Assessment of autonomic nervous system dysfunction associated with peripheral neuropathies in the context of clinical neurophysiology practice.

Peripheral neuropathies may involve the small diameter nerve fibers of the autonomic nervous system. In the presence of clinical signs compatible with dysautonomia, it is very difficult to affirm that these signs are really linked to an alteration in postganglionic autonomic innervation, and not to a lesion of the central nervous system or to a direct damage to the tissues and innervated organs. Also, in the context of the investigation of peripheral neuropathies, there is an interest in performing objective and quantitative assessment of distal autonomic innervation. The corresponding autonomic tests are mainly based on the exploration of sudomotor or vasomotor disorders of the limb extremities. In this article, we provide an overview of the various tests available for the study of the autonomic nervous system in clinical practice, including vasomotor reactivity tests, in particular based on laser Doppler techniques, and sudomotor tests, based on axon-reflexes produced by iontophoresis of cholinergic drugs or on the simpler measurement of electrochemical skin conductance by the Sudoscan® device.

Survey of Clinical Neurophysiology and Epilepsy Fellowship Programs in the United States During COVID-19.

PURPOSE: The COVID-19 pandemic impacted clinical practice, education, and research in Neurophysiology/Epilepsy. Although there is published literature on clinical impact, its educational impact is not well described. A national survey of Clinical Neurophysiology (CNP) and Epilepsy fellowship programs was conducted to assess the impact of COVID-19 on fellowship education. METHODS: A list of accredited Clinical Neurophysiology and Epilepsy fellowship programs was obtained from the Accreditation Council for Graduate Medical Education. Program directors at individual locations were contacted to complete a brief survey about the program and impact of COVID-19. Fellows from responding programs were subsequently invited to share their perceptions about the impact of the pandemic on their training. RESULTS: From 176 programs, 40 PDs responded (22.7%). From these 40 programs, fellows from 26 completed surveys (65.0% response). There was a reduction in EEG and epilepsy monitoring unit volumes post-COVID-19, with a trend of change for EMG, whereas continuous EEG volumes were mostly unchanged. The impact of the pandemic on training was rated as moderate to severe (≥50%) by 30.0% of PDs and 49.0% of trainees. In remarkable agreement, 20.0% of PDs and 20.4% of fellows believed that additional fellowship training was needed before graduation. Lack of fellow satisfaction was correlated with the perceived impact of the pandemic on education ( p = 0.008). CONCLUSIONS: This survey revealed a considerable impact on EEG/EMG clinical volume because of COVID-19, although continuous EEG was not as impacted. More fellows than PDs believed that training was considerably impacted by COVID-19, but a similar number thought that additional training was needed. It was unclear from this study whether the fellows' perception of educational impact was solely because of the pandemic or in addition to preexisting training deficiencies in the training programs.

Real-time Pilot Crew's Mental Workload and Arousal Assessment During Simulated Flights for Training Evaluation: a Case Study.

Training assessment is usually done by evaluating information derived from instructor's supervision related to the pilot's operational performance and behavior. However, this approach lacks objective measures, especially regarding the pilots' mental states while accomplishing the flight training tasks. The study therefore aimed at developing and testing a method for gathering and analyzing in real-time pilots' brain activity and skin conductance to improve the training evaluation. In this regard, Novice pilots' neurophysiological signals were acquired throughout multi-crew training sessions. The results demonstrated how the methodology proposed was able to endow real-time pilots' mental workload and arousal assessment for i) better evaluating training progress and operational behavior during the training session, and ii) for objectively comparing different training sessions.

The Development and Neurophysiological Assessment of Newborn Auditory Cognition: A Review of Findings and Their Application.

