Intraoperative neuromonitoring in Chiari I malformation surgery: a systematic review and meta-analysis.

Chiari Malformation Type I (CMI) is a prevalent neurosurgical condition characterized by the descent of cerebellar tonsils below the foramen magnum. Surgery, aimed at reducing symptomatology and syrinx size, presents risks, making intraoperative neuromonitoring (IONM) a potentially vital tool. Despite its widespread use in cervical spine surgery, the utility of IONM in CMI surgery remains controversial, with concerns over increased operative time, cost, restricted anesthetic techniques and tongue lacerations. This systematic review and meta-analysis followed the Cochrane Group standards and PRISMA framework. It encompassed an extensive search through PubMed, Embase, and Web of Science up to December 2023, focusing on clinical and surgical outcomes of IONM in CMI surgery. Primary outcomes included the use of various IONM techniques, complication rates, clinical improvement, reoperation, and mortality. The review, registered at PROSPERO (CRD42024498996), included both prospective and retrospective studies, with rigorous selection and data extraction processes. Statistical analysis was conducted using R software. The review included 16 studies, comprising 1358 patients. It revealed that IONM techniques predominantly involved somatosensory evoked potentials (SSEPs), followed by motor evoked potentials (MEPs) and Brainstem auditory evoked potentials (BAEPs). The estimated risk of complications with IONM was 6% (95% CI: 2-11%; I2 = 89%), lower than previously reported rates without IONM. Notably, the clinical improvement rate post-surgery was high at 99% (95% CI: 98-100%; I2 = 56%). The analysis also showed lower reoperation rates in surgeries with IONM compared to those without. Interestingly, no mortality was observed in the included studies. This systematic review and meta-analysis indicate that intraoperative neuromonitoring in Chiari I malformation surgery is associated with favorable clinical outcomes, including lower complication and reoperation rates, and high rates of clinical improvement.

A Concise Guide to D-Wave Monitoring during Intramedullary Spinal Cord Tumour Surgery.

D-waves (also called direct waves) result from the direct activation of fast-conducting, thickly myelinated corticospinal tract (CST) fibres after a single electrical stimulus. During intraoperative neurophysiological monitoring, D-waves are used to assess the long-term motor outcomes of patients undergoing surgery for intramedullary spinal cord tumours, selected cases of intradural extramedullary tumours and surgery for syringomyelia. In the present manuscript, we discuss D-wave monitoring and its role as a tool for monitoring the CST during spinal cord surgery. We describe the neurophysiological background and provide some recommendations for recording and stimulation, as well as possible future perspectives. Further, we introduce the concept of anti D-wave and present an illustrative case with successful recordings.

Role of Intraoperative Neuromonitoring to Predict Postoperative Delirium in Cardiovascular Surgery.

OBJECTIVE: Postoperative delirium (POD) can occur in up to 50% of older patients undergoing cardiovascular surgery, resulting in hospitalization and significant morbidity and mortality. This study aimed to determine whether intraoperative neurophysiologic monitoring (IONM) modalities can be used to predict delirium in patients undergoing cardiovascular surgery. DESIGN: Adult patients undergoing cardiovascular surgery with IONM between 2019 and 2021 were reviewed retrospectively. Delirium was assessed multiple times using the Intensive Care Delirium Screening Checklist (ICDSC). Patients with an ICDSC score ≥4 were considered to have POD. Significant IONM changes were evaluated based on a visual review of electroencephalography (EEG) and somatosensory evoked potentials data and documentation of significant changes during surgery. SETTING: University of Pittsburgh Medical Center hospitals. PARTICIPANTS: Patients 18 years old and older undergoing cardiovascular surgery with IONM monitoring. MEASUREMENTS AND MAIN RESULTS: Of the 578 patients undergoing cardiovascular surgery with IONM, 126 had POD (21.8%). Significant IONM changes were noted in 134 patients, of whom 49 patients had delirium (36.6%). In contrast, 444 patients had no IONM changes during surgery, of whom 77 (17.3%) patients had POD. Upon multivariate analysis, IONM changes were associated with POD (odds ratio 2.12; 95% CI 1.31-3.44; p < 0.001). Additionally, baseline EEG abnormalities were associated with POD (p = 0.002). CONCLUSION: Significant IONM changes are associated with an increased risk of POD in patients undergoing cardiovascular surgery. These findings offer a basis for future research and analysis of EEG and somatosensory evoked potential monitoring to predict, detect, and prevent POD.

