Three-Level Concavity Apical Pediculectomy During Intraoperative Neuromonitoring Loss: Following the Checklist Resulted in an Ambulatory Patient.

Adolescent idiopathic scoliosis is the most common form of scoliosis, with severe cases leading to a decline in patients with worsening angulation of deformity. Technical nuances of spinal flexibility and cord type based on the extent of the deformity may impact operating safety and outcome, with risks including neurological loss during and after surgical intervention. Here we present a case of posterior osteotomy and correction of a patient with adolescent idiopathic scoliosis with a T2 - L3 fusion in which transcranial motor evoked potentials (TcMEPs) and somatosensory evoked potentials (SSEPs) were lost intraoperatively, thus requiring application of operative consensus guidelines for the loss of neuromonitoring data. Particularly, the discussion focuses on the decision-making process that resulted in the complete recovery of TcMEPs and SSEPs post-operatively.

Management Principles in a Case of True-positive Loss of Neuromonitoring Signals during Scoliosis Surgery: A Case Report.

Introduction: Multimodal intraoperative neuromonitoring (IOM) is essential in scoliosis surgery. This is affected by misplaced instrumentation, cord trauma, hemodynamic instability, and anesthesia. We present an irreversible loss of IOM without identifiable intra-operative cause to highlight its occurrence and discuss post-operative investigations and management. Case Report: A 14-year-old girl with adolescent idiopathic scoliosis, no co-morbidities, and normal spinal magnetic resonance imaging (MRI) underwent posterior spinal fusion. During screw placement, bilateral motor evoked potentials (MEPs) and right somatosensory evoked potentials (SSEPs) were lost in the legs. All screws were removed with no evidence of cortical breach. Left leg responses gradually improved, but there was no recovery of right leg SSEPs or MEPs. Subsequently, the procedure was abandoned. The patient had reduced right leg strength (3/5) and sensation with the left leg was normal. Immediate post-operative spinal MRI identified no abnormality. Computed tomography (CT) showed no cortical breach with satisfactory pedicle screw tracts. Repeat MRI (day 7) showed high T2-signal within the cord at T11 indicating ischemia. Gradual neurological recovery occurred and on day 15, repeat neurophysiology found reproducible SSEPs and MagStim MEPs. The patient underwent revision posterior fusion with single rod correction without complication and IOM was maintained. By day 24, the patient had 5/5 power and normal sensation in both legs. Good scoliosis correction was achieved and maintained at 3-year follow-up. Conclusion: This patient represents a vascular event affecting the lower spinal cord and highlights the role of sequential imaging and pre-operative neurophysiology including MagStim in deciding when to proceed with revision surgery while reducing risk using conservative techniques.

Risk factors and operative risk of large vessel occlusion and stroke during cardiac surgery.

OBJECTIVE: Perioperative Large Vessel Occlusions (LVOs) occurring during and following surgery are of immense clinical importance. As such, we aim to present risk factors and test if the Society of Thoracic Surgery (STS) mortality and stroke risk scores can be used to assess operative risk. METHODS: Using data containing 7 index cardiac operations at a single tertiary referral center from 2010 to 2022, logistic and multivariate regression analysis was performed to identify factors that correlate to higher operative LVO and stroke rate. Odds ratios and confidence intervals were also obtained to test if the STS-Predicted Risk of Mortality (PROM) and -Predicted Risk of Stroke (PROS) scores were positively correlated to operative LVO and stroke rate. RESULTS: Multivariate modeling showed primary risk factors for an operative LVO were diabetes (OR: 1.727 [95 % CI: 1.060-2.815]), intracranial or extracranial carotid stenosis (OR: 3.661 [95 % CI: 2.126-6.305]), and heart failure as defined by NYHA class (Class 4, OR: 3.951 [95 % CI: 2.092-7.461]; compared to Class 1). As the STS-PROM increased, the relative rate of LVO occurrence increased (very high risk, OR: 6.576 [95 % CI: 2.92-14.812], high risk, OR: 2.667 [1.125-6.322], medium risk, OR: 2.858 [1.594-5.125]; all compared to low risk). STS-PROS quartiles showed a similar relation with LVO risk (quartile 4, OR: 7.768 [95 % CI: 2.740-22.027], quartile 3, OR: 5.249 [1.800-15.306], quartile 2, OR:2.980 [0.960-9.248]; all compared to quartile 1). CONCLUSIONS: Patients with diabetes, carotid disease and heart failure are at high risk for operative LVO. Both STS-PROM and -PROS can be useful metrics for preoperative measuring of LVO risks.

Machine learning allows expert level classification of intraoperative motor evoked potentials during neurosurgical procedures.

OBJECTIVE: To develop and evaluate machine learning (ML) approaches for muscle identification using intraoperative motor evoked potentials (MEPs), and to compare their performance to human experts. BACKGROUND: There is an unseized opportunity to apply ML analytic techniques to the world of intraoperative neuromonitoring (IOM). MEPs are the ideal candidates given the importance of their correct interpretation during a surgical operation to the brain or the spine. In this work, we develop and test a set of different ML models for muscle identification using intraoperative MEPs and compare their performance to human experts. In addition, we provide a review of the available literature on current ML applications to IOM data in neurosurgery. METHODS: We trained and tested five different ML classifiers on a MEP database developed from six different muscles in patients who underwent brain or spinal cord surgery. MEPs were obtained by both transcranial (TES) and direct cortical stimulation (DCS) protocols. The models were evaluated within a single patient and on previously unseen patients, considering signals from TES and DCS both independently and mixed. Ten expert neurophysiologists classified a set of 50 randomly selected MEPs, and their performance was compared to the best performing model. RESULTS: A total of 25.423 MEPs were included in the study. Random Forest proved to be the best performing model with 99 % accuracy in the single patient dataset task and a 78 %-94 % accuracy range on previously unseen patients. The model performance was maximized by representing MEPs as a set of features typically employed in signal processing compared to traditional neurophysiological parameters. The classification ability of the Random Forest model between six different muscles and across different MEP acquisition modalities (79 %) significantly exceeded that of human experts (mean 48 %). CONCLUSIONS: Carefully selected ML models proved to have reliable capacity of extracting meaningful information to classify intraoperative MEPs using a limited number of features, proving robustness across patients and signal acquisition modalities, outperforming human experts, and with the potential to act as decision support systems to the IOM team. Such encouraging results lay the path to further explore the underlying nature of clinically important signals, with the aim to continue to produce useful applications to make surgeries safer and more efficient.

The trapezius plane block: Extended use in perioperative pain management in nerve transfer surgeries.

Nerve transfer surgery has emerged as a promising approach to restoring function in paralyzed muscles. The trapezius plane block (TPB) blocks the thoracic branches of the posterior primary rami, providing extended analgesia in nerve transfer surgeries. The case report describes the analgesia profiling of a young man who suffered a traumatic pan-brachial plexus injury and underwent a spinal accessory nerve to the suprascapular nerve transfer. TPB was utilized as a part of multimodal analgesia. TPB represents an advancement in regional anesthesia, providing extended analgesia and reducing opioid consumption. TPB can promote patient comfort and facilitate early mobilization.

Detecting and Addressing Secondary Neural Injuries in Cranial Surgery: Case Report.

Intraoperative neurophysiological monitoring (IONM) is instrumental in mitigating neurological deficits following cranial and spinal procedures. Despite extensive research on IONM's ability to recognize limb-malposition-related issues, less attention has been given to other secondary neural injuries in cranial surgeries. A comprehensive multimodal neuromonitoring approach was employed during a left frontal craniotomy for tumor resection. The electronic medical record was reviewed in detail in order to describe the patient's clinical course. The patient, a 46-year-old female, underwent craniotomy for excision of a meningioma. Deteriorations in somatosensory evoked potential and transcranial motor evoked potential recordings identified both a mal-positioned limb as well as an infiltrated intravenous (IV) line in the arm contralateral to the surgical site. The IONM findings for the infiltrated IV were initially attributed to potential limb malposition until swelling and blistering of the limb were appreciated and investigated. The timely identification and management of the infiltrated IV and adjustment of limb positioning contributed to the patient's recovery, avoiding fasciotomy, with no postoperative neurological deficits. This case is the first published demonstration of the utility of IONM in detecting IV infiltration. This early recognition facilitated early intervention, saving the patient from a potential fasciotomy and enabling their recovery with no postoperative neurological deficits. The findings from this single case highlight the necessity for vigilant and dynamic application of IONM techniques to enhance patient safety and outcomes in neurosurgical procedures. Further research is needed to explore broader applications and further optimize the detection capabilities of IONM.

Implementation of a Standardized Protocol for Recurrent Laryngeal Nerve Monitoring Reduces False Negative Results During Neck Surgery: A Quality Control Case Study.

Recurrent laryngeal nerve (RLN) injury during neck surgery can cause significant morbidity related to vocal cord (VC) dysfunction. VC electromyography (EMG) is used to aid in the identification of the RLN and can reduce the probability of inadvertent surgical injury. Errors in the placement of specialized EMG endotracheal tubes (ETT) can result in unreliable signals, false-negative responses, or no response when stimulating the RLN. We describe a novel educational protocol developed to optimize uniformity in the placement of ETTs to improve the reliability of RLN monitoring. An intraoperative neuromonitoring database was queried for all neck surgeries requiring RLN monitoring. Data points extracted for all cases requiring EMG monitoring for neck procedures. Free running and stimulated EMG were monitored and continuously recorded by a certified technologist. Alerts were compared between 2013-14 and 2015-18 using a two-sample test of proportions. Significant reductions in alerts were demonstrated after protocol implementation (7.5% pre-implementation to 2.1% post). Alerts were compared between 2013-14 (overall alert rate of 1.8%, pre-implementation period) and 2015-18 (overall alert rate of 2.8%, post-implementation period). Protocolization for placement of EMG-ETT improved accuracy in EMG monitoring. In the follow-up cohort of 1,080 patients, use of this protocol continued to reduce the rate of alerts related to ETT malposition, confirming the sustainability of this intervention through routine education. The risk of nerve injury is reduced when the rate of alerts is minimized. Scheduled or continuous protocol education of anesthesia personnel should continue to ensure compliance with protocol.

Intraoperative pelvic neuromonitoring based on bioimpedance signals: a new method analyzed on 30 patients.

PURPOSE: Increasing importance has been attributed in recent years to the preservation of the pelvic autonomic nerves during rectal resection to achieve better functional results. In addition to improved surgical techniques, intraoperative neuromonitoring may be useful. METHODS: This single-arm prospective study included 30 patients who underwent rectal resection performed with intraoperative neuromonitoring by recording the change in the tissue impedance of the urinary bladder and rectum after stimulation of the pelvic autonomic nerves. The International Prostate Symptom Score, the post-void residual urine volume and the Low Anterior Resection Syndrome Score (LARS score) were assessed during the 12-month follow-up period. RESULTS: A stimulation-induced change in tissue impedance was observed in 28/30 patients (93.3%). In the presence of risk factors such as low anastomosis, neoadjuvant radiotherapy and a deviation stoma, an average increase of the LARS score by 9 points was observed 12 months after surgery (p = 0,04). The function of the urinary bladder remained unaffected in the first week (p = 0,7) as well as 12 months after the procedure (p = 0,93). CONCLUSION: The clinical feasibility of the new method for pelvic intraoperative neuromonitoring could be verified. The benefits of intraoperative pelvic neuromonitoring were particularly evident in difficult intraoperative situations with challenging visualization of the pelvic nerves.

"Letter to the editor, clinical characteristics and outcomes after trigeminal schwannoma resection: a multi-institutional experience".

The recent article "Clinical characteristics and outcomes after trigeminal schwannoma resection: a multi-institutional experience" by Nandoliya et al. offers critical insights into the management of trigeminal schwannomas (TS). This multi-institutional study, encompassing 30 patients over 18 years, highlights various surgical approaches, achieving gross-total resection in 53% of cases, and emphasizes the balance between resection and neurological preservation. The use of intraoperative neuromonitoring in 77% of cases is noted for minimizing morbidity. Despite a 13% complication rate, most were transient. Long-term follow-up data show a low recurrence rate, advocating for ongoing surveillance. The study underscores the importance of tailored surgical strategies, and the discussion of classification systems aids in contextual understanding. While the findings are robust, further research into adjuvant therapies and emerging technologies is warranted. This comprehensive overview advances our understanding of TS, promoting a patient-centered approach to surgical management.

The INMSG Survey on the Loss of Signal Management on the First Side During Planned Bilateral Thyroid Surgery.

BACKGROUND: The aim of this study is to describe the management and associated follow-up strategies adopted by thyroid surgeons with different surgical volumes when loss of signal (LOS) occurred on the first side of planned bilateral thyroid surgery, and to further define the consensus on intraoperative neuromonitoring (IONM) applications. METHODS: The International Neural Monitoring Study Group (INMSG) web-based survey was sent to 950 thyroid surgeons worldwide. The survey included information on the participants, IONM team/equipment/procedure, intraoperative/postoperative management of LOS, and management of LOS on the first side of thyroidectomy for benign and malignant disease. RESULTS: Out of 950, 318 (33.5%) respondents completed the survey. Subgroup analyses were performed based on thyroid surgery volume: <50 cases/year (n = 108, 34%); 50 to 100 cases/year (n = 69, 22%); and >100 cases/year (n = 141, 44.3%). High-volume surgeons were significantly (P < .05) more likely to perform the standard procedures (L1-V1-R1-S1-S2-R2-V2-L2), to differentiate true/false LOS, and to verify the LOS lesion/injury type. When LOS occurs, most surgeons arrange otolaryngologists or speech consultation. When first-side LOS occurs, not all respondents decided to perform stage contralateral surgery, especially for malignant patients with severe disease (eg, extrathyroid invasion and poorly differentiated thyroid cancer). CONCLUSIONS: Respondents felt that IONM was optimized when conducted under a collaborative team-based approach, and completed IONM standard procedures and management algorithm for LOS, especially those with high volume. In cases of first-site LOS, surgeons can determine the optimal management of disease-related, patient-related, and surgical factors. Surgeons need additional education on LOS management standards and guidelines to master their decision-making process involving the application of IONM.

How to Define and Meet Blood Pressure Targets After Traumatic Brain Injury: A Narrative Review.

BACKGROUND: Traumatic brain injury (TBI) poses a significant challenge to healthcare providers, necessitating meticulous management of hemodynamic parameters to optimize patient outcomes. This article delves into the critical task of defining and meeting continuous arterial blood pressure (ABP) and cerebral perfusion pressure (CPP) targets in the context of severe TBI in neurocritical care settings. METHODS: We narratively reviewed existing literature, clinical guidelines, and emerging technologies to propose a comprehensive approach that integrates real-time monitoring, individualized cerebral perfusion target setting, and dynamic interventions. RESULTS: Our findings emphasize the need for personalized hemodynamic management, considering the heterogeneity of patients with TBI and the evolving nature of their condition. We describe the latest advancements in monitoring technologies, such as autoregulation-guided ABP/CPP treatment, which enable a more nuanced understanding of cerebral perfusion dynamics. By incorporating these tools into a proactive monitoring strategy, clinicians can tailor interventions to optimize ABP/CPP and mitigate secondary brain injury. DISCUSSION: Challenges in this field include the lack of standardized protocols for interpreting multimodal neuromonitoring data, potential variability in clinical decision-making, understanding the role of cardiac output, and the need for specialized expertise and customized software to have individualized ABP/CPP targets regularly available. The patient outcome benefit of monitoring-guided ABP/CPP target definitions still needs to be proven in patients with TBI. CONCLUSIONS: We recommend that the TBI community take proactive steps to translate the potential benefits of personalized ABP/CPP targets, which have been implemented in certain centers, into a standardized and clinically validated reality through randomized controlled trials.

Awake craniotomy in pediatric low-grade glioma: barriers and future directions.

INTRODUCTION: The goal of surgical management in pediatric low-grade gliomas (pLGGs) is gross total resection (GTR), as it is considered curative with favorable long-term outcomes. Achieving GTR can be challenging in the setting of eloquent-region gliomas, in which resection may increase risk of neurological deficits. Awake craniotomy (AC) with intraoperative neurofunctional mapping (IONM) offers a promising approach to achieve maximal resection while preserving neurological function. However, its adoption in pediatric cases has been hindered, and barriers to its adoption have not previously been elucidated. FINDINGS: This review includes two complementary investigations. First, a survey study was conducted querying pediatric neurosurgeons on their perceived barriers to the procedure in children with pLGG. Next, these critical barriers were analyzed in the context of existing literature. These barriers included the lack of standardized IONM techniques for children, inadequate surgical and anesthesia experience, concerns regarding increased complication risks, doubts about children's ability to tolerate the procedure, and perceived non-indications due to alternative monitoring tools. CONCLUSION: Efforts to overcome these barriers include standardizing IONM protocols, refining anesthesia management, enhancing patient preparation strategies, and challenging entrenched beliefs about pediatric AC. Collaborative interdisciplinary efforts and further studies are needed to establish safety guidelines and broaden the application of AC, ultimately improving outcomes for children with pLGG.

A screening for cerebral deoxygenation during VT ablations in patients with structural heart disease.

BACKGROUND: Patients undergoing ventricular tachycardia (VT) ablation often present with structural heart disease (SHD) and reduced ejection fraction. Inducing VT by programmed electrical stimulation (PES) puts these patients at risk for hemodynamic instability and cerebral hypoperfusion. OBJECTIVE: The present study screens for cerebral oxygen desaturation phases (ODPs) in patients undergoing VT ablation. METHODS: Forty-seven patients (age 61 ± 14 years, 72% males) underwent ablation of sustained VT with simultaneous neuromonitoring using near-infrared spectroscopy (NIRS). RESULTS: Analysis of NIRS signal identified ODPs in 29 patients (62%). ODPs were associated with a higher prevalence of ischemic heart disease (IHD) (45% vs. 11%, p = 0.024), previous VT episodes (n = 16 vs. 4, p = 0.018), and VTs inducible by PES (n = 2.4 vs. 1.2, p = 0.004). Patients with ODPs were more likely to be admitted to intensive care unit (ICU) (78% vs. 33%, p = 0.005) and had more in-hospital VT recurrences (24% vs. 0%, p = 0.034). No differences were observed in VT recurrence rates after hospital discharge (41.4% vs. 44.4%, p = 0.60) and left ventricular ejection fraction (34% vs. 38%, p = 0.567). IHD (OR: 32.837, p = 0.006), ICU admission (OR: 14.112, p = 0.013), and the number of VTs inducible at PES (OR: 2.705, p = 0.015) were independently associated with ODPs. CONCLUSIONS: This study registers episodes of cerebral hypoperfusion in 62% of patients undergoing VT ablation and identifies IHD and the number of VTs inducible at PES as possible risk factors for these episodes.

"Roberto Rodríguez" General Teaching Hospital of Moron, Ciego De Avila, Cuba, Neurosurgery and Pediatric Intensive Care Services Pediatric Neuromonitoring in Severe Head Trauma.

Among all types of trauma in children, traumatic brain injury has the greatest potential for the development of devastating consequences, with nearly three million affected each year in the world. A controlled, nonrandomized experimental study was carried out in pediatric patients with severe traumatic brain injury, whose objective was to evaluate the use of continuous multimodal neuromonitoring (MMN) of intracranial parameters as a guide in the treatment of children of different age-groups. The patients were divided into two groups according to the treatment received; clinical and imaging monitoring was performed in both. Group I included those whose treatment was guided by MMN of intracranial parameters such as intracranial pressure, cerebral perfusion pressure, and intracranial compliance, and group II included those who had only clinical and imaging monitoring. Eighty patients were studied, 41 in group I and 39 in group II. There were no significant differences between the groups with respect to the sociodemographic variables and the results; as a consequence, both forms of treatment were outlined, for patients with MMN and for those who only have clinical and imaging monitoring. It is concluded that both treatment schemes can be used depending on technological availability, although the scheme with MMN is optimal.

The Effect of the TiO2 Anodization Layer in Pedicle Screw Conductivity: An Analytical, Numerical, and Experimental Approach.

The electrical stimulation of pedicle screws is a technique used to ensure its correct placement within the vertebrae pedicle. Several authors have studied these screws' electrical properties with the objective of understanding if they are a potential source of false negatives. As titanium screws are anodized with different thicknesses of a high electrical resistance oxide (TiO2), this study investigated, using analytical, numerical, and experimental methods, how its thickness may affect pedicle screw's resistance and conductivity. Analytical results have demonstrated that the thickness of the TiO2 layer does result in a significant radial resistance increase (44.21 mΩ/nm, for Ø 4.5 mm), and a decrease of conductivity with layers thicker than 150 nm. The numerical approach denotes that the geometry of the screw further results in a decrease in the pedicle screw conductivity, especially after 125 nm. Additionally, the experimental results demonstrate that there is indeed an effective decrease in conductivity with an increase in the TiO2 layer thickness, which is also reflected in the screw's total resistance. While the magnitude of the resistance associated with each TiO2 layer thickness may not be enough to compromise the ability to use anodized pedicle screws with a high-voltage electrical stimulator, pedicle screws should be the subject of more frequent electrical characterisation studies.

Redesigned Electrodes for Improved Intraoperative Nerve Conduction Studies during the Treatment of Peripheral Nerve Injuries.

Traumatic peripheral nerve injuries (PNI), present with symptoms ranging from pain to loss of motor and sensory function. Difficulties in intraoperative visual assessment of nerve functional status necessitate intraoperative nerve conduction studies (INCSs) by neurosurgeons and neurologists to determine the presence of functioning axons in the zone of a PNI. This process, also referred to as nerve "inching", uses a set of stimulating and recording electrode hooks to lift the injured nerve from the surrounding surgical field and to determine whether an electrical stimulus can travel through the zone of injury. However, confounding electrical signal artifacts can arise from the current workflow and electrode design, particularly from the mandatory lifting of the nerve, complicating the definitive assessment of nerve function and neurosurgical treatment decision-making. The objective of this study is to describe the design process and verification testing of our group's newly designed stimulating and recording electrodes that do not require the lifting or displacement of the injured nerve during INCSs. Ergonomic in vivo analysis of the device within a porcine model demonstrated successful intraoperative manipulation of the device, while quantitative nerve action potential (NAP) signal analysis with an ex vivo simulated "inching" procedure on healthy non-human primate nerve tissue demonstrated excellent reproducible recorded NAP fidelity and the absence of NAP signal artifacts at all points of recording. Lastly, electrode pullout force testing determined maximum forces of 0.43 N, 1.57 N, and 3.61 N required to remove the device from 2 mm, 5 mm, and 1 cm nerve models, respectively, which are well within established thresholds for nerve safety. These results suggest that these new electrodes can safely and successfully perform accurate PNI assessment without the presence of artifacts, with the potential to improve the INCS standard of care while remaining compatible with currently used neurosurgical technology, infrastructure, and clinical workflows.

Risk predictive score and cord morphology classification for intraoperative neuromonitoring alerts in kyphosis surgery.

BACKGROUND: Intraoperative neuromonitoring (IONM) alert is one of the worrying events of kyphosis corrective surgery, which can result in a postoperative neurological deficit. To our knowledge, there is no risk prediction score to predict such events in patients undergoing kyphosis surgery. PURPOSE: To develop a new preoperative MRI-based cord morphology classification (CMC) and risk prediction score for predicting IONM alerts in patients with kyphotic deformity. STUDY DESIGN: Retrospective analysis of prospectively collected data. PATIENT SAMPLE: About 114 patients undergoing surgical correction for kyphotic deformity. OUTCOME MEASURES: Intraoperative neuromonitoring alerts and postoperative neurological status using AIS grading. METHODS: Kyphotic deformity patients undergoing posterior spinal fusion were retrospectively reviewed. Based on the morphology of the spinal cord and surrounding CSF in MRI, there are 5 types of cord. Type 1 (normal cord): circular cord with surrounding visible CSF between the cord and the apex, Type 2 (flattened cord): cord with <50% distortion at the apex with obliteration of the anterior CSF; Type 3 (deformed cord): cord with >50% distortion at the apex with complete obliteration of the surrounding CSF; Type 4 (stretched cord): the cord is stretched and atrophied over the apex of the curve. Type 5 (translated cord): horizontal translation of the cord at the apex with buckling collapse of the vertebral column. Preoperative radiographs were used to measure the preoperative sagittal cobbs angle, sagittal deformity angular ratio (S-DAR), sagittal vertical axis (SVA), apex of the curve, and type of kyphosis. Clinical data like the duration of symptoms, clinical signs of myelopathy, neurological status (AIS grade), grade of myelopathy using the mJOA score, and type of osteotomy were documented. Multivariate logistic regression was used to determine the risk factors for IONM alerts and the risk prediction score was developed which was validated with new cohort of 30 patients. RESULTS: A total of 114 patients met the inclusion criteria. IONM alerts were documented in 33 patients (28.9%), with full recovery of the signal in 25 patients and a postoperative deficit in 8 patients. Rate of IONM alerts was significantly higher in Type 5 (66%), followed by Type 4 (50%), Type 3 (21.1%), Type 2 (11.1%), and Type 1 (11.1%) (p-value<.001). Based on multiple logistic regression, 7 factors, namely preoperative neurological status, mJOA score≤6, presence of signs of myelopathy, apex of the curve above T5, preoperative sagittal cobbs, S-DAR, and MRI-based CMC, were identified as risk predictors. The value for the risk factors varies from 0 to 4, and the maximum total risk score was 13. The cut-off value of 6 had good sensitivity (84.9%) and specificity (77.8%) indicating a high risk for IONM alerts. The AUC of the predictive model was 0.92, indicating excellent discriminative ability. CONCLUSION: We developed and validated a risk predictive score that identifies patients at risk of IONM alerts during kyphosis surgery. Identification of such high-risk patients (risk score≥6) helps in proper evaluation and preoperative counselling and helps in providing a proper evidence-based reference for treatment strategies.

Three montages for Transcranial electric stimulation in predicting the early post-surgery outcome of the facial nerve functioning.

OBJECTIVE: We assessed the Transcranial Electrical Stimulation (TES)-induced Corticobulbar-Motor Evoked Potentials (Cb-MEPs) evoked from Orbicularis Oculi (Oc) and Orbicularis Oris (Or) muscles with FCC5h/FCC6h-Mz, C3/C4-Cz and C5/C6/-Cz stimulation, during IntraOperative NeuroMonitoring (IONM) in 30 patients who underwent skull-base surgery. METHODS: before (T0) and after (T1) the surgery, we compared the peak-to-peak amplitudes of Cb-MEPs obtained from TES with C3/C4-Cz, C5/C6-Cz and FCC5h/FCC6h-Mz. Then, we compared the response category (present, absent and peripheral) related to different montages. Finally, we classified the Cb-MEPs data from each patient for concordance with clinical outcome and we assessed the diagnostic measures for Cb-MEPs data obtained from FCC5h/FCC6h-Mz, C3/C4-Cz and C5/C6-Cz TES stimulation. RESULTS: Both at T0 and T1, FCC5h/FCC6h-Mz stimulation evoked larger Cb-MEPs than C3/C4-Cz, less peripheral responses from direct activation of facial nerve than C5/C6-Cz. FCC5h/FCC6h-Mz stimulation showed the best accuracy and specificity of Cb-MEPs for clinical outcomes. CONCLUSIONS: FCC5h/FCC6h-Mz stimulation showed the best performances for monitoring the facial nerve functioning, maintaining excellent diagnostic measures even at low stimulus voltages. SIGNIFICANCE: We demonstrated that FCC5h/FCC6h-Mz TES montage for Cb-MEPs in IONM has good accuracy in predicting the post-surgery outcome of facial nerve functioning.

Advanced neuromonitoring powered by ICM+ and its place in the Brand New AI World, reflections at the 20th anniversary boundary.

Introduction: Adoption of the ICM+® brain monitoring software by clinical research centres worldwide has been continuously growing over the past 20 years. This has necessitated ongoing updates to accommodate evolving neuromonitoring research needs, including recent explosion of artificial intelligence (AI). Research question: We sought to provide an update on the current features of the software. In particular, we aimed to highlight the new options of integrating AI models. Material and methods: We reviewed all currently available ICM+ analytical areas and discussed potential AI based extensions in each. We tested a proof-of-concept integration of an AI model and evaluated its performance for real-time data processing. Results: ICM+ current analytical tools serve both real-time (bed-side) and offline (file based) analysis, including the calculation engine, Signal Calculator, Custom Statistics, Batch tools, ScriptLab and charting. The ICM+ Python plugin engine allows to execute custom Python scripts and take advantage of complex AI frameworks. For the proof-of-concept, we used a neural network convolutional model with 207,000 trainable parameters that classifies morphology of intracranial pressure (ICP) pulse waveform into 5 pulse categories (normal to pathological plus artefactual). When evaluated within ICM+ plugin script on a Windows 10 laptop the classification of a 5 min ICP waveform segment took only 0.19s with a 2.3s of initial, one-off, model loading time required. Conclusions: Modernised ICM+ analytical tools, reviewed in this manuscript, include integration of custom AI models allowing them to be shared and run in real-time, facilitating rapid prototyping and validating of new AI ideas at the bed-side.

Screw Stimulation Thresholds for Neuromonitoring in Minimally Invasive Oblique Lateral Lumbar Interbody Fusion (OLLIF): A Correlational Study.

INTRODUCTION: This study presents findings from an investigation into the correlation of neuromonitoring techniques in minimally invasive lumbar fusions and their open counterparts regarding acceptable thresholds for screw stimulation. The threshold for acceptable stimulation value for open surgery has been established. The study compared acceptable thresholds for open pedicle screws where there is more connection between the screw and the soft tissue. METHODS: The neuromonitoring data of 17 patients who underwent oblique lateral lumbar interbody fusion (OLLIF) procedures between September 2023 to May 2024 were reviewed. Neuromonitoring was conducted throughout surgeries, recording stimulation thresholds for pedicle screws insulated and uninsulated, to simulate the environment of a screw during open and minimally invasive surgery respectively. Patients' BMI was also collected for potential correlation analysis. RESULTS: Results indicate a discernible correlation between stimulation thresholds in open and minimally invasive surgeries, but no definitive correlation with BMI due to sample size limitations. Though a significant correlation between the two stimulating styles is apparent, there is a good correlation to suggest what threshold should determine a standard stimulation threshold for minimally invasive surgeries. CONCLUSION: The study emphasizes the need for refined neuromonitoring strategies in minimally invasive spinal fusion (MISF) surgeries to ensure patient safety and surgical effectiveness. Further research with larger cohorts is recommended to establish optimized protocols that have a clearly defined amplitude for MISF thresholds.