Practice guidelines for the supervising professional: intraoperative neurophysiological monitoring

Pediatric Intraoperative Neurophysiological Monitoring and Long-Term Outcomes in a Developing Country

PURPOSE

Pediatric intraoperative neurophysiological monitoring (IONM) has been shown to be effective in preventing and reversing postoperative neurological deficits in developed countries. There are currently no published studies from developing countries that describe neurophysiological findings and postoperative outcomes. Our study aims to address these gaps in children undergoing neurosurgical procedures in a single center.

METHODS

We conducted a retrospective study of case series of children who underwent IONM (2014-2020) in the State of Mexico, Mexico. Sociodemographic characteristics, IONM modalities, changes during procedures, and short-term and long-term postoperative results were recorded. Descriptive statistics were used.

RESULTS

We included 35 patients (≤18 years of age), 57% (20/35) boys. A relative increase of up to 5 times in the use of IONM is observed from 2014 (5.7%) to 2020 (25.7%) in our center. The most frequent preoperative pathologies were located at the infratentorial cranium (40%), followed by the spine and spinal cord (37.1%). The IONM modalities were as follows: free-running EMG 94.3%, transcranial electrical stimulation motor-evoked potentials 91.4%, somatosensory-evoked potentials 85.7%, triggered EMG 28.6%, EEG 25.7%, and visual-evoked potentials 5.7%. Only in 8.3%, we did not obtain sufficient evoked potential baseline signals. At 24 hours postoperatively true negatives were 100%. Long-term follow-up was completed in 22/35 (63%) at 3 months, 12/35 (34.2%) at 6 months, and 5/35 (14.3%) at 12 months with progressive motor and sensory improvement.

CONCLUSIONS

Pediatric multimodal IONM in neurosurgeries from a single center in a developing country is mainly used in pathologies of the posterior fossa, spine, and spinal cord, with true negatives in 100% of those monitored, preventing and avoiding postoperative sequelae.

Intraoperative somatosensory evoked potential (SEP) monitoring: an updated position statement by the American Society of Neurophysiological Monitoring

Somatosensory evoked potentials (SEPs) are used to assess the functional status of somatosensory pathways during surgical procedures and can help protect patients' neurological integrity intraoperatively. This is a position statement on intraoperative SEP monitoring from the American Society of Neurophysiological Monitoring (ASNM) and updates prior ASNM position statements on SEPs from the years 2005 and 2010. This position statement is endorsed by ASNM and serves as an educational service to the neurophysiological community on the recommended use of SEPs as a neurophysiological monitoring tool. It presents the rationale for SEP utilization and its clinical applications. It also covers the relevant anatomy, technical methodology for setup and signal acquisition, signal interpretation, anesthesia and physiological considerations, and documentation and credentialing requirements to optimize SEP monitoring to aid in protecting the nervous system during surgery.

There's No "I" in "Team": Recommendations for Effective Teamwork and Communication in IONM

Effective teamwork is essential in almost every job, and can even mean life, death, or disability in some jobs. Intraoperative neurophysiological monitoring (IONM) is a career in which effective teamwork and accurate communication are of utmost importance, yet it comes with a unique set of challenges in which to achieve those goals. Operating rooms can be very stressful environments, even if a surgical neurophysiologist (SNP) works in the same hospital every day. Often an SNP is required to travel from hospital to hospital and work with different teams each day. In addition, communication with the IONM oversight professional (IONM-P) can be challenging by nature of the telemedicine model which is becoming the most commonly applied IONM model in the United States. It is unfortunate that such critical skills are assumed and are rarely formally trained. In this article, we present evidence-based recommendations for establishing effective team function. We also provide several tools designed to help create effective and efficient teams. Teams cannot function at their best without outstanding communication, so improving teamwork also means improving communication. This article also provides several techniques for excellent communication, regardless of the situation or context.

The "state of the art" of intraoperative neurophysiological monitoring: An Italian neurosurgical survey

Introduction

Intraoperative Neurophysiological Monitoring (IOM) is widely used in neurosurgery but specific guidelines are lacking. Therefore, we can assume differences in IOM application between Neurosurgical centers.

Research question

The section of Functional Neurosurgery of the Italian Society of Neurosurgery realized a survey aiming to obtain general data on the current practice of IOM in Italy.

Materials and methods

A 22-item questionnaire was designed focusing on: volume procedures, indications, awake surgery, experience, organization and equipe. The questionnaire has been sent to Italian Neurosurgery centers.

Results

A total of 54 centers completed the survey. The annual volume of surgeries range from 300 to 2000, and IOM is used in 10-20% of the procedures. In 46% of the cases is a neurologist or a neurophysiologist who performs IOM. For supra-tentorial pathology, almost all perform MEPs (94%) SSEPs (89%), direct cortical stimulation (85%). All centers perform IOM in spinal surgery and 95% in posterior fossa surgery. Among the 50% that perform peripheral nerve surgery, all use IOM. Awake surgery is performed by 70% of centers. The neurosurgeon is the only responsible for IOM in 35% of centers. In 83% of cases IOM implementation is adequate to the request.

Discussion and conclusions

The Italian Neurosurgical centers perform IOM with high level of specialization, but differences exist in organization, techniques, and expertise. Our survey provides a snapshot of the state of the art in Italy and it could be a starting point to implement a consensus on the practice of IOM.

Application value of intraoperative electrophysiological monitoring in cerebral eloquent area glioma surgery: a retrospective cohort study

INTRODUCTION

Surgery for gliomas involving eloquent areas is a very challenging microsurgical procedure. Maximizing both the extent of resection (EOR) and preservation of neurological function have always been the focus of attention. Intraoperative neurophysiological monitoring (IONM) is widely used in this kind of surgery. The purpose of this study was to evaluate the efficacy of IONM in eloquent area glioma surgery.

METHODS

Sixty-eight glioma patients who underwent surgical treatment from 2014 to 2019 were included in this retrospective cohort study, which focused on eloquent areas. Clinical indicators and IONM data were analysed preoperatively, two weeks after surgery, and at the final follow-up. Logistic regression, Cox regression, and Kaplan‒Meier analyses were performed, and nomograms were then established for predicting prognosis. The diagnostic value of the IONM indicator was evaluated by the receiver operating characteristic (ROC) curve.

RESULTS

IONM had no effect on the postoperative outcomes, including EOR, intraoperative bleeding volume, duration of surgery, length of hospital stay, and neurological function status. However, at the three-month follow-up, the percentage of patients who had deteriorated function in the monitored group was significantly lower than that in the unmonitored group (23.3% vs. 52.6%; P < 0.05). Logistic regression analysis showed that IONM was a significant factor in long-term neurological function (OR = 0.23, 95% CI (0.07-0.70). In the survival analysis, long-term neurological deterioration indicated worsened overall survival (OS) and progression-free survival (PFS). A prognostic nomogram was established through Cox regression model analysis, which could predict the probability 3-year survival rate. The concordance index was 0.761 (95% CI 0.734-0.788). The sensitivity and specificity of IONM evoked potential (SSEP and TCeMEP) were 0.875 and 0.909, respectively. In the ROC curve analysis, the area under the curve (AUC) for the SSEP and TCeMEP curves was 0.892 (P < 0.05).

CONCLUSIONS

The application of IONM could improve long-term neurological function, which is closely related to prognosis and can be used as an independent prognostic factor. IONM is practical and widely available for predicting postoperative functional deficits in patients with eloquent area glioma.

Intraoperative neurophysiological monitoring and spinal cord stimulator implantation

INTRODUCTION

Spinal cord injury (SCI) is one of the most dreaded complications after spinal cord stimulation (SCS) implantation surgery. As a result, intraoperative neurophysiological monitoring (IONM) has been proposed to avoid accidental damage to nervous structures under anesthesia and confirm positioning for optimal stimulation. Our study uses a large administrative claims database to determine the 30-day risk of SCI after SCS implantation.

METHODS

This retrospective cohort study used the IBM MarketScan Commercial and Medicare Supplemental Databases from 2016 to 2019. Adult patients undergoing SCS surgical procedures with at least 90 days of follow-up, IONM use, the type of sedation used during the procedure, and subsequent SCI were identified using administrative codes. In addition, logistic regression was used to examine the relationship between various risk factors and subsequent SCI.

RESULTS

A total of 9676 patients underwent SCS surgery (64.7% percutaneous implants) during the study period. Nine hundred and forty-four (9.75%) patients underwent SCS implantation with IONM. Conscious sedation, Monitored Anesthesia Care anesthesia, and general anesthesia were used in patients with 0.9%, 60.2%, and 28.6%, respectively. Eighty-one (0.8%) patients developed SCI within 30 days after SCS implant surgery. The SCI rate was higher in the group that underwent IONM (2% vs 0.7%, p value <0.001) during the implantation procedure, reflecting the underlying risk. After adjustment for other factors, the OR of SCI is 2.39 (95% CI: 1.33 to 4.14, p value=0.002) times higher for those with IONM than those without IONM.

CONCLUSIONS

Increased SCI risk among patients with IONM likely reflects higher baseline risk, and further research is needed for risk mitigation.

In-House Intraoperative Monitoring in Neurosurgery in England - Benefits and Challenges

BACKGROUND

Intraoperative neurophysiological monitoring (IOM) is a valuable adjunct for neurosurgical operative techniques, and has been shown to improve clinical outcomes in cranial and spinal surgery. It is not necessarily provided by NHS hospitals so may be outsourced to private companies, which are expensive and at cost to the NHS trusts. We discuss the benefits and challenges of developing an in-house service.

METHODS

We surveyed NHS neurosurgical departments across England regarding their expenditure on IOM over the period January 2018 - December 2022 on cranial neurosurgery and spinal surgery. Out of 24 units, all responded to our Freedom of Information requests and 21 provided data. The standard NHS England salary of NHS staff who would normally be involved in IOM, including physiologists and doctors, was also compiled for comparison.

RESULTS

The total spend on outsourced IOM, across the units who responded, was over £8 million in total for the four years. The annual total increased, between 2018 and 2022, from £1.1 to £3.5 million. The highest single unit yearly spend was £568,462. This is in addition to salaries for staff in neurophysiology departments. The mean NHS salaries for staff is also presented.

CONCLUSION

IOM is valuable in surgical decision-making, planning, and technique, having been shown to lead to fewer patient complications and shorter length of stay. Current demand for IOM outstrips the internal NHS provision in many trusts across England, leading to outsourcing to private companies. This is at significant cost to the NHS. Although there is a learning curve, there are many benefits to in-house provision, such as stable working relationships, consistent methods, training of the future IOM workforce, and reduced long-term costs, which planned expansion of NHS services may provide.

Intraoperative monitoring of the central and peripheral nervous systems: a narrative review

The central and peripheral nervous systems are the primary target organs during anaesthesia. At the time of the inception of the British Journal of Anaesthesia, monitoring of the central nervous system comprised clinical observation, which provided only limited information. During the 100 yr since then, and particularly in the past few decades, significant progress has been made, providing anaesthetists with tools to obtain real-time assessments of cerebral neurophysiology during surgical procedures. In this narrative review article, we discuss the rationale and uses of electroencephalography, evoked potentials, near-infrared spectroscopy, and transcranial Doppler ultrasonography for intraoperative monitoring of the central and peripheral nervous systems.

New frontiers in intraoperative neurophysiologic monitoring: a narrative review

Background and Objective

Neurological insults during surgery arise from anatomic and/or physiologic perturbations. Intraoperative neurophysiologic monitoring (IONM) fills a critical role of ensuring that any neurological insults during certain surgical procedures are caught in real-time to prevent patient harm. IONM provides immediate feedback to the surgeon and anesthesiologist about the need for an intervention to prevent a neurologic deficit postoperatively. As important as it seems to have IONM available to any patient having surgery where a neurological injury is possible, the truth is that IONM is unavailable to large swaths of people around the world. This review is intended to bring attention to all of the ways IONM is critically important for a variety of surgeries and highlight the barriers preventing most patients around the world from benefiting from the technology. Expansion of IONM to benefit patients from all over the world is the new frontier.

Methods

We searched all English language original papers and reviews using Embase and MEDLINE/PubMed databases published from 1995 to 2022. Different combinations of the following search terms were used: intraoperative neuromonitoring, neurosurgery, low-income countries, cost, safety, and efficacy.

Key Content and Findings

We describe common IONM modalities used during surgery as well as explore barriers to implementation of IONM in resource-limited regions. Additionally, we describe ongoing efforts to establish IONM capabilities in new locations around the world.

Conclusions

In this paper, we performed a review of the literature on IONM with an emphasis on the basic understanding of clinical applications and the barriers for expansion into resource-limited settings. Finally, we provide our interpretation of "new frontiers" in IONM quite literally facilitating access to the tools and education so a hospital in Sub-Saharan Africa can incorporate IONM for their high-risk surgeries.

Application of intraoperative evoked potential monitoring in patients with anterior cerebral artery aneurysms

OBJECTIVES

The location of the aneurysm can affect the relationship between changes in intraoperative neurophysiological monitoring indicators and postoperative outcomes. The current study aimed to evaluate the application value of motor evoked potential and somatosensory evoked potential monitoring in anterior cerebral artery aneurysm surgery.

METHODS

The data of 219 patients with anterior cerebral artery aneurysms treated via surgical clipping were retrospectively reviewed. The correlation of motor/somatosensory evoked potential monitoring with postoperative motor dysfunction was assessed using false positive rate, false negative rate, sensitivity, and specificity. Binary multivariate logistic regression analysis was applied to identify potential predictors for postoperative motor dysfunction.

RESULTS

Motor evoked potential monitoring showed satisfactory effectiveness in predicting postoperative motor dysfunction (Sensitivity, 60.00%; Specificity, 85.43%; False positive rate, 14.57%; False negative rate, 40%). While somatosensory evoked potential did not (Sensitivity, 15.00%; Specificity, 96.98%; False positive rate, 3.02%; False negative rate, 85%). Abnormal motor evoked potential was identified as the only independent predictor for both short-term (odds ratio, 8.893; 95% confidence interval, 2.749-28.773; p<0.001) and long-term postoperative motor dysfunction (odds ratio, 7.877; 95% confidence interval, 2.144-28.945; p=0.002).

CONCLUSIONS

During intraoperative neurophysiological monitoring for patients with anterior cerebral artery aneurysms, paying more attention to motor evoked potential changes was a reasonable choice. And somatosensory evoked potential monitoring can serve as an auxiliary reference.

Coordination of Intraoperative Neurophysiologic Monitoring Technologist and Surgery Schedules

Resource coordination in surgical scheduling remains challenging in health care delivery systems. This is especially the case in highly-specialized settings such as coordinating Intraoperative Neurophysiologic Monitoring (IONM) resources. Inefficient coordination yields higher costs, limited access to care, and creates constraints to surgical quality and outcomes. To maximize utilization of IONM resources, optimization-based algorithms are proposed to effectively schedule IONM surgical cases and technologists and evaluate staffing needs. Data with 10 days of case volumes, their surgery durations, and technologist staffing was used to demonstrate method effectiveness. An iterative optimization-based model that determines both optimal surgery and technologist start time (operational scenario 4) was built in an Excel spreadsheet along with Excel's Solver settings. It was compared with current practice (operational scenario 1) and optimization solution on only surgery start time (operational scenario 2) or technologist start time (operational scenario 3). Comparisons are made with respect to technologist overtime and under-utilization time. The results conclude that scenario 4 significantly reduces overtime by 74% and under-utilization time by 86% as well as technologist needs by 10%. For practices that do not have flexibility to alter surgeon preference on surgery start time or IONM technologist staffing levels, both scenarios 2 and 3 also result in substantial reductions in technologist overtime and under-utilization. Moreover, IONM technologist staffing options are discussed to accommodate technologist preferences and set constraints for surgical case scheduling. All optimization-based approaches presented in this paper are able to improve utilization of IONM resources and ultimately improve the coordination and efficiency of highly-specialized resources.

ASNM and ASN joint guidelines for transcranial Doppler ultrasonic monitoring: An update

Today, it seems prudent to reconsider how ultrasound technology can be used for providing intraoperative neurophysiologic monitoring that will result in better patient outcomes and decreased length and cost of hospitalization. An extensive and rapidly growing literature suggests that the essential hemodynamic information provided by transcranial Doppler (TCD) ultrasonography neuromonitoring (TCDNM) would provide effective monitoring modality for improving outcomes after different types of vascular, neurosurgical, orthopedic, cardiovascular, and cardiothoracic surgeries and some endovascular interventional or diagnostic procedures, like cardiac catheterization or cerebral angiography. Understanding, avoiding, and preventing peri- or postoperative complications, including neurological deficits following abovementioned surgeries, endovascular intervention, or diagnostic procedures, represents an area of great public and economic benefit for society, especially considering the aging population. The American Society of Neurophysiologic Monitoring and American Society of Neuroimaging Guidelines Committees formed a joint task force and developed updated guidelines to assist in the use of TCDNM in the surgical and intensive care settings. Specifically, these guidelines define (1) the objectives of TCD monitoring; (2) the responsibilities and behaviors of the neurosonographer during monitoring; (3) instrumentation and acquisition parameters; (4) safety considerations; (5) contemporary rationale for TCDNM; (6) TCDNM perspectives; and (7) major recommendations.

Motor Mapping of the Brain: Taniguchi Versus Penfield Method

Intraoperative neurophysiological monitoring (IONM) techniques continue to prove useful as an adjunct in select surgeries for reducing the incidence of various postoperative deficits in motor function through the monitoring of motor evoked potentials (MEPs). The Penfield and Taniguchi methods of direct electrical cortical stimulation (DECS) stand in contrast to each other. Penfield’s method uses lower-frequency stimulation over a longer duration, while Taniguchi’s method uses a relatively higher frequency over a short duration. DECS motor mapping is considered suitable for tumor resections, aneurysm surgeries, arteriovenous malformation, and epilepsy surgeries. While subcortical motor mapping works efficiently with both methods, it aligns with Taniguchi’s method more effectively. Taniguchi’s method has a lower risk of seizures relative to Penfield’s method. While only cortical neurons are excited in Penfield’s stimulation technique, Taniguchi’s technique excites the whole corticospinal tract (CST), so it can be used for mapping in a stand-alone fashion. The Penfield technique remains the method of choice for language mapping. In all motor mapping, Train-of-Four (TOF) stimulation during the surgical procedure ensures that the patient’s muscles are not unduly relaxed.

Diagnostic Accuracy of SSEP Changes During Lumbar Spine Surgery for Predicting Postoperative Neurological Deficit: A Systematic Review and Meta-Analysis

STUDY DESIGN

This study is a meta-analysis of prospective and retrospective studies identified in PubMed, Web of Science, and Embase with outcomes of patients who received intraoperative somatosensory-evoked potential (SSEP) monitoring during lumbar spine surgery.

OBJECTIVE

The objective of this study is to determine the diagnostic accuracy of intraoperative lower extremity SSEP changes for predicting postoperative neurological deficit. As a secondary analysis, we evaluated three subtypes of intraoperative SSEP changes: reversible, irreversible, and total signal loss.

SUMMARY OF BACKGROUND DATA

Lumbar decompression and fusion surgery can treat lumbar spinal stenosis and spondylolisthesis but carry a risk for nerve root injury. Published neurophysiological monitoring guidelines provide no conclusive evidence for the clinical utility of intraoperative SSEP monitoring during lumbar spine surgery.

METHODS

A systematic review was conducted to identify studies with outcomes of patients who underwent lumbar spine surgeries with intraoperative SSEP monitoring. The sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated and presented with forest plots and a summary receiver operating characteristic curve.

RESULTS

The study cohort consisted of 5607 patients. All significant intraoperative SSEP changes had a sensitivity of 44% and specificity of 97% with a DOR of 22.13 (95% CI, 11.30-43.34). Reversible and irreversible SSEP changes had sensitivities of 28% and 33% and specificities of 97% and 97%, respectively. The DORs for reversible and irreversible SSEP changes were 13.93 (95% CI, 4.60-40.44) and 57.84 (95% CI, 15.95-209.84), respectively. Total loss of SSEPs had a sensitivity of 9% and specificity of 99% with a DOR of 23.91 (95% CI, 7.18-79.65).

CONCLUSION

SSEP changes during lumbar spine surgery are highly specific but moderately sensitive for new postoperative neurological deficits. Patients who had postoperative neurological deficit were 22 times more likely to have exhibited intraoperative SSEP changes.Level of Evidence: 2.

Emerging Super-specialty of Neurology: Intraoperative Neurophysiological Monitoring (IONM) and Experience in Various Neurosurgeries at a Tertiary Care Hospital in Doha, Qatar

Introduction

Intraoperative neurophysiological monitoring (IONM) helps in better patient outcomes by minimizing risks related to the functional status of the nervous system during surgical procedures. An IONM alert to the surgical team during the surgery can help them identify the cause and take immediate corrective action. IONM confers possible benefits, including improved surgical morbidity and mortality, better patient care, minimal neurological deficits, reduced hospital stay, medical costs, and litigation risk. In addition, a highly skilled IONM team will make a better patient outcome.

Methods

We retrospectively reviewed 62 consecutive patients who underwent intracranial and spinal neurosurgical procedures. Multimodality IONM was utilized, including somatosensory evoked potentials, transcranial electrical motor evoked potential, spontaneous and triggered electromyography, electroencephalography, electrocorticography, cortical sensory mapping, and direct electrical cortical stimulation. Of a total of 62 patients, two patients revealed neurotonic EMG discharges during IONM, and most patients woke up without any new neurological deficit.

Results

Sixty-two patients were included, ranging from age 5 to 77 years (mean 43.5 years), with 54.8% men and 45.2% female. Multimodality IONM was used in all patients. Two EMG alerts were recorded during IONM, during a brain tumor resection, and right acetabular hip surgery with postoperative right foot drop.

Conclusion

Multimodality IONM is the gold standard of care for any surgical services and is used as real-time monitoring of functional integrity of neural structures at risk. If utilized by trained and expert teams, numerous surgeries may benefit from multimodality intraoperative neurophysiologic monitoring.

Combined Motor and Sensory Intraoperative Neuromonitoring for Cervical Spondylotic Myelopathy Surgery Causes Confusion: A Level-1 Diagnostic Study

STUDY DESIGN

Level-1 diagnostic study.

OBJECTIVE

The purpose of this study was to evaluate the sensitivity and specificity of combined motor and sensory intraoperative neuromonitoring (IONM) for cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Intraoperative neuromonitoring during spine surgery began with sensory modalities with the goal of reducing neurological complications. Motor monitoring was later added and purported to further increase sensitivity and specificity when used in concert with sensory monitoring. Debate continues, however, as to whether neuromonitoring reliably detects reversible neurologic changes during surgery or simply adds set-up time, cost, or mere medicolegal reassurance.

METHODS

Neuromonitoring data using combined motor and sensory evoked potentials for 540 patients with CSM undergoing anterior or posterior decompressive surgery were collected prospectively. Patients were examined postoperatively to determine the clinical occurrence of new neurologic deficit which correlated with monitoring alerts recorded per established standard criteria.

RESULTS

The overall incidence of positive IONM alerts was 1.3% (N = 7) all of which were motor alerts. All were false positives as no patient had clinical neurological deterioration post-operatively. The false-positive rate was 1.4% (N = 146) for anterior surgeries and 1.3% (N = 394) for posteriors with no statistical difference between them (P = 1.0, Fisher exact test). There were no false-negative alerts, and all negatives were true negatives (N = 533). The overall sensitivity of detecting a new neurologic deficit was 0%, overall specificity 98.7%.

CONCLUSION

Combined motor and sensory neuromonitoring for CSM patients created a confusing choice between the motor or sensory data when in disagreement in 1.3% of surgical patients. Criterion standard clinical examinations confirmed all motor alerts were false positives. Surgical plan was negatively altered by following false motor alerts early on, but disregarded in later cases in favor of sensory data. Neuromonitoring added set-up time and cost, but without clear benefit in this series.Level of Evidence: 4.

Roadmap for Motor Evoked Potential (MEP) Monitoring for Patients Undergoing Lumbar and Lumbosacral Spinal Fusion Procedures

MEPs are recommended for patients undergoing lumbar and lumbosacral procedures in which intraoperative neuromonitoring (IONM) is being utilized. While electromyography (EMG) provides critical nerve root proximity information, spontaneous EMG discharges are relatively poor at reliably diagnosing spinal nerve root dysfunction. In contrast, research indicates that MEPs are both sensitive and specific in diagnosing evolving spinal nerve root dysfunction. There is conflicting evidence, however, and it must be emphasized that the value of adding MEPs is only realized when practices and techniques are optimized. The ideal anesthetic plan is an optimized total intravenous anesthetic (TIVA) regimen. Selection of appropriate anesthetics and dosing is important for optimizing baseline response amplitudes and promoting diagnostic confidence in analyzing signal changes. An adaptive set of alert criteria that account for baseline amplitude and morphology fluctuations should guide the determination of significant signal change. The therapeutic impact of accurate diagnostic information depends on the timeliness of diagnosis and intervention. Prior to the start of surgery, a plan to obtain MEPs at least once every 10 minutes during the active part of the procedure and after every significant surgical maneuver should be agreed upon, and the intervention plan should include but not be limited to possible removal of hardware and release of retraction or distractive forces. In summary, MEPs can improve monitoring of at-risk nerve root function, but the accuracy and therapeutic impact of such monitoring depend on perioperative planning and communication that optimize use of this modality.

The Italian technical/administrative recommendations for telemedicine in clinical neurophysiology

Recent advances in technology, information technology, Internet networks, and, more recently, fiber optics in industrialized countries allow the exchange of a huge amount of data, in real time, across the globe. The acquisition of increasingly sophisticated technologies has made it possible to develop telemedicine, by which the specialist's evaluation can be carried out on the patient even remotely. In Italy, this very useful tool, although possible from a technological and information technology point of view, has not been developed because of the lack of clear and univocal rules and of major administrative obstacles related to the Italian Public Health System. To promote telemedicine implementation in Italy, the Italian Society of Clinical Neurophysiology and the Italian Society of Telemedicine together with the National Centre for Telemedicine and New Assistive Technologies of the Italian Higher Institute of Health prepared these inter-society recommendations. Because of potential forensic value of these recommendations, they were prepared considering the current regulations and the General Data Protection Regulation and will provide the basis for a Consensus Conference planned to discuss and prepare National Telemedicine Guidelines.

Best Practices in Facial Nerve Monitoring

OBJECTIVES/HYPOTHESIS

Facial nerve monitoring (FNM) has evolved into a widely used adjunct for many surgical procedures along the course of the facial nerve. Even though majority opinion holds that FNM reduces the incidence of iatrogenic nerve injury, there are few if any studies yielding high-level evidence and no practice guidelines on which clinicians can rely. Instead, a review of the literature and medicolegal cases reveals significant variations in methodology, training, and clinical indications.

STUDY DESIGN

Literature review and expert opinion.

METHODS

Given the lack of standard references to serve as a resource for FNM, we assembled a multidisciplinary group of experts representing more than a century of combined monitoring experience to synthesize the literature and provide a rational basis to improve the quality of patient care during FNM.

RESULTS

Over the years, two models of monitoring have become well-established: 1) monitoring by the surgeon using a stand-alone device that provides auditory feedback of facial electromyography directly to the surgeon, and 2) a team, typically consisting of surgeon, technologist, and interpreting neurophysiologist. Regardless of the setting and the number of people involved, the reliability of monitoring depends on the integration of proper technical performance, accurate interpretation of responses, and their timely application to the surgical procedure. We describe critical steps in the technical set-up and provide a basis for context-appropriate interpretation and troubleshooting of recorded signals.

CONCLUSIONS

We trust this initial attempt to describe best practices will serve as a basis for improving the quality of patient care while reducing inappropriate variations.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:S1-S42, 2021.

Application evaluation of intraoperative ultrasound combined with neuro electrophysiological detection in the spinal cord glioma surgery

Objective

To observe application values of intraoperative ultrasound combined with neuro electrophysiological detection in the spinal cord glioma surgery.

Methods

Sixty patients with spinal cord glioma hospitalized in Baoding First Central Hospital from January 2016 to January 2018 were selected, randomly divided into two groups by the random number table method, with 30 cases of each group. PASS software was used to calculate the sample size. The control group was treated with traditional microsurgery, while the experimental group was treated with intraoperative ultrasound combined with neuro electrophysiological testing. The operation time, intraoperative blood loss, postoperative hospital stays, degree of tumor resection, clinical efficacy, recovery of neurological function, recovery of health status, quality of life score, and 2-year recurrence rate of the two groups of patients were observed and compared.

Results

The operation time of the experimental group was longer than that of the control group, and the postoperative hospital stay was shorter than that of the control group. The complete tumor resection rate, complete remission rate and postoperative scale scores of the experimental group were significantly higher than those of the control group, while the recurrence rate within two years was significantly lower than that of the control group. The above differences were statistically significant (p<0.05).

Conclusions

Intraoperative ultrasound combined with neuro-electrophysiological detection for spinal glioma has more adequate protection of nerve function, high clinical complete remission rate, more thorough tumor resection, and lower recurrence rate than traditional microsurgery, which is worthy of clinical application.

Intraoperative Neurophysiological Monitoring During Trigeminal Schwannoma Surgery

Surgical manipulation during skull base surgeries places various cranial nerves (CN) at risk, including the nerves innervating the extraocular muscles. It could be very challenging for the surgeon to identify these cranial nerves due to the distortion of the normal anatomy by the tumors. Despite the recent advancement in technology, surgeries involving the third, fourth, fifth, and sixth cranial nerves still carry a risk of temporary or permanent paralysis of the muscles supplied by these cranial nerves. Intraoperative Neurophysiological Monitoring (IONM) with spontaneous and triggered electromyography (EMG) can help in guiding the surgeon in locating the nerves and avoiding any injury to them during the resection. IONM for extraocular cranial nerves requires highly skilled personnel with knowledge of anatomy and expertise in the placement of the electrodes. Benign tumors of the nerve sheath that arise from the perineural Schwann cells are known as schwannomas. Various cranial nerves might be involved in schwannomas of the head and neck. Trigeminal schwannomas are rare tumors. In this report, we describe the setup and stimulation technique and parameters as well as the benefits of utilizing IONM during the aggressive resection of a trigeminal schwannoma. The main purpose of utilizing IONM during these high-risk surgical procedures is to minimize any intraoperative damage to the neural structures involved.

Neurophysiological monitoring of spinal cord function during spinal deformity surgery: 2020 SRS neuromonitoring information statement

The Scoliosis Research Society has developed an updated information statement on intraoperative neurophysiological monitoring of spinal cord function during spinal deformity surgery. The statement reviews the risks of spinal cord compromise associated with spinal deformity surgery; the statement then discusses the various modalities that are available to monitor the spinal cord, including somatosensory-evoked potentials, motor-evoked potentials, and electromyographic (EMG) options. Anesthesia considerations, the importance of a thoughtful team approach to successful monitoring, and the utility of checklists are also discussed. Finally, the statement expresses the opinion that utilization of intraoperative neurophysiological spinal cord monitoring in spinal deformity surgery is the standard of care when the spinal cord is at risk.

Consensus document for multimodal intraoperatory neurophisiological monitoring in neurosurgical procedures. Basic fundamentals

The present work aims to establish a guide to action, agreed by anaesthesiologists and neurophysiologists alike, to perform effective intraoperative neurophysiological monitoring for procedures presenting a risk of functional neurological injury, and neurosurgical procedures. The first section discusses the main techniques currently used for intraoperative neurophysiological monitoring. The second exposes the anaesthetic and non-anaesthetic factors that are likely to affect the electrical records of the nervous system structures. This section is followed by an analysis detailing the adverse effects associated with the most common techniques and their use. Finally, the last section describes a series of guidelines to be followed upon the various intraoperative clinical events.

Multimodality Intraoperative Neurophysiological Monitoring (IONM) During Shoulder Surgeries

Introduction: The purpose of this study is to identify the advancing role of Intraoperative Neurophysiological Monitoring (IONM) in detecting and preventing nerve injuries during shoulder surgery procedures. Methods: We performed a retrospective analysis of IONM data from ten shoulder procedures. The patients consisted of nine females and one male with ages ranging from 67 to 81 years (median: 74 years). IONM modalities utilized were bilateral Somatosensory Evoked Potentials (SSEP), Transcranial Motor Evoked Potentials (TCeMEP), ipsilateral Electromyogram (EMG) from upper extremity muscles and Train of four (TOF) recordings. Results: A decrease in signals was noted in three patients (30%). Only upper SSEP amplitude decreased in one patient; both upper extremity SSEP and TCeMEP decreased in two patients. Only one patient had poor baseline radial nerve SSEP that improved during the surgery. We performed spontaneous EMG (s-EMG) in all ten patients and successfully recorded triggered (t-EMG) in seven patients (71.4%). In one patient, SSEP and TCeMEP did not improve, and the patient woke up with deficits. Conclusions: In this small series, we were able to identify real-time impending nerve injury. The use of IONM alerted and may have prevented intraoperative nerve injury in 30% of the patients in this series. In one patient, SSEP and TCeMEP did not recover even after the intervention due to severe blood loss. The patient woke up with sensory and motor deficits. The utilization of multimodality IONM can be helpful due to signal changes, therefore minimizing the frequency of nerve injury and deficits.

Neural Monitoring for Robotic Abdominal Wall Reconstruction

Introduction:

Positioning-related neural injuries are an inherent risk in surgery, particularly in robotic-assisted abdominal wall reconstruction because of unique patient positioning and increased operative times. The implementation of intraoperative neurophysiological monitoring should be considered in such cases.

Methods:

This was a two-armed study with one prospective intervention group and one retrospective control group. All patients underwent robotic abdominal wall reconstruction at an academic center. The prospective arm underwent robotic reconstruction from January through July 2019. The retrospective database reviewed patients who underwent the same procedure from August 2015 through July 2018. Factors assessed included: demographics (age, gender, body mass index, comorbidities), surgical details (American Society of Anesthesiologists class, procedure, operative time, positioning), outcomes (length of stay, 30-d readmission, reoperation), and any new-onset intraoperative or postoperative neuropathy. Patients were seen in the clinic postoperatively at weeks 1 and 6.

Results:

Ten patients were included in the prospective arm. All received intraoperative neurophysiological monitoring using somatosensory evoked potentials. They were compared with 47 patients in the retrospective arm who underwent surgery without intraoperative neurophysiological monitoring. One position-related neural response from baseline was detected intraoperatively in the prospective arm; however, there were no peripheral neurological symptoms present postoperatively. Two patients in the control group developed transient peripheral neuropathies that resolved within 6 weeks. Demographics, surgical procedures, and length of surgery were similar in both groups. The prospective group had a higher rate of preoperative neuropathy and intraoperative use of vasopressors.

Conclusion:

Incorporation of neurophysiological monitoring in robotic surgery is feasible and may lead to the prevention and reduction in positioning-related injuries.