This review article introduces the basic principles of infants' neurophysiology, while summarizing the core knowledge of the anatomical structure of the auditory pathway, and presents previous findings on newborns' neural speech processing and suggests their possible applications for clinical practice. In order to tap into the functioning of the auditory pathway in newborns, recent approaches have employed electrophysiological techniques that measure electrical activity of the brain. The neural processing of an incoming auditory stimulus is objectively reflected by means of auditory event-related potentials. The newborn's nervous system processes the incoming sound, and the associated electrical activity of the brain is measured and extracted as components characterized by amplitude, latency, and polarity. Based on the parameters of event-related potentials, it is possible to assess the maturity of a child's brain, or to identify a pathology that needs to be treated or mitigated. For instance, in children with a cochlear implant, auditory event-related potentials are employed to evaluate an outcome of the implantation procedure and to monitor the development of hearing. Event-related potentials turn out to be an irreplaceable part of neurodevelopmental care for high-risk children e.g., preterm babies, children with learning disabilities, autism and many other risk factors.

Creating a New Set of Milestones for the Clinical Neurophysiology Fellowship.

INTRODUCTION: The Accreditation Council for Graduate Medical Education and the American Board of Psychiatry and Neurology first developed milestones for the clinical neurophysiology (CNP) fellowship in 2015. The milestones provide a comprehensive evaluation of the fellow's development based on six domains of competency. Here, we describe the development of a new set of milestones for CNP fellowship with level 1 as the incoming level, level 4 as the goal for graduation, and level 5 as the aspirational level that may not be achieved. METHODS: Committee members were nominated or volunteered to participate in the milestones update. Milestone development began with the creation of a shared mental model of the ideal skills and knowledge a graduating CNP fellow should attain. RESULTS: The CNP committee met virtually 7 times for a total of 14 meeting hours. Nine Patient Care and five Medical Knowledge milestones evolved from the seven Patient Care and six Medical Knowledge milestones that were in the first iteration. The committee incorporated 11 "Harmonized Milestones" into the revision and a supplemental guide was created. CONCLUSIONS: The revised Accreditation Council for Graduate Medical Education milestones for CNP fellowship contain important updates that program directors should review against their curricula to identify any gaps in learning. Program leadership should take note of two new Patient Care milestones for telemedicine and intraoperative monitoring. Clinical neurophysiology fellowships are not designed to provide level 4 competency across all milestones. The revised milestones should be viewed within the context of an individual program's goals.

Seventy years since the invention of the averaging technique in Neurophysiology: Tribute to George Duncan Dawson / 70 anos da invenção da técnica de promediação na Neurofisiologia: Tributo a George Duncan Dawson

ABSTRACT In 1951, the physiologist George Duncan Dawson presented his work with the averaging of the signal in the evoked potentials (EPs), opening a new stage in the development of clinical neurophysiology. The authors present aspects of Professor Dawson's biography and a review of his work on the EPs and, mainly, the article reveals the new technique in detail that would allow the growth of the clinical application of the visual, auditory, and somatosensory EPs.

RESUMO Em 1951 o fisiologista George Duncan Dawson apresentou seu trabalho com a promediação de sinal nos potenciais evocados, abrindo uma nova etapa no desenvolvimento da neurofisiologia clínica. Os autores apresentam aspectos da biografia do professor Dawson e uma revisão de seus trabalhos sobre os potenciais evocados, principalmente do artigo que mostrava a nova técnica, que viria a permitir o crescimento da aplicação clínica dos potenciais evocados visual, auditivo e somatossensitivo.

Clinical Neurophysiology Fellowship Program Directors Survey on a Standardized Fellowship Match Process: A Call for Action.