Monitorização Intraoperatória Neurofisiológica para pacientes com tumor cerebelopontino submetidos à cirurgia de exérese tumoral com alto risco de sequelas neurológicas / Neurophysiological Intraoperative Monitoring for patients with cerebellopontine tumor undergoing tumor excision surgery with high risk of neurological sequelae

INTRODUÇÃO: O ângulo ponto-cerebelar (APC) está localizado na fossa posterior cerebral e tumores que crescem nessa região podem ter um impacto significativo na função sensorial e motora. O tratamento dos TAPC consiste na ressecção cirúrgica. A MION tem como objetivo a identificação e prevenção de danos neurológicos, utilizando sinais neurofisiológicos durante o procedimento cirúrgico. PERGUNTA DE PESQUISA (PICO): A MION para pacientes com TAPC submetidos à cirurgia de exérese tumoral com alto risco de sequelas neurológicas reduz as complicações cirúrgicas, em comparação a não realização de monitorização neurofisiológica intraoperatória, sem produzir efeitos adversos ou riscos inaceitáveis na população com monitorização? EVIDÊNCIAS CLÍNICAS: Foram incluídos 22 estudos observacionais nesta síntese de evidências. Em relação aos desfechos primários, nenhum estudo avaliou sobrevida global, entretanto três estudos descreveram baixa mortalidade; vinte e um estudos apresentaram resultados para a ocorrência de déficits neurológicos novos, sendo que a maioria (n=9) descreveu a utilização de mais de uma técnica de MION simultaneamente. Em relação aos desfechos secundários, doze estudos apresentaram resultados para a possibilidade de ressecção mais ampla, sendo que a maioria utilizou a técnica Eletroneuromiografia (ENMG) (4 estudos) e a Monitorização intraoperatória neurofisiológica multimodal (MIONMm), também com 4 estudos. Os resultados dos estudos avaliados sugerem que a MION pode reduzir a ocorrência de déficits neurológicos novos e aumentar a possibilidade de ressecção mais ampla dos TAPC. Apesar de não ter sido avaliado como desfecho primário nos estudos incluídos, os aspectos de segurança detalhados não descrevem efeitos adversos significativos em relação à tecnologia. A certeza no corpo de evidências foi considerada muito baixa para os desfechos de eficácia e moderada para os desfechos de segurança. AVALIAÇÃO ECONÔMICA: Os dados da literatura sobre MION são bastante heterogêneos. De acordo com a análise de custo-efetividade empreendida, na monitorização da funcionalidade do nervo auditivo, houve um incremento na efetividade com a utilização da MION em cerca de 0,088, associada a um incremento em custos de mais de 4 mil reais. A RCEI foi de aproximadamente R$ 47 mil, em comparação à não-realização da MION. ANÁLISE DE IMPACTO ORÇAMENTÁRIO (AIO): foi feita uma avaliação do impacto orçamentário da possível incorporação da MION ao longo de 5 anos, conforme as Diretrizes Metodológicas de análise de Impacto Orçamentário, do Ministério da Saúde. A AIO com a realização da MION ao longo de 5 anos (sem custos evitados) indicou um valor de cerca de 10,6 milhões de reais, já com custos evitados este valor caiu para aproximadamente R$ 10,1 milhões. Adicionalmente os custos com aquisição dos equipamentos necessários seriam relevantes: cerca de R$ 71 milhões para a compra de 172 equipamentos de MIONMm, a serem instalados nos estabelecimentos SUS que realizam neurocirurgia. No total o dispêndio em 5 anos seria de mais de 81 milhões de reais. MONITORAMENTO DO HORIZONTE TECNOLÓGICO: Foram realizadas buscas estruturadas nas bases de dados ClinicalTrials.gov e Cortellis™ nos dias 28/08/2023 e 01/09/2023 para a localização de outros dispositivos médicos utilizados para a MION de pacientes com tumor cerebelopontino, submetidos à cirurgia de exérese tumoral com alto risco de sequelas. Na busca, foi encontrado apenas um estudo sobre um dispositivo WISE Cortical Strip (WCS), aprovado no FDA ­ U.S. Food and Drug Administration e sem registro na Anvisa ­ Agência Nacional de Vigilância Sanitária. CONSIDERAÇÕES FINAIS: Limitações importantes impedem conclusões robustas acerca do tema avaliado. Entre elas estão: (1) a inclusão de estudos sem comparador, devido à escassez de evidências; (2) diferentes técnicas de monitorização podem ser utilizadas, conforme o tipo e a localização do tumor, dificultando uma comparação direta entre essas técnicas. A certeza de evidência para os desfechos de eficácia foi considerada muito baixa, devido às limitações metodológicas e