 95% CI, 1.37–42.37), preoperative use of amantadine (OR, 3.64; 95% CI, 1.08–12.28), and higher BMI (OR, 3.50; 95% CI, 1.46–8.36) were independent risk factors for postoperative hiccups. Conclusions: This study is the first report about the risk factors of hiccups after STN DBS under general anesthesia for PD patients. The study suggests that male, higher BMI, preoperative use of amantadine, and postoperative limited noninfectious peri-electrode edema in deep white matter are independent risk factors for postoperative hiccups of STN-DBS for PD patients. Most hiccups after STN-DBS for PD patients were transient and self-limiting.

Human languages are based on syntax, a set of rules which allow an infinite number of meaningful sentences to be constructed from a finite set of words. A theory associated with Chomsky and others holds that syntax is a mind-internal, universal structure independent of semantics. This theory, however, has been challenged by studies of the Chinese language showing that syntax is processed under the semantic umbrella, and is secondary and not independent. Here, using intracranial high-density electrocorticography, we find distinct spatiotemporal patterns of neural activity in the left inferior frontal gyrus that are specifically associated with syntactic and semantic processing of Chinese sentences. These results suggest that syntactic processing may occur before semantic processing. Our findings are consistent with the view that the human brain implements syntactic structures in a manner that is independent of semantics.