PURPOSE: To survey US Clinical Neurophysiology (CNP) fellowship program directors on the nature of CNP and related training programs, current recruitment cycle, and views for a standardized process. METHODS: A 23-question electronic survey was sent to all 93 US Accreditation Council for Graduate Medical Education-accredited CNP fellowship program directors from December 2020 to January 2021. RESULTS: The response rate was 60%. There was great variability in the number of CNP positions and CNP tracks offered. The following tracks were identified: 48% EEG dominant, 26% EMG dominant, 22% split equally between EEG and EMG, and 2% and 1% were neurophysiologic intraoperative monitoring and autonomic dominant, respectively. Of the responding institutions, 43% offered a second year of training options to CNP fellows, mainly in conjunction with Epilepsy fellowship, which was pursued by 25% of CNP fellows. Many programs indicated flexibility in their design between different CNP tracks or between CNP and other related training programs based on the available candidates. The median percentage of CNP fellowship positions filled over the last 5 years was 80%, and there was great variation in the recruitment timeline across institutions. Overall, 86% of program directors favored a universal timeline and 71% favored a formal match for CNP. The respondents were split between an independent CNP match (39%) and joining the initiatives of affiliate societies on a standardized process (61%). CONCLUSIONS: There is significant heterogeneity in the makeup of the CNP fellowship programs and the recruitment process. The majority of CNP program directors are in favor of standardization of the recruitment process.

Seventy years since the invention of the averaging technique in Neurophysiology: Tribute to George Duncan Dawson.

OBJECTIVE: In 1951, the physiologist George Duncan Dawson presented his work with the averaging of the signal in the evoked potentials (EPs), opening a new stage in the development of clinical neurophysiology. The authors present aspects of Professor Dawson's biography and a review of his work on the EPs and, mainly, the article reveals the new technique in detail that would allow the growth of the clinical application of the visual, auditory, and somatosensory EPs.

Constantin von Economo´s 90th death anniversary.

The year of 2021 marks 90 year since the death of the neuroscientist Constantin von Economo, whose research in various areas was extremely relevant for the field of neurology. He described lethargic epidemic encephalitis, published an atlas of the cytoarchitecture of the human cerebral cortex, and conducted multiple studies in neuroanatomy, neurophysiology, and clinical neurology. Von Economo's genius extended into other nonmedical fields such as aeronautics, and he had renowned artistic skills.

Constantin von Economo´s 90th death anniversary / O 90º aniversário da morte de Constantin von Economo

ABSTRACT The year of 2021 marks 90 year since the death of the neuroscientist Constantin von Economo, whose research in various areas was extremely relevant for the field of neurology. He described lethargic epidemic encephalitis, published an atlas of the cytoarchitecture of the human cerebral cortex, and conducted multiple studies in neuroanatomy, neurophysiology, and clinical neurology. Von Economo's genius extended into other nonmedical fields such as aeronautics, and he had renowned artistic skills.

RESUMO O ano de 2021 marca o 90° aniversário da morte do neurocientista Constantin von Economo, ou Constantin Freiherr (Barão) von Economo. Von Economo realizou várias pesquisas de grande relevo na área da neurologia, com a descrição da encefalite letárgica epidêmica, a publicação do atlas sobre a citoarquitetura do córtex cerebral humano, além dos seus múltiplos estudos em neuroanatomia, neurofisiologia, bem como na neurologia clínica. A genialidade de von Economo se estendeu para outras áreas não médicas, com o seu grande interesse em aeronáutica, como piloto de avião, além dos seus reconhecidos dotes artísticos.

Neurophysiological assessment of brachioradial pruritus patients.

BACKGROUND: Pruritus is a common complaint in dermatology. Wartenberg, in 1943, associated pruritus with neuropathy, relating it to the "posterior antebrachial cutaneous nerve neuropathy". In 1968, Waisman described patients with frequent pruritus complaints in the upper limb during the summer, which he named "brachioradial summer pruritus". Currently, this pruritus is named brachioradial pruritus (BRP). BRP is characterized by a chronic pruritus, usually localized, with a long duration, and without apparent cutaneous abnormalities. Neurological disorders both from the central and peripheral nervous systems, including multiple sclerosis, are associated with pruritus. OBJECTIVE: To investigate correlations between symptomatic dermatomes and alterations in the myotomes, as evidenced by electroneuromyography (ENMG). METHODS: Forty-six patients with BRP dermatological diagnoses were subjected to upper limb ENMG. RESULTS: Among 46 patients with C5 to C8 dermatomal pruritus, we evaluated 113 symptomatic dermatomal areas. Overall, 39 (85%) patients had radicular involvement and 28 (60%) had agreement between complaint and the ENMG findings (p=0.015). A total of 80% of the patients with complaints at C7 and 47% at C6 had radicular involvement at the same level. CONCLUSIONS: Among the patients who presented complaints, 47 and 80%, respectively, had ENMG alterations in the C6 and C7 myotomes. We conclude that peripheral nervous system involvement is associated with BRP.