imprecisão dos estudos incluídos. Contudo, com certeza da evidência moderada, as diferentes técnicas de monitorização parecem ser seguras nesses tumores avaliados. Em relação à análise econômica, um dos aspectos marcantes foi a heterogeneidade das informações. Em relação às análises de custo efetividade realizadas, observaram-se ganhos em efetividade, a partir da adoção da MION, ainda que pequenos. Sobre a AIO, a utilização da MION ao longo de 5 anos indicou valores que podem ser considerados elevados no contexto do SUS. Por outro lado, a aquisição do equipamento para realização da MION, para os possíveis centros que realizam neurocirurgia no SUS (cerca de 170) resultaria num custo bastante elevado, sendo que aspectos como dispêndio com manutenção, não foram computados nesta análise. Por fim, a partir dos resultados dos estudos sabe-se que a MION permite uma melhor orientação do neurocirurgião durante a ressecção de TAPC e redução da morbidade cirúrgica, possibilitando a identificação e preservação de estruturas de importância, especialmente a função facial e auditiva no período pós-operatório a longo prazo. Entende-se que a escolha da técnica depende do quadro clínico do paciente, do tamanho e da localização tumoral, devendo ser uma decisão tomada em conjunto entre neurocirurgião e neurofisiologista. Apesar da possibilidade de redução de danos neurológicos ter o potencial de impactar em menores sequelas, melhor qualidade de vida e maior tempo de vida produtiva, entende-se que a implementação dessa tecnologia implicará em questões logísticas de onde ela estará disponível, assim como a necessidade de profissionais altamente habilitados para sua utilização. RECOMENDAÇÃO PRELIMINAR DA CONITEC: Na 123ª Reunião Ordinária da Conitec, realizada em 05 de outubro de 2023, os membros presentes no Comitê de Produtos e Procedimentos deliberaram que a matéria fosse disponibilizada em consulta pública com recomendação preliminar desfavorável à incorporação da MION em cirurgias de exérese de tumor de ângulo pontocerebelar (TAPC) com alto risco de sequelas neurológicas. Para essa recomendação, a Conitec considerou que a MION é eficaz e segura; porém, apesar de os custos decorrentes de sua incorporação serem elevados, o dimensionamento desses custos ainda é incerto. Ademais, foi considerado também que a técnica pode ser usada em outras situações, com possibilidade de indicação mais ampla, situação essa que enseja a necessidade de informações adicionais. CONSULTA PÚBLICA: A consulta pública n° 49 ficou vigente no período entre 24/11/2023 e 13/12/2023. Foram recebidas cinco contribuições pelo formulário para contribuições sobre experiência ou opinião de pacientes, familiares, amigos ou cuidadores de pacientes, profissionais de saúde ou pessoas interessadas no tema. Todas as contribuições (n=5; 100%) não concordaram com a recomendação preliminar da Conitec e foram favoráveis a incorporar a MION em cirurgias de exérese de TAPC com alto risco de sequelas neurológicas no SUS; no entanto, duas dessas contribuições claramente se referiam à vacina da dengue e não à MION. A consulta pública não adicionou elementos que alterassem o conteúdo deste relatório de recomendação. RECOMENDAÇÃO FINAL DA CONITEC: Na 127ª Reunião Ordinária da Conitec, realizada em 08 de março de 2024, os membros presentes no Comitê de Produtos e Procedimentos deliberaram, por unanimidade, recomendar a incorporação da monitorização intraoperatória neurofisiológica para pacientes com tumor cerebelopontino submetidos à cirurgia de exérese tumoral com alto risco de sequelas neurológicas. Após os esclarecimentos feitos pelas especialistas e a apresentação das contribuições de consulta pública, o Comitê entendeu que existe uma necessidade médica não atendida, considerou que MION é uma técnica eficaz e segura e apresenta benefícios clínicos claros à população de interesse. Apesar de o impacto orçamentário ter sido considerado elevado, esses custos foram considerados superestimados devido às limitações no levantamento dos custos para a análise. Foi assinado o Registro de Deliberação nº 884/2024. DECISÃO: incorporar, no âmbito do Sistema Único de Saúde - SUS, a monitorização intraoperatória neurofisiológica para pacientes com tumor cerebelopontino submetidos à cirurgia de exérese tumoral com alto risco de sequelas neurológicas, publicada no Diário Oficial da União nº 77, seção 1, página 176, em 22 de abril de 2024.

