Optimized Propofol Anesthesia Increases Power of Subthalamic Neuronal Activity in Patients with Parkinson's Disease Undergoing Deep Brain Stimulation

Intraoperative microelectrode recording during asleep deep brain stimulation of subthalamic nucleus for Parkinson Disease. A case series with systematic review of the literature

The use of microelectrode recording (MER) during deep brain stimulation (DBS) for Parkinson Disease is controversial. Furthermore, in asleep DBS anesthesia can impair the ability to record single-cell electric activity.The purpose of this study was to describe our surgical and anesthesiologic protocol for MER assessment during asleep subthalamic nucleus (STN) DBS and to put our findings in the context of a systematic review of the literature. Sixty-three STN electrodes were implanted in 32 patients under general anesthesia. A frameless technique using O-Arm scanning was adopted in all cases. Total intravenous anesthesia, monitored with bispectral index, was administered using a target controlled infusion of both propofol and remifentanil. A systematic review of the literature with metanalysis on MER in asleep vs awake STN DBS for Parkinson Disease was performed. In our series, MER could be reliably recorded in all cases, impacting profoundly on electrode positioning: the final position was located within 2 mm from the planned target only in 42.9% cases. Depth modification > 2 mm was necessary in 21 cases (33.3%), while in 15 cases (23.8%) a different track was used. At 1-year follow-up we observed a significant reduction in LEDD, UPDRS Part III score off-medications, and UPDRS Part III score on medications, as compared to baseline. The systematic review of the literature yielded 23 papers; adding the cases here reported, overall 1258 asleep DBS cases using MER are described. This technique was safe and effective: metanalysis showed similar, if not better, outcome of asleep vs awake patients operated using MER. MER are a useful and reliable tool during asleep STN DBS, leading to a fine tuning of electrode position in the majority of cases. Collaboration between neurosurgeon, neurophysiologist and neuroanesthesiologist is crucial, since slight modifications of sedation level can impact profoundly on MER reliability.

Anesthetic Effect on the Subthalamic Nucleus in Microelectrode Recording and Local Field Potential of Parkinson's Disease

OBJECTIVES

Anesthetic agents used during deep brain stimulation (DBS) surgery might interfere with microelectrode recording (MER) and local field potential (LFP) and thus affect the accuracy of surgical target localization. This review aimed to identify the effects of different anesthetic agents on neuronal activity of the subthalamic nucleus (STN) during the MER procedure.

MATERIALS AND METHODS

We used Medical Subject Heading terms to search the PubMed, EMBASE, EBSCO, and ScienceDirect data bases. MER characteristics were sorted into quantitative and qualitative data types. Quantitative data included the burst index, pause index, firing rate (FR), and interspike interval. Qualitative data included background activity, burst discharge (BD), and anesthetic agent effect. We also categorized the reviewed manuscripts into those describing local anesthesia with sedation (LAWS) and those describing general anesthesia (GA) and compiled the effects of anesthetic agents on MER and LFP characteristics.

RESULTS

In total, 26 studies on MER were identified, of which 12 used LAWS and 14 used GA. Three studies on LFP also were identified. We found that the FR was preserved under LAWS but tended to be lower under GA, and BD was reduced in both groups. Individually, propofol enhanced BD but was better used for sedation, or the dosage should be minimized in GA. Similarly, low-dose dexmedetomidine sedation did not disturb MER. Opioids could be used as adjunctive anesthetic agents. Volatile anesthesia had the least adverse effect on MER under GA, with minimal alveolar concentration at 0.5. Dexmedetomidine anesthesia did not affect LFP, whereas propofol interfered with the power of LFP.

CONCLUSIONS

The effects of the tested anesthetics on the STN in MER and LFP of Parkinson's disease varied; however, identifying the STN and achieving a good clinical outcome are possible under controlled anesthetic conditions. For patient comfort, anesthesia should be considered in STN-DBS.