Evaluación del desarrollo de la asignatura virtual Fisiología II en la especialidad Neurofisiología Clínica / Assessment of developing Physiology II as a virtual subject in the specialty of Clinical Neurophysiology

Introducción: La enseñanza mediante la modalidad virtual se adoptó como medida preventiva ante la propagación de la COVID-19. Para la educación médica cubana ha implicado un reto en cuanto a la reorganización de los programas de estudio. Con este propósito, se rediseño e implementó la asignatura Fisiología II en modalidad virtual, para garantizar la continuidad en la formación de residentes en Neurofisiología Clínica. Objetivo: Evaluar el desarrollo de la asignatura Fisiología II en su modalidad virtual desde la perspectiva de los estudiantes de la especialidad Neurofisiología Clínica. Métodos: Estudio exploratorio, no experimental y transversal. Mediante un cuestionario de preguntas cerradas y una abierta (aspectos positivos y negativos), se evaluó el desarrollo de la asignatura en modalidad virtual en relación con las variables: programa de la asignatura, desempeño de los profesores, escenario de las plataformas y soporte tecnológico. Resultados: La asignatura Fisiología II en modalidad virtual tuvo una alta aceptación por parte de los estudiantes. Los aspectos identificados como positivos fueron los relacionados con la gestión personal del tiempo, y la aplicabilidad y estructura de la asignatura; mientras que los negativos se orientaron hacia problemas de conectividad de internet y el entorno de estudio. Conclusiones: Las exitosas experiencias obtenidas en el desarrollo de la asignatura virtual Fisiología II sientan las bases para el empleo de este tipo de diseño en la especialidad de Neurofisiología Clínica y la posibilidad de extenderlo a otras asignaturas del plan de estudio(AU)

Introduction: Teaching through virtual modality was adopted as a preventive measure against the COVID-19 spread. For Cuban medical education, it has implied a challenge regarding the reorganization of study programs. For this purpose, the subject Physiology II was redesigned and implemented in virtual modality, in order to guarantee continuity in the training of Clinical Neurophysiology residents. Objective: To assess the development of the subject Physiology II in its virtual modality from the perspective of the students of the Clinical Neurophysiology specialty. Methods: Exploratory, nonexperimental and cross-sectional study. Through a questionnaire made up of closed questions and one open question (positive and negative aspects), the development of the subject in virtual modality was assessed in relation to the variables subject syllabus, professors' performance, platform scenario, and technological support. Results: The subject Physiology II in virtual modality had a high acceptance by the students. The aspects identified as positive were those related to individual time management, as well as the subject's applicability and structure; while the negative ones were oriented towards internet connectivity problems and the study environment. Conclusions: The successful experiences obtained in the development of Physiology II as a virtual subject lay the foundations for using this type of design in the specialty of Clinical Neurophysiology and the possibility of extending it to other subjects of the study plan(AU)

Importance of access to epilepsy monitoring units during the COVID-19 pandemic: Consensus statement of the International League against epilepsy and the International Federation of Clinical Neurophysiology.

Restructuring of healthcare services during the COVID-19 pandemic has led to lockdown of Epilepsy Monitoring Units (EMUs) in many hospitals. The ad-hoc taskforce of the International League Against Epilepsy (ILAE) and the International Federation of Clinical Neurophysiology (IFCN) highlights the detrimental effect of postponing video-EEG monitoring of patients with epilepsy and other paroxysmal events. The taskforce calls for action to continue functioning of Epilepsy Monitoring Units during emergency situations, such as the COVID-19 pandemic. Long-term video-EEG monitoring is an essential diagnostic service. Access to video-EEG monitoring of the patients in the EMUs must be given high priority. Patients should be screened for COVID-19, before admission, according to the local regulations. Local policies for COVID-19 infection control should be adhered to during the video-EEG monitoring. In cases of differential diagnosis where reduction of antiseizure medication is not required, consider home video-EEG monitoring as an alternative in selected patients.