Eficacia y seguridad del equipo de monitoreo neurofisiológico y mapeo intraoperatorio en pacientes sometidos a neurocirugía funcional del cerebro o neurocirugía de lesiones en áreas elocuentes / Evaluation of the efficacy and safety of mechanical thrombectomy with retrievable stent in patients with acute ischemic stroke who meet the criteria for mechanical thrombectomy but are not eligible for intravenous treatment with alteplase

ANTECEDENTES: El presente documento de evaluación de tecnología sanitaria (ETS) expone el análisis de la eficacia y seguridad del equipo de monitoreo neurofisiológico intraoperatorio (EMNIO) en pacientes sometidos a neurocirugía funcional del cerebro o neurocirugía de esiones en áreas elocuentes. ediante la Nota N° 1547-GRPR-2021, el Servicio de Neurocirugía Funcional del Departamento de Neurocirugía del Hospital Nacional Edgardo Rebagliati Martins (HNERM), a través de la Gerencia de la Red Prestacional Rebagliati, solicita al Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI) la incorporación del EMNIO al petitorio de equipos biomédicos de EsSalud. El documento menciona que este equipo biomédico permitiría evaluar las funciones neurológicas motoras, sensitivas y del lenguaje, así como la actividad eléctrica cerebral, durante la neurocirugía funcional o durante la cirugía que involucra zonas altamente elocuentes del cerebro. ASPECTOS GENERALES: Existen trastornos neurológicos en los que el paciente exhibe una falta de equilibrio funcional que se traduce en una sintomatología incapacitante que no responde a tratamiento médico. La neurocirugía funcional es la rama de la neurocirugía que tiene como objetivo recuperar la función perdida o restaurar la función alterada debido a estos trastornos, los cuales no necesariamente presentan una anomalía anatómica visible (Dube 2017). Así, la neurocirugía funcional del cerebro consiste en identificar e intervenir precisamente las estructuras anatómicas presuntamente involucradas para modular la función neurológica a fin de mejorar los síntomas y la calidad de vida de los pacientes (Raslan and Viswanathan 2019). Algunas condiciones que pueden requerir de este tipo de intervención son: epilepsia refractaria; trastornos del movimiento, como la enfermedad de Parkinson; dolor crónico, entre otros (Zrinzo 2012; Raslan and Viswanathan 2019). TECNOLOGÍA SANITARIA DE INTERÉS: El mecanismo de acción de la tecnología solicitada puede dividirse en dos grandes categorías desde el punto de vista de su utilidad clínico-quirúrgica: técnicas de monitorización y técnicas de mapeo (de Quintana-Schmidt et al. 2018; Jameson, Janik, nd Sloan 2007; Shils and Sloan 2015). Las técnicas de monitorización permiten el registro de las respuestas neurofisiológicas de forma continua durante el acto quirúrgico, sin necesidad de la intervención del neurocirujano. Las técnicas de mapeo permiten la identificación, localización y evaluación funcional de una estructura nerviosa particular (Shils and Sloan 2015). METODOLOGÍA: Se realizó una búsqueda sistemática de literatura científica a fin de identificar la mejor evidencia disponible en mayo del 2022, la cual fue complementada con una actualización en bases de datos hasta marzo del 2023 con el objetivo de identificar documentos sobre la eficacia y seguridad del EMNIO en pacientes sometidos a neurocirugía funcional del cerebro o neurocirugía de lesiones localizadas en áreas elocuentes. Así, con base en la pregunta PICO (Tabla 1), se formuló una estrategia de búsqueda especializada (Material Suplementario) para consultar las siguientes bases . de datos: PubMed, Cochrane Library, Web of Science y LILACS (Literatura >1°1 Latinoamericana y del Caribe en Ciencias de la Salud). to* La búsqueda sistemática fue suplementada con una búsqueda manual en la lista de referencias bibliográficas de los estudios incluidos en esta ETS. Además, se realizó una búsqueda manual en el buscador de Google, a fin de poder identificar guías de práctica clínica (GPC) y ETS de relevancia que pudiesen haber sido omitidas por la estrategia de búsqueda o que no hayan sido publicadas en las bases de datos consideradas. Asimismo, se realizó una búsqueda bibliográfica dentro de las bases de datos pertenecientes a grupos académicos o gubernamentales que realizan GPC y ETS. Estas bases de datos fueron las del National Institute for Health and Care Excellence (NICE), de la Canadian Agency for Drugs and Technologies in Health (CADTH) y de la Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas (BRISA). Además, se consultaron páginas web de sociedades especializadas en neurocirugía, como: American Association of Neurologic Surgeons (AANS), The American Clinical Neurophysiology Society, Congress of Neurologic Surgeons (CNS), American Society of Neurophysiological Monitoring y European Association of Neuro-Oncology (EANO). Por último, se realizó una búsqueda de estudios clínicos en ejecución o aún no terminados en las plataformas