Delayed-onset seizures after subthalamic nucleus deep brain stimulation surgery for Parkinson's disease

BACKGROUND

Delayed-onset seizures after deep brain stimulation (DBS) surgery were seldom reported. This study summarized the clinical characteristics of delayed-onset seizures after subthalamic nucleus (STN) DBS surgery for Parkinson's disease (PD) and analyzed risk factors.

METHODS

A single-center retrospective study containing consecutive STN-DBS PD patients from 2006 to 2021 was performed. Seizures occurred during the DBS surgery or within one month after DBS surgery were identified based on routine clinical records. Patients with postoperative magnetic resonance imaging (MRI) were included to further analyze the risk factors for postoperative seizures with univariate and multivariate statistical methods.

RESULTS

341 consecutive PD patients treated with bilateral STN-DBS surgery wereidentified, and five patients experienced seizures after DBS surgery with an incidence of 1.47 %. All seizures of the five cases were characterized as delayed onset with average 12 days post-operatively. All seizures presented as generalized tonic-clonic seizures and didn't recur after the first onset. In those seizures cases, peri-electrode edema was found in both hemispheres without hemorrhage and infarction. The average diameter of peri-electrode edema of patients with seizures was larger than those without seizures (3.15 ± 1.00 cm vs 1.57 ± 1.02 cm, p = 0.005). Multivariate risk factor analysis indicated that seizures were only associated with the diameter of peri-electrode edema (OR 4.144, 95 % CI 1.269-13.530, p = 0.019).

CONCLUSIONS

Delayed-onset seizures after STN-DBS surgery in PD patients were uncommon with an incidence of 1.47 % in this study. The seizures were transient and self-limiting, with no developing into chronic epilepsy. Peri-electrode edema was a risk factor for delayed-onset seizures after DBS surgery. Patients with an average peri-electrode edema diameter > 2.70 cm had a higher risk to develop seizures.

General anesthesia versus local anesthesia for deep brain stimulation targeting of STN in Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Subthalamic nucleus deep brain stimulation (STN-DBS) is a viable therapeutic for advanced Parkinson's disease. However, the efficacy and safety of STN-DBS under local anesthesia (LA) versus general anesthesia (GA) remain controversial. This meta-analysis aims to compare them using an expanded sample size.

METHODS

The databases of Embase, Cochrane Library and Medline were systematically searched for eligible cohort studies published between 1967 and 2023. Clinical efficacy was assessed using either Unified Parkinson's Disease Rating Scale (UPDRS) section III scores or levodopa equivalent dosage requirements. Subgroup analyses were performed to assess complications (adverse effects related to stimulation, general neurological and surgical complications, and hardware-related complications).

RESULTS

Fifteen studies, comprising of 13 retrospective cohort studies and 2 prospective cohort studies, involving a total of 943 patients were included in this meta-analysis. The results indicate that there were no significant differences between the 2 groups with regards to improvement in UPDRS III score or postoperative levodopa equivalent dosage requirement. However, subgroup analysis revealed that patients who underwent GA with intraoperative imaging had higher UPDRS III score improvement compared to those who received LA with microelectrode recording (MER) (P = .03). No significant difference was found in the improvement of UPDRS III scores between the GA group and LA group with MER. Additionally, there were no notable differences in the incidence rates of complications between these 2 groups.

CONCLUSIONS

Our meta-analysis indicates that STN-DBS performed under GA or LA have similar clinical outcomes and complications. Therefore, GA may be a suitable option for patients with severe symptoms who cannot tolerate the procedure under LA. Additionally, the GA group with intraoperative imaging showed better clinical outcomes than the LA group with MER. A more compelling conclusion would require larger prospective cohort studies with a substantial patient population and extended long follow-up to validate.