[Neurophysiological methods in the assessment of different forms of migraine]. / Neirofiziologicheskie metody otsenki razlichnykh form migreni.

The review considers the efficacy of neurophysiological methods for the study of migraine. According to many authors, such neurophysiological methods as analysis of visual and somatosensory evoked potentials, trigeminal evoked potentials are informative for assessing the functional state of trigeminocervical and sensory systems. Analysis of bioelectric activity of the brain is used for differential diagnosis of migraine and epilepsy, evaluation of various forms and types of migraine. Studies with recording and analysis of laser evoked potentials, as well as the effects of transcranial magnetic stimulation, both diagnostic and non-pharmacological rehabilitation effects on pain syndrome, which increases the efficiency and quality of life in migraine, are considered.

Cost-Reducing Traits for Agonistic Head Collisions: A Case for Neurophysiology.

Many animal species have evolved extreme behaviors requiring them to engage in repeated high-impact collisions. These behaviors include mating displays like headbutting in sheep and drumming in woodpeckers. To our knowledge, these taxa do not experience any notable acute head trauma, even though the deceleration forces would cause traumatic brain injury in most animals. Previous research has focused on skeletomuscular morphology, biomechanics, and material properties in an attempt to explain how animals moderate these high-impact forces. However, many of these behaviors are understudied, and most morphological or computational studies make assumptions about the behavior without accounting for the physiology of an organism. Studying neurophysiological and immune adaptations that covary with these behaviors can highlight unique or synergistic solutions to seemingly deleterious behavioral displays. Here, we argue that selection for repeated, high-impact head collisions may rely on a suite of coadaptations in intracranial physiology as a cost-reducing mechanism. We propose that there are three physiological systems that could mitigate the effects of repeated head trauma: (1) the innate neuroimmune response; (2) the glymphatic system, and (3) the choroid plexus. These systems are interconnected yet can evolve in an independent manner. We then briefly describe the function of these systems, their role in head trauma, and research that has examined how these systems may evolve to help reduce the cost of repeated, forceful head impacts. Ultimately, we note that little is known about cost-reducing intracranial mechanisms making it a novel field of comparative study that is ripe for exploration.

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.

La neuroanatomía y neurofisiología en la comprensión de los trastornos del espectro autista / Neuroanatomy and neurophysiology in the study of autism spectrum disorders

Introducción: Los trastornos de espectro autista se caracterizan por presentar un déficit en la interacción y comunicación social con presencia de patrones repetitivos y restrictivos de comportamiento, intereses y actividades. En ellos estarían implicadas causas genéticas, ambientales y del desarrollo del sistema nervioso central. Un mayor conocimiento de la neuroanatomía y la neurofisiología ayudaría a comprender mejor este trastorno del neurodesarrollo. Objetivo: Profundizar en el conocimiento neuroanatómico y neurofisiológico de los trastornos del espectro autista. Métodos: Se realizó una búsqueda bibliográfica acerca del tema en las bases de datos LILACS, Scopus, SciELO, Pubmed, Medigraphic. Se escogieron 13 documentos, todos correspondientes a artículos originales que abordan el tema desde diferentes aristas. De los documentos, dos fueron localizados en Scopus, uno en Pubmed, cuatro en Medigrafhic, dos en LILACS y cuatro en SciELO. Resultados: Los trastornos de espectro autista se producen por una alteración estructural y funcional de la corteza cerebral. Los estudios de neuroimágenes han demostrado las alteraciones estructurales, fundamentalmente en la corteza prefrontal y sus conexiones, principal región encefálica implicada en la regulación de la conducta social. Las técnicas de secuenciación genómica de nueva generación muestran el origen genético en casos donde los estudios previamente señalados han resultado ser normales. Conclusiones: La profundización del conocimiento neuroanatómico y neurofisiológico de los trastornos de espectro autista permiten comprenderlos mejor(AU)