ClinicalTrials.gov e International Clinical Trial Registry Platform (ICTRP). RESULTADOS: Se identificaron 309 estudios a partir de la búsqueda bibliográfica sistemática en bases de datos. Luego de eliminar duplicados, 293 fueron elegibles para tamizaje por título y resumen con el aplicativo web Rayyan. Así, se obtuvieron ocho estudios elegibles para la evaluación a texto completo. Por otra parte, como producto de la búsqueda manual, se obtuvieron 15 estudios candidatos para revisión a texto completo. De esta manera, se revisaron 23 artículos a texto completo, de los cuales ocho fueron considerados elegibles para inclusión en esta ETS. CONCLUSIONES: El presente dictamen preliminar expone una síntesis de la mejor evidencia disponible a la fecha (20 de marzo del 2023) sobre la eficacia y seguridad del EMNIO en pacientes sometidos a neurocirugía funcional del cerebro o neurocirugía en áreas elocuentes en comparación con las técnicas neuroquirúrgicas convencionales disponibles en EsSalud. Actualmente, en EsSalud los procedimientos de neurocirugía funcional del cerebro y neurocirugía de lesiones en áreas elocuentes se realizan con técnicas convencionales y tecnologías como el microscopio quirúrgico de neurocirugía, equipo electroencefalógrafo portátil y el equipo electromiógrafo y potenciales evocados. El cuerpo de evidencia comprendió cirugías de schwannoma vestibular, glioma de bajo grado y aneurisma no roto. No se encontraron estudios ni GPC relacionadas al uso del EMNIO en neurocirugía funcional del cerebro. Los artículos encontrados que respondieron la pregunta PICO fueron tres GPC, dos RS con MA y un estudio observacional. Las tres GPC recomiendan de forma débil el uso del EMNIO para cirugías de schwannoma vestibular y glioma de bajo grado. Sin embargo, estas recomendaciones no solo tienen sustento en estudios observacionales retrospectivos de muy bajo nivel metodológico, sino que la evidencia que las informa tiene resultados contradictorios respecto a la preservación de la funcionalidad neurológica. Cuando se trata de sobrevida global, el único estudio que evaluó este desenlace reporta que, a un seguimiento de cinco años, no se encontraron diferencias significativas entre los pacientes con gliomas de bajo grado intervenidos con EMNIO y aquellos intervenidos sin la tecnologia. En cuanto al perfil de eficacia, los resultados son inconsistentes. En algunas cirugías el EMNIO se asoció a menor ocurrencia de déficits neurológicos postoperatorios (Nasi et al. 2020), mientras que en otras se observó que se asociaba a una significativa mayor ocurrencia (De Witt Hamer et al. 2012). Con relación a los déficits neurológicos tardíos o permanentes, en algunos estudios no se reportaron diferencias significativas entre usar y no usar EMNIO (Nasi et al. 2020) pero en otros estudios, se reporta una significativa menor ocurrencia en los pacientes que fueron intervenidos con EMNIO (Park et al. 2021; De Witt Hamer et al. 2012). Además, en cirugías de pacientes con tumores cerebrales, el uso de EMNIO no ha mostrado un beneficio clínico adicional en términos de sobrevida global en comparación con no usarlo (Chang et al. 2011). Por otro lado, la evaluación del EMNIO como herramienta pronóstica no responde a la intención de uso propuesta, ya que se espera que las alertas que dan a conocer una anomalia. El perfil de seguridad de esta tecnología no ha sido evaluado en ningún estudio encontrado a la fecha para la población de interés. Ello no permite estimar su balance riesgo beneficio. Además, genera preocupaciones ya que se cuenta con evidencia preliminar de reportes de eventos adversos asociados al uso de EMNIO como convulsiones, hemorragias, quemaduras, entre otros (David B. MacDonald 2002; Ulkatan et al. 2017; Szelényi, Joksimovic, and Seifert 2007; Zrinzo et al. 2012). Finalmente, no se cuenta con evidencia comparativa de eficacia ni seguridad del EMNIO en neurocirugía funcional del cerebro, por lo que el balance riesgo beneficio de esta tecnología tampoco es evaluable en este contexto. Siendo que el principal objetivo de la neurocirugía funcional del cerebro es restaurar una función perdida e incrementar la calidad de vida, resulta especialmente necesario contar con una evaluación rigurosa de desenlaces de seguridad relevantes para el paciente. De este modo, se concluye que existe incertidumbre acerca del perfil de eficacia del EMNIO y un vacío de información acerca de su perfil de seguridad por lo que, el balance riesgo beneficio de esta tecnología es incierto. En consecuencia, a la fecha, no hay razones técnicas para esperar que el EMNIO pueda mejorar la sobrevida, la calidad de vida, o cualquiera de los otros desenlaces de relevancia para los pacientes mencionados en la pregunta PICO. Por lo tanto, el IETSI no aprueba el uso del equipo de monitoreo neurofisiológico y mapeo intraoperatorio en pacientes sometidos a neurocirugía funcional del cerebro o neurocirugía de lesiones en áreas elocuentes.