Awake versus Asleep Anesthesia in Deep Brain Stimulation Surgery for Parkinson's Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

Deep brain stimulation (DBS) is a well-established surgical therapy for patients with Parkinsons' Disease (PD). Traditionally, DBS surgery for PD is performed under local anesthesia, whereby the patient is awake to facilitate intraoperative neurophysiological confirmation of the intended target using microelectrode recordings. General anesthesia allows for improved patient comfort without sacrificing anatomic precision and clinical outcomes.

METHODS

We performed a systemic review and meta-analysis on patients undergoing DBS for PD. Published randomized controlled trials, prospective and retrospective studies, and case series which compared asleep and awake techniques for patients undergoing DBS for PD were included. A total of 19 studies and 1,900 patients were included in the analysis.

RESULTS

We analyzed the (i) clinical effectiveness - postoperative UPDRS III score, levodopa equivalent daily doses and DBS stimulation requirements. (ii) Surgical and anesthesia related complications, number of lead insertions and operative time (iii) patient's quality of life, mood and cognitive measures using PDQ-39, MDRS, and MMSE scores. There was no significant difference in results between the awake and asleep groups, other than for operative time, for which there was significant heterogeneity.

CONCLUSION

With the advent of newer technology, there is likely to have narrowing differences in outcomes between awake or asleep DBS. What would therefore be more important would be to consider the patient's comfort and clinical status as well as the operative team's familiarity with the procedure to ensure seamless transition and care.

Effects of STN-DBS on cognition and mood in young-onset Parkinson's disease: a two-year follow-up

Background

The effects of subthalamic nucleus deep brain stimulation (STN-DBS) on the cognition and mood of patients with PD are still not uniformly concluded, and young-onset Parkinson's disease (YOPD) is even less explored.

Objective

To observe the effectiveness of STN-DBS on the cognition and mood of YOPD patients.

Methods

A total of 27 subjects, with a mean age at onset of 39.48 ± 6.24 and age at surgery for STN-DBS of 48.44 ± 4.85, were followed up preoperatively and for 2 years postoperatively. Using the Unified Parkinson disease rating scale (UPDRS), H&Y(Hoehn and Yahr stage), 39-Item Parkinson's Disease Questionnaire (PDQ-39), Mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA), Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA) to assess motor, cognition, and mood.

Results

At the 2-year follow-up after STN-DBS, YOPD patients showed significant improvements in motor and quality of life (UPDRS III: p < 0.001, PDQ-39: p < 0.001); overall cognition was not significantly different from preoperative (MMSE: p = 0.275, MoCA: p = 0.913), although language function was significantly impaired compared to preoperative (MMSE: p = 0.004, MoCA: p = 0.009); depression and anxiety symptoms also improved significantly (HAMD: p < 0.001, HAMA: p < 0.001) and the depression score correlated significantly with motor (preoperative: r = 0.493, p = 0.009), disease duration (preoperative: r = 0.519, p = 0.006; postoperative: r = 0.406, p = 0.036) and H&Y (preoperative: r = 0.430, p = 0.025; postoperative: r = 0.387, p = 0.046); total anxiety scores were also significantly correlated with motor (preoperative: r = 0.553, p = 0.003; postoperative: r = 0.444, p = 0.020), disease duration (preoperative: r = 0.417, p = 0.031), PDQ-39 (preoperative: r = 0.464, p = 0.015) and H&Y (preoperative: r = 0.440, p = 0.022; postoperative: r = 0.526, p = 0.005).

Conclusion

STN-DBS is a safe and effective treatment for YOPD. The mood improved significantly, and overall cognition was not impaired, were only verbal fluency decreased but did not affect the improvement in quality of life.

β Oscillations of Dorsal STN as a Potential Biomarker in Parkinson's Disease Motor Subtypes: An Exploratory Study

Parkinson's disease (PD) can be divided into postural instability and difficult gait (PIGD) and tremor dominance (TD) subtypes. However, potential neural markers located in the dorsal ventral side of the subthalamic nucleus (STN) for delineating the two subtypes of PIGD and TD have not been demonstrated. Therefore, this study aimed to investigate the spectral characteristics of PD on the dorsal ventral side. The differences in the β oscillation spectrum of the spike signal on the dorsal and ventral sides of the STN during deep brain stimulation (DBS) were investigated in 23 patients with PD, and coherence analysis was performed for both subtypes. Finally, each feature was associated with the Unified Parkinson's Disease Rating Scale (UPDRS). The β power spectral density (PSD) in the dorsal STN was found to be the best predictor of the PD subtype, with 82.6% accuracy. The PSD of dorsal STN β oscillations was greater in the PIGD group than in the TD group (22.17% vs. 18.22%; p < 0.001). Compared with the PIGD group, the TD group showed greater consistency in the β and γ bands. In conclusion, dorsal STN β oscillations could be used as a biomarker to classify PIGD and TD subtypes, guide STN-DBS treatment, and relate to some motor symptoms.

The efficacy and safety of asleep and awake subthalamic deep brain stimulation for Parkinson's disease patients: A 1-year follow-up

Introduction

Traditional DBS is usually conducted under local anesthesia (LA) which is intolerable to some patients, DBS under general anesthesia (GA) was opted to extended surgical indication. This study aimed to compare the efficacy and safety of bilateral subthalamic deep brain stimulation (STN-DBS) for Parkinson's disease (PD) under asleep and awake anesthesia state in 1-year postoperative follow-up.

Methods

Twenty-one PD patients were assigned to asleep group and 25 patients to awake group. Patients received bilateral STN-DBS under different anesthesia state. The PD participants were interviewed and assessed preoperatively and at 1-year postoperative follow-up.

Results

At 1-year follow-up, compared surgical coordinate in two groups, the left-side Y of asleep group showed more posterior than awake group (Y was-2.39 ± 0.23 in asleep group, -1.46 ± 0.22 in awake group, p = 0.007). Compared with preoperative OFF MED state, MDS-UPDRS III scores in OFF MED/OFF STIM state remained unchanged, while in OFF MED/ON STIM state were significantly improved in awake and asleep groups, yet without significant difference. Compared with preoperative ON MED state, MDS-UPDRS III scores in ON MED/OFF STIM, and ON MED/ON STIM state remained unchanged in both groups. In non-motor outcomes, PSQI, HAMD, and HAMA score significantly improved in asleep group compared to awake group at 1-year follow-up (PSQI, HAMD, and HAMA score in 1-year follow-up were 9.81 ± 4.43; 10.00 ± 5.80; 5.71 ± 4.75 in awake group, 6.64 ± 4.14; 5.32 ± 3.78; 3.76 ± 3.87 in asleep group, p = 0.009; 0.008; 0.015, respectively), while there was no significant difference in PDQ-39, NMSS, ESS, PDSS score, and cognitive function. Anesthesia methods was significantly associated with improvement of HAMA and HAMD score (p = 0.029; 0.002, respectively). No difference in LEDD, stimulation parameters and adverse events was observed between two groups.

Discussion

Asleep STN-DBS may be considered a good alternative method for PD patients. It is largely consistent with awake STN-DBS in motor symptoms and safety. Yet, it showed higher improvement in terms of mood and sleep compared to awake group at 1-year follow-up.

Persistent Hiccups after Subthalamic Nucleus Deep Brain Stimulator Implantation for Parkinson's Disease: Case Report and Literature Review

Hiccups are mediated by a reflex arc that consists of afferent, central, and efferent components. The structures involved in the central component have not been fully elucidated, although several brainstem structures have been implicated, including the subthalamic nucleus (STN). Accordingly, Parkinson's disease (PD), a disease defined by the loss of dopaminergic neurons in the STN, has an interesting, although unspecified, relationship to hiccups. Hiccups have been described in association with PD and the use of dopaminergic medications. Interestingly, deep brain stimulation (DBS) of the STN appears to be implicated in the pathogenesis of hiccups as well. There have been sporadic reports of hiccups occurring in conjunction with STN-DBS. We present a case of hiccups occurring after STN-DBS for PD in a 65-year-old man. STN-DBS significantly improved his PD symptoms; however, he developed persistent and daily hiccups. As of writing, 24 months after surgery, the patient experiences hiccups several times per day with no associated gastrointestinal complaints and with significant improvement in his PD symptoms. This report describes the case details and summarizes the existing literature describing hiccups in patients undergoing surgical treatment for PD.

Characteristics of Electroencephalogram in the Prefrontal Cortex during Deep Brain Stimulation of Subthalamic Nucleus in Parkinson's Disease under Propofol General Anesthesia

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.

Subthalamic Nucleus Deep Brain Stimulation Treats Parkinson's Disease Patients with Cardiovascular Disease Comorbidity: A Retrospective Study of a Single Center Experience

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.

Nomogram for Prediction of Postoperative Delirium after Deep Brain Stimulation of Subthalamic Nucleus in Parkinson’s Disease under General Anesthesia

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, $p<0.01$ ) was the most important risk factor; other independent predictors were orthostatic hypotension (OR 3.42, 95% CI 0.90–13.06, $p=0.07$ ), inhibitors of type-B monoamine oxidase (OR 3.07, 95% CI 1.17–8.04, $p=0.02$ ), preoperative MRI with silent brain ischemia or infarction (OR 2.36, 95% CI 0.90–6.14, $p=0.08$ ), Hamilton anxiety scale score (OR 2.12, 95% CI 1.28–3.50, $p<0.01$ ), and apolipoprotein E level in plasma (OR 1.48, 95% CI 0.95–2.29, $p=0.08$ ). 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.

Clinical Study of Intraoperative Microelectrode Recordings during Awake and Asleep Subthalamic Nucleus Deep Brain Stimulation for Parkinson's Disease: A Retrospective Cohort Study

Our objective is to analyze the difference of microelectrode recording (MER) during awake and asleep subthalamic nucleus deep brain stimulation (STN-DBS) for Parkinson’s disease (PD) and the necessity of MER during “Asleep DBS” under general anesthesia (GA). The differences in MER, target accuracy, and prognosis under different anesthesia methods were analyzed. Additionally, the MER length was compared with the postoperative electrode length by electrode reconstruction and measurement. The MER length of two groups was 5.48 ± 1.39 mm in the local anesthesia (LA) group and 4.38 ± 1.43 mm in the GA group, with a statistical significance between the two groups (p < 0.01). The MER length of the LA group was longer than its postoperative electrode length (p < 0.01), however, there was no significant difference between the MER length and postoperative electrode length in the GA group (p = 0.61). There were also no significant differences in the postoperative electrode length, target accuracy, and postoperative primary and secondary outcome scores between the two groups (p > 0.05). These results demonstrate that “Asleep DBS” under GA is comparable to “Awake DBS” under LA. GA has influences on MER during surgery, but typical STN discharges can still be recorded. MER is not an unnecessary surgical procedure.

Risk Factors for Hiccups after Deep Brain Stimulation of Subthalamic Nucleus for Parkinson's Disease

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.

A practical guide to invasive neurophysiology in patients with deep brain stimulation

Deep brain stimulation (DBS) offers the unique opportunity to record human neural population activity as multiunit activity and local field potentials (LFP) directly from the target area in the depth of the brain. This has led to important discoveries through characterization of pathological activity patterns and identification of motor and cognitive correlates of basal ganglia function in patients with movement disorders. These findings have been covered extensively in a large body of literature, but the technical aspects of microelectrode and LFP recordings in DBS patients are rarely reported. This review summarizes the experience from invasive neurophysiology experiments in over 500 DBS cases in the last 20 years in a single centre. It introduces the basics of intraoperative microelectrode recordings, discusses the neurophysiological and technical aspects of LFP signals and gives and outlook on current and next-generation developments - from sensing enabled implantable devices to combined electrocorticography and LFP recordings during adaptive DBS.