Introduction: Autism spectrum disorders are characterized by social deficits and communication difficulties, as well as restrictive, repetitive behavior patterns, interests and activities. Their causes may be genetic, environmental or related to the development of the central nervous system. Broader knowledge about neuroanatomy and neurophysiology could lead to a better understanding of this neurodevelopmental disorder. Objective: Gain insight into the neuroanatomy and neurophysiology of autism spectrum disorders. Methods: A bibliographic search about the topic was conducted in the databases LILACS, Scopus, SciELO, Pubmed and Medigraphic. A total 13 documents were selected, all of which were original papers approaching the topic from different perspectives. Two of the documents were obtained from Scopus, one from Pubmed, four from Medigraphic, two from LILACS and four from SciELO. Results: Autism spectrum disorders are caused by a structural and functional alteration of the cerebral cortex. Neuroimaging studies have shown the structural alterations, which mainly occur in the prefrontal cortex and its connections, the principal encephalic region involved in social behavior regulation. New generation genomic sequencing techniques reveal a genetic origin in cases where previous studies have been normal. Conclusions: Broader knowledge about the neuroanatomy and neurophysiology of autism spectrum disorders lead to their better understanding(AU)

Electrodiagnostic assessment of the autonomic nervous system: A consensus statement endorsed by the American Autonomic Society, American Academy of Neurology, and the International Federation of Clinical Neurophysiology.

Evaluation of disorders of the autonomic nervous system is both an art and a science, calling upon the physician's most astute clinical skills as well as knowledge of autonomic neurology and physiology. Over the last three decades, the development of noninvasive clinical tests that assess the function of autonomic nerves, the validation and standardization of these tests, and the growth of a large body of literature characterizing test results in patients with autonomic disorders have equipped clinical practice further with a valuable set of objective tools to assist diagnosis and prognosis. This review, based on current evidence, outlines an international expert consensus set of recommendations to guide clinical electrodiagnostic autonomic testing. Grading and localization of autonomic deficits incorporates scores from sympathetic cardiovascular adrenergic, parasympathetic cardiovagal, and sudomotor testing, as no single test alone is sufficient to diagnose the degree or distribution of autonomic failure. The composite autonomic severity score (CASS) is a useful score of autonomic failure that is normalized for age and gender. Valid indications for autonomic testing include generalized autonomic failure, regional or selective system syndromes of autonomic impairment, peripheral autonomic neuropathy and ganglionopathy, small fiber neuropathy, orthostatic hypotension, orthostatic intolerance, syncope, neurodegenerative disorders, autonomic hyperactivity, and anhidrosis.

Basic guide to chronic pain assessment: from neurophysiology to bedside.

Chronic musculoskeletal pain is a highly prevalent condition that is commonly encountered in both general and specialist practice. Nonetheless, it still represents a significant challenge to the practitioners because of the lack of substantial evidence-based guidance. This review aimed to summarize the main pathophysiological mechanisms of chronic pain offering a mechanism-oriented approach to diagnosis and management. We believe that a basic knowledge of the physical signs and symptoms of these mechanisms could empower the clinician to choose appropriate medication and identify high-risk pain patients. Central sensitization and neuropathic features may arise in previously nociceptive and inflammatory pain syndromes. Central sensitization is a functional remodeling of the spinal cord, where light touch afferents are recruited by nociceptive second-order neurons. Neuropathic features include both negative signs, such as reduced perception of vibration and touch, and positive symptoms, such as paroxysmal electric shock pain, due to ectopic discharge. These phenomena are the neurobiological basis of the commonly defined refractory chronic pain. Early detection and specific treatment of these mechanisms are required in order to restrain the reinforcement of pronociceptive remodeling of the nervous system.