Transcranial electric stimulation motor evoked potentials for cervical spine intraoperative monitoring complications: systematic review and illustrative case of cardiac arrest.

PURPOSE: We show a systematic review of known complications during intraoperative neuromonitoring (IONM) using transcranial electric stimulation motor evoked potentials (TES-MEP) on cervical spine surgery, which provides a summary of the main findings. A rare complication during this procedure, cardiac arrest by cardioinhibitory reflex, is also described. METHODS: Findings of 523 scientific papers published from 1995 onwards were reviewed in the following databases: CENTRAL, Cochrane Library, Embase, Google Scholar, Ovid, LILACS, PubMed, and Web of Science. This study evaluated only complications on cervical spine surgery undergoing TES-MEP IONM. RESULTS: The review of the literature yielded 13 studies on the complications of TES-MEP IONM, from which three were excluded. Five studies are case series; the rest are case reports. Overall, 169 complications on 167 patients were reported in a total of 38,915 patients, a global prevalence of 0.43%. The most common complication was tongue-bite in 129 cases, (76.3% of all complication events). Tongue-bite had a prevalence of 0.33% (CI 95%, 0.28-0.39%) in all patients on TES-MEP IONM. A relatively low prevalence of severe complications was found: cardiac-arrhythmia, bradycardia and seizure, the prevalence of this complications represents only one case in all the sample. Alongside, we report the occurrence of cardiac arrest attributable to TES-MEP IONM. CONCLUSIONS: This systematic review shows that TES-MEP is a safe procedure with a very low prevalence of complications. To our best knowledge, asystole is reported for the first time as a complication during TES-MEP IONM.

Intraoperative neurophysiological monitoring in Latin America: A bibliometric analysis.

PURPOSE: Intraoperative Neurophysiological Monitoring (IOMM) has been used worldwide in the attempt to reduce postsurgical neurological deficits, however, most of the publications are from developed countries. There is a global bibliometric analysis of IOMN in spinal surgery, however, the contribution of Latin America (LA) is not mentioned. The aim of this study is to describe scientific productivity, patterns of publications, and thematic trends of IONM in LA. METHODS: Data was collected using Scopus database, by searching scientific articles with LA affiliation, using 18 keywords. We excluded duplicates, not original articles, reviews, surveys, and articles not related to humans. Articles were analyzed and classified as follows: year of publication, language of the original document, journals metrics, country, IONM modality, etiology, location of surgery, medical specialties, and outcome. Descriptive statistics were used. RESULTS: We obtained 8,699 scientific articles of which 41 scientific articles from 7 LA countries were selected. Mexico has the highest number of publications. In most countries, supratentorial location showed the highest frequency. Somatosensory evoked potentials and electrocorticography were the most performed modalities. Neurosurgery was the most involved specialty of our 41 scientific articles, and 95.1% of these publications concluded that IONM is useful to guide surgical procedures. CONCLUSIONS: Mexico and Brazil have led IONM publications in LA. The lower reference in publications of visual evoked potentials and brainstem auditory evoked potentials IONM modalities, could be considered in the future to boost tailored research in LA.

Microsurgical Resection of Intracanalicular Vestibular Schwannoma via Retrosigmoid Approach: 3-Dimensional Operative Video.

Vestibular schwannomas are a multifaceted group of tumors that can present with different sizes and involvement of critical neurovascular structures.1-6 While operating on these tumors, a critical goal is postoperative preservation of facial nