Anesthesia for deep brain stimulation system implantation: adapted protocol for awake and asleep surgery using microelectrode recordings

Dexmedetomidine for awake craniotomy: Systematic review and meta-analysis

INTRODUCTION

For awake craniotomy, monitored anaesthesia care (MAC) had shown relatively lower failure rates. Nevertheless, the conclusion of the appropriate anaesthetic agents, and complications, has not been proposed. Therefore, the systematic review and meta-analysis was done to compare the clinical profile, surgical outcomes, and anesthesia-related complications between dexmedetomidine-based and non-dexmedetomidine regimens during monitored anesthesia care (MAC) for this procedure.

EVIDENCE ACQUISITION

Published clinical trials described MAC, including the amount of anaesthetic drugs, or the number of patients for awake craniotomy between January 1st, 2009 and March 31st, 2022 were reviewed through PubMed, Scopus, Google Scholar, and grey literature index. The standard methodological procedures were following the PRISMA statement with the PROSPERO registration. Twenty-two articles with 2,137 awake craniotomy patients identified as epilepsy surgery, deep brain stimulation procedure, and intracranial surgery closed to an eloquent area with intraoperative awakening for neuro-evaluation were included. The relative risk (RR) regarding surgical outcomes, and anaesthesia-related complications were compared.

EVIDENCE SYNTHESIS

Dexmedetomidine-based versus non-dexmedetomidine anaesthetic regimen revealed no statistically significant differences in surgical outcomes (RR 1.08, 95 %CI 0.94-1.24), conversion to general anaesthesia (RR 0.45, 95 %CI 0.05-3.83), respiratory complications (RR 0.4, 95 %CI 0.12-1.27), and intraoperative nausea and vomiting (RR 0.30, 95 %CI 0.08-1.14). However, the intraoperative seizure was higher in non-dexmedetomidine group (RR 4.26, 95 %CI 1.49-12.16).

CONCLUSION

MAC for awake craniotomy with dexmedetomidine seems to be effective and safe. Randomized controlled trials with standard protocol in specific group of patients and surgical interventions would further demonstrate a clear benefit of dexmedetomidine in awake craniotomy under MAC.

A Meta-Analysis of Medication Reduction and Motor Outcomes After Awake Versus Asleep Deep Brain Stimulation for Parkinson Disease

BACKGROUND AND OBJECTIVES

There remains significant debate regarding the performance of deep brain stimulation (DBS) procedures for Parkinson disease (PD) under local or general anesthesia. The aim of this meta-analysis was to compare the clinical outcomes between "asleep" DBS (general anesthesia) and "awake" DBS (local anesthesia) for PD.

METHODS

We conducted a comprehensive literature review of all published studies on DBS for PD following PRISMA guideline on PubMed and Cochrane library from January 2004 to April 2023. Inclusion criteria included cohort ≥15 patients, clinical outcomes data which included Unified Parkinson's Disease Rating Scale (UPDRS) score and levodopa equivalent daily dosage (LEDD), and ≥3 months of follow-up. Analysis was conducted using Stata software.

RESULTS

There were 18 articles that met inclusion criteria. On meta-analysis, there were no significant differences between awake or asleep DBS with regard to percent change in UPDRS III "off" med/"on" DBS condition ( P = .6) and LEDD score ( P = .99). On subgroup analysis, we found that the choice of target had no significant effect on improvement of UPDRS III ( P = 1.0) or LEDD ( P = .99) change for the asleep vs awake operative approach. There were also no statistically significant differences between microelectrode recording (MER) use and no MER use in postoperative UPDRS III ( P = 1.0) or LEDD improvement ( P = .90) between awake and asleep surgery.

CONCLUSION

There was no significant difference in the primary motor outcomes and LEDD improvement between asleep vs awake DBS. The variables of target selection and MER use had no statistically significant impact on outcome. We find that asleep techniques are both safe and effective compared with the awake technique.

Intraoperative DBS targeting of the globus pallidus internus by using motor evoked potentials

OBJECTIVES

Target localization for deep brain stimulation (DBS) is a crucial step that influences the clinical benefit of the DBS procedure together with the reduction of side effects. In this work, we address the feasibility of DBS target localization in the globus pallidus internus (GPi) aided by intraoperative motor evoked potentials (MEP) with emphasis on the reduction of capsular side effects.

MATERIAL AND METHODS

Micro-macroelectrode recordings were performed intraoperatively on 20 patients that underwent DBS treatment of the GPi (GPi-DBS). MEP were elicited intraoperatively by microelectrode stimulation during stereotactic DBS surgery. We studied the relationship between MEP thresholds and the internal capsule (IC) proximity.

RESULTS

We found a significant correlation between intraoperative MEP thresholds and IC proximity.

CONCLUSIONS

We provide further evidence of the role of MEPs for DBS target localization in the GPi, which extends and confirms the usefulness of MEPs as previously reported by DBS target localization studies dealing with the subthalamic and thalamic nuclei. Our approach is advantageous in that it provides criteria to determine the DBS target without the need to rely on a patient's response while avoiding capsular effects.

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.

Asleep versus awake GPi DBS surgery for Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Patients with Parkinson's Disease (PD) who receive either asleep image-guided subthalamic nucleus deep brain stimulation (DBS) or the traditional awake technique have comparable motor outcomes. However, there are fewer studies regarding which technique should be chosen for globus pallidus internus (GPi) DBS. This systematic review and meta-analysis aims to compare the accuracy of lead placement and motor outcomes of asleep versus awake GPi DBS PD population.

METHODS

We systematically searched PubMed, Embase, and Cochrane for studies comparing asleep vs. awake GPi DBS lead placement in patients with PD. Outcomes were spatial accuracy of lead placement, measured by radial error between intended and actual location, motor improvement measured using (UPDRS III), and postoperative stimulation parameters. Statistical analysis was performed with Review Manager 5.1.7. and OpenMeta [Analyst].

RESULTS

Three studies met inclusion criteria with a total of 247 patients. Asleep DBS was used to treat 192 (77.7 %) patients. Follow-up ranged from 6 to 48 months. Radial error was not statistically different between groups (MD -0.49 mm; 95 % CI -1.0 to 0.02; I2 = 86 %; p = 0.06), with a tendency for higher target accuracy with the asleep technique. There was no significant difference between groups in change on motor function, as measured by UPDRS III, from pre- to postoperative (MD 8.30 %; 95 % CI -4.78 to 21.37; I2 = 67 %, p = 0.2). There was a significant difference in postoperative stimulation voltage, with the asleep group requiring less voltage than the awake group (MD -0.27 V; 95 % CI -0.46 to - 0.08; I2 = 0 %; p = 0.006).

CONCLUSION

Our meta-analysis indicates that asleep image-guided GPi DBS presents a statistical tendency suggesting superior target accuracy when compared with the awake standard technique. Differences in change in motor function were not statistically significant between groups.

What helps patients to prepare for and cope during awake craniotomy? A prospective qualitative study

There is growing interest in awake craniotomies, but some clinicians are concerned that such procedures are poorly tolerated by patients. Therefore, we conducted a study to assess this phenomenon. In this prospective qualitative study, 68 patients who qualified for awake craniotomy were asked to complete the Hospital Anxiety and Depression Scale (HADS)-two days before the surgery and visual analogue scales (VAS) for pain and stress, two days before the surgery and again about two days after. In addition, after their surgery, they took part in a structured interview about what helped them prepare for and cope with the surgery. Most patients tolerated the awake surgery well, scoring low on stress and pain scales. They reported a lower level of stress during the surgery (when questioned afterwards) than before it. Intensity of stress before the surgery correlated negatively with age, positively with HADS anxiety score and positively with stress subsequently experienced during surgery. The level of stress during surgery was associated with stress experienced before the surgery, pain and HADS anxiety and depression scores. Severity of pain during the surgery was positively correlated with stress during surgery and HADS depression and anxiety scores before the surgery. There was no correlation between stress, pain, anxiety and depression and the location of the lesion. Patients have a high tolerance for awake craniotomy. Various factors have an impact on how well patients cope with the operation. Extensive preoperative preparation should be considered a key part of the procedure.

EEG Changes during Propofol Anesthesia Induction in Vegetative State Patients Undergoing Spinal Cord Stimulation Implantation Surgery

OBJECTIVE

To compare the EEG changes in vegetative state (VS) patients and non-craniotomy, non-vegetative state (NVS) patients during general anesthesia with low-dose propofol and to find whether it affects the arousal rate of VS patients.

METHODS

Seven vegetative state patients (VS group: five with traumatic brain injury, two with ischemic-hypoxic VS) and five non-craniotomy, non-vegetative state patients (NVS group) treated in the Department of Neurosurgery, Peking University International Hospital from January to May 2022 were selected. All patients were induced with 0.5 mg/kg propofol, and the Bispectral Index (BIS) changes within 5 min after administration were observed. Raw EEG signals and perioperative EEG signals were collected and analyzed using EEGLAB in the MATLAB software environment, time-frequency spectrums were calculated, and EEG changes were analyzed using power spectrums.

RESULTS

There was no significant difference in the general data before surgery between the two groups (p > 0.05); the BIS reduction in the VS group was significantly greater than that in the NVS group at 1 min, 2 min, 3 min, 4 min, and 5 min after 0.5 mg/kg propofol induction (p < 0.05). Time-frequency spectrum analysis showed the following: prominent α band energy around 10 Hz and decreased high-frequency energy in the NVS group, decreased high-frequency energy and main energy concentrated below 10 Hz in traumatic brain injury VS patients, higher energy in the 10-20 Hz band in ischemic-hypoxic VS patients. The power spectrum showed that the brain electrical energy of the NVS group was weakened R5 min after anesthesia induction compared with 5 min before induction, mainly concentrated in the small wave peak after 10 Hz, i.e., the α band peak; the energy of traumatic brain injury VS patients was weakened after anesthesia induction, but no α band peak appeared; and in ischemic-hypoxic VS patients, there was no significant change in low-frequency energy after anesthesia induction, high-frequency energy was significantly weakened, and a clear α band peak appeared slightly after 10 Hz. Three months after the operation, follow-up visits were made to the VS group patients who had undergone SCS surgery. One patient with traumatic brain injury VS was diagnosed with MCS-, one patient with ischemic-hypoxic VS had increased their CRS-R score by 1 point, and the remaining five patients had no change in their CRS scores.

CONCLUSIONS

Low doses of propofol cause great differences in the EEG of different types of VS patients, which may be the unique response of damaged nerve cell residual function to propofol, and these weak responses may also be the basis of brain recovery.

Rubrospinal activation during asleep subthalamic nucleus deep brain stimulation: a false localizing sign. Illustrative case

BACKGROUND

Deep brain stimulation (DBS) can be a life-changing intervention for patients with Parkinson's disease (PD), but its success is largely dependent on precise lead placement. The subthalamic nucleus (STN) is one of the most common surgical targets of DBS, but the close anatomical and physiological resemblance of the STN to the mediocaudal red nucleus renders these landmarks difficult to distinguish.

OBSERVATIONS

We present an atypical case in which targeted localization of the STN resulted in symptoms pathognomonic of rubrospinal tract (RST) stimulation. A 79-year-old female with a 12-year history of right-hand resting tremor due to medically refractory PD presented for asleep bilateral STN-DBS surgery. Right STN intraoperative testing revealed left hand and elbow flexion contractures, initially suggestive of corticospinal tract activation, despite imaging studies demonstrating reasonable lead placement in the central dorsolateral STN. The lead was moved anteromedially near the medial border of the STN, but stimulation at this location revealed similar but more robust flexor hand and arm contractures, without any extraocular muscle involvement. Thus, activation of the RST was suspected.

LESSONS

Isolated activation of the RST is possible during STN-DBS surgery. Its identification can help avoid false localization and suboptimal lead placement.

The Effects of Different Anesthesia Methods on the Treatment of Parkinson’s Disease by Bilateral Deep Brain Stimulation of the Subthalamic Nucleus

Background

Subthalamic nucleus deep brain stimulation (STN–DBS) surgery for Parkinson’s disease (PD) is routinely performed at medical centers worldwide. However, it is debated whether general anesthesia (GA) or traditional local anesthetic (LA) is superior.

Purpose

This study aims to compare the effects of LA and GA operation methods on clinical improvement in patients with PD, such as motor and non-motor symptoms, after STN–DBS surgery at our center.

Method

A total of 157 patients with PD were retrospectively identified as having undergone surgery under LA (n = 81) or GA (n = 76) states. In this study, the Unified Parkinson’s Disease Rating Scale Motor Score (UPDRS-III) in three states, levodopa-equivalent-daily-dose (LEDD), surgical duration, intraoperative microelectrode recording (iMER) signal length, postoperative intracranial volume, electrode implantation error, neuropsychological function, quality of life scores, and complication rates were collected and compared. All patients with PD were routinely followed up at 6, 12, 18, and 24 months postoperatively.

Result

Overall improvement in UPDRS-III was demonstrated at postoperative follow-up, and there was no significant difference between the two groups in medication-off, stimulation-off state and medication-off, stimulation-on state. However, UPDRS-III scores in medication-on, stimulation-on state under GA was significantly lower than that in the LA group. During postoperative follow-up, LEDD in the LA group (6, 12, 18, and 24 months, postoperatively) was significantly lower than in the GA group. However, there were no significant differences at baseline or 1-month between the two groups. The GA group had a shorter surgical duration, lower intracranial volume, and longer iMER signal length than the LA group. However, there was no significant group difference in electrode implantation accuracy and complication rates. Additionally, the Hamilton Anxiety Scale (HAMA) was significantly lower in the GA group than the LA group at 1-month follow-up, but this difference disappeared at longer follow-up. Besides, there was no significant group difference in the 39-item Parkinson’s Disease Questionnaire (PDQ-39) scale scores.

Conclusion

Although both groups showed overall motor function improvement without a significant postoperative difference, the GA group seemed superior in surgical duration, intracranial volume, and iMER signal length. As the accuracy of electrode implantation can be ensured by iMER monitoring, DBS with GA will become more widely accepted.

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.