Advancing Intraoperative Neurophysiological Monitoring With Human Reflexes.

Human reflexes are simple motor responses that are automatically elicited by various sensory inputs. These reflexes can provide valuable insights into the functioning of the nervous system, particularly the brainstem and spinal cord. Reflexes involving the brainstem, such as the blink reflex, laryngeal adductor reflex, trigeminal hypoglossal reflex, and masseter H reflex, offer immediate information about the cranial-nerve functionality and the overall state of the brainstem.

The blink reflex and its modulation - Part 1: Physiological mechanisms.

The blink reflex (BR) is a protective eye-closure reflex mediated by brainstem circuits. The BR is usually evoked by electrical supraorbital nerve stimulation but can be elicited by a variety of sensory modalities. It has a long history in clinical neurophysiology practice.

Continuous intraoperative neuromonitoring of the recurrent laryngeal nerve by eliciting the laryngeal adductor reflex (LAR-CIONM).

The laryngeal adductor reflex (LAR) is a life-sustaining airway protective mechanism that serves to shield the lower airways from inhaled foreign bodies. Over the past half century, the LAR has been extensively investigated and its dysfunction has been linked to far-ranging pathologies, from dysphagia to sudden infant death syndrome. Over the past 6 years, specific electromyographic waves in the LAR response have been used to devise a methodology for monitoring the vagus and recurrently laryngeal nerves during surgical procedures.

Median nerve somatosensory evoked potential alarm related to head and neck positioning for carotid surgery.

Head positioning in carotid surgery represents an often overlooked but sensitive period in the surgical plan. A 53-year-old male presented a significant decrement in median nerve somatosensory evoked potential (mSEP) following head and neck positioning for carotid pseudoaneurysm repair before skin incision.Neurophysiological monitoring was performed with mSEP and electroencephalography early during the patient's preparation and surgery.

Unexpected median SEPs fluctuations during brain cavernous malformation resection with no post-operative deficit.

Median nerve somatosensory evoked potentials (SEPs) may present changes during cavernous malformation (CM) resection unrelated to new post-operative sensory deficits. We performed intraoperative neurophysiological monitoring of median SEPs (m-SEPs) in three patients who underwent CM resection (surgery) near the sensory-motor cortex. The only preoperative clinical manifestations in all patients were seizures.

Methodology for eliciting the brainstem trigeminal-hypoglossal reflex in humans under general anesthesia.

Objective: Brainstem trigeminal-hypoglossal reflexes (THRs), also known as the jaw-tongue reflexes, coordinate the position of the tongue in the mouth in relation to the jaw movement during oromotor behaviors such as mastication, swallowing, vocalization, and breathing. Their use in brainstem surgery however, has never been assessed in spite of its potential benefit possibly due to the lack of a methodology to elicit these reflexes under general anesthesia.

Methods: We proposed a technique to elicit the THRs during total intravenous anesthesia (TIVA) consisting on a V3 infrazygomatic train stimulation paradigm and recording from the Styloglossus (31 patients) and the Genioglossus (21 patients) muscles to elicit long latency responses.

Clarifying optimal outcome measures in intermittent and continuous laryngeal neuromonitoring.

Background: Intraoperative neuromonitoring (IONM) techniques have evolved over the past decade into intermittent IONM (I-IONM) and continuous IONM (C-IONM) modes of application. Despite many prior publications on both types of IONM, there remains uncertainty about what outcomes should be measured for each form of IONM. The primary objective of this paper is to define categories of benefit for I-IONM/C-IONM and to clarify and standardize their reporting outcomes.

The short-latency R1 response of the electrical laryngeal adductor reflex contributes to airway protection by initiating glottic closure.

Objective: The fundamental role of the short-latency (R1) laryngeal adductor reflex (LAR) response remains unclear with conflicting reports in the literature. This study's primary aim was to objectively determine whether the bilateral R1 response, which was elicited by electrical stimulation of the supraglottic mucosa, triggered bilateral glottis closure.

Methods: Video recording of the LAR in a prospective case series of patients undergoing trans-oral rigid laryngoscopy.

Optimizing the methodology for saphenous nerve somatosensory evoked potentials for monitoring upper lumbar roots and femoral nerve during lumbar spine surgery: technical note.

The demand for intraoperative monitoring (IOM) of lumbar spine surgeries has escalated to accommodate more challenging surgical approaches to prevent perioperative neurologic deficits. Identifying impending injury of individual lumbar roots can be done by assessing free-running EMG and by monitoring the integrity of sensory and motor fibers within the roots by eliciting somatosensory (SEP), and motor evoked potentials. However, the common nerves for eliciting lower limb SEP do not monitor the entire lumbar plexus, excluding fibers from L1 to L4 roots.

Quadriplegia, an Unusual Outcome After Anterior Cervical Discectomy and Fusion: A Case Report.

Case: A 68-year-old woman who underwent a C5 to C6 anterior cervical discectomy and fusion (ACDF) surgery presented with new-onset postoperative quadriplegia. During discectomy, intraoperative neurophysiological monitoring alerted of a spinal cord (SC) dysfunction. The surgery was halted, and measures to ensure adequate SC perfusion were initiated.

Continuous neuromonitoring during radiofrequency ablation of benign thyroid nodules provides objective evidence of laryngeal nerve safety.

Introduction: The recurrent laryngeal nerves(RLN) run immediately posterior to the thyroid capsule and could be injured during thyroid radiofrequency ablation(RFA). This study assesses whether RLN functional integrity is altered during RFA using continuous intraoperative neuromonitoring(CIONM).

Methods: Prospective case series of twenty nodules treated with RFA under general anesthesia utilizing the laryngeal adductor reflex(LAR) for CIONM.

Neurophysiological monitoring of the laryngeal adductor reflex during cerebellar-pontine angle and brainstem surgery.

Objective: To correlate intraoperative changes of the laryngeal adductor reflex (LAR), alone or in combination with corticobulbar motor evoked potential of vocal muscles (vocal-CoMEPs), with postoperative laryngeal function after posterior fossa and brainstem surgery.

Methods: We monitored 53 patients during cerebellar-pontine angle and brainstem surgeries. Vocal-CoMEPs and LAR were recorded from an endotracheal tube with imbedded electrodes or hook-wires electrodes.

Mortality risk assessment in Spain and Italy, insights of the HOPE COVID-19 registry.

Recently the coronavirus disease (COVID-19) outbreak has been declared a pandemic. Despite its aggressive extension and significant morbidity and mortality, risk factors are poorly characterized outside China. We designed a registry, HOPE COVID-19 (NCT04334291), assessing data of 1021 patients discharged (dead or alive) after COVID-19, from 23 hospitals in 4 countries, between 8 February and 1 April.

Effects of Hepatitis C Virus (HCV) Eradication on Bone Mineral Density in Human Immunodeficiency Virus/HCV-Coinfected Patients.

Background: Little is known about the effects of eradication of hepatitis C virus (HCV) on bone mineral density (BMD) and biomarkers of bone remodeling in human immunodeficiency virus (HIV)/HCV-coinfected patients.

Methods: We prospectively assessed standardized BMD (sBMD) at the lumbar spine and femoral neck, World Health Organization BMD categories at both sites, and plasma concentrations of soluble receptor activator of NF-κβ ligand (sRANKL), and osteoprotegerin (OPG) at baseline (the date of initiation of anti-HCV therapy) and at 96 weeks.

Results: A total of 238 patients were included.

Continuous Laryngeal Adductor Reflex Versus Intermittent Nerve Monitoring in Neck Endocrine Surgery.

Objective: Intraoperative neuromonitoring (IONM) techniques aim to identify and potentially prevent nerve injury during surgeries. Prior studies into the efficacy of recurrent laryngeal nerve (RLN) IONM convey mixed results, with some claiming equivalence between IONM and no monitoring at all. The goal of the current study was to compare continuous RLN monitoring using the laryngeal adductor reflex (LAR) to intermittent RLN monitoring (intermittent IONM) to determine whether continuous monitoring reduces the incidence of intraoperative RLN injury during neck endocrine surgeries.

Intraoperative Neurophysiologic Monitoring Correlates with Neurologic Outcome After Endovascular and Surgical Treatment of a Cervical Arteriovenous Malformation.

Background:  The treatment of spinal intramedullary arteriovenous malformations (AVMs) presents the risk of spinal cord ischemia because of the vascular nidus and their feeding arteries involving and supplying the spinal cord parenchyma. The multimodal approach includes endovascular embolization and microsurgical excision, both benefiting from intraoperative neurophysiologic monitoring. We present a case study of a patient who underwent several staged embolizations and open surgery for microsurgical excision.

Effects of Eradication of HCV on Cardiovascular Risk and Preclinical Atherosclerosis in HIV/HCV-Coinfected Patients.

Background: To assess the effects of eradication of hepatitis C virus (HCV) on cardiovascular risk (CVR) and preclinical atherosclerosis in HIV/HCV-coinfected patients.

Setting: Prospective cohort study.

Methods: We assessed serum lipids, 10-year Framingham CVR scores, pulse wave velocity, carotid intima-media thickness, and biomarkers of inflammation and endothelial dysfunction (BMKs) at baseline and 96 weeks (wk) after initiation of anti-HCV therapy (Rx) in HIV/HCV-coinfected patients.

Application of different thresholds for instrumentation device testing in minimally invasive lumbosacral spine fixation.

The main aim of this study was evaluating the reliability of stimulus-evoked electromyography (using different thresholds for stimulation of the instrumentation devices) for minimally invasive pedicle screw placement in the lumbosacral spine. A threshold of 5 mA was applied for the pedicle access needle. 7 mA was applied for the tapscrew and pedicle screw stimulation.

Laryngeal adductor reflex hyperexcitability may predict permanent vocal fold paralysis.

Laryngeal adductor reflex-continuous intraoperative neuromonitoring (LAR-CIONM) is a novel method of continuous intraoperative neuromonitoring. In contrast to other vagal nerve monitoring techniques, which elicit a laryngeal compound muscle action potential, LAR-CIONM elicits a laryngeal reflex response (LAR). In 300 nerves at risk monitored with LAR-CIONM, two patients have had postoperative permanent vocal fold immobility (VFI).

Mild profile improvement of immune biomarkers in HIV/HCV-coinfected patients who removed hepatitis C after HCV treatment: A prospective study.

Objective: There are a lack of consistency among articles in regards to the evolution of peripheral immune biomarkers after HCV therapy. We aimed to detect the most relevant changes in peripheral immune biomarkers among HIV/HCV-coinfected patients who achieved sustained virologic response (SVR) following peg-IFN-α/ribavirin therapy and to evaluate its normalization with respect to an HIV-monoinfected control group.

Methods: We performed a prospective cohort study in 99 HIV/HCV-coinfected patients with samples at baseline (HIV/HCV-b-group) and at week 24 after SVR (HIV/HCV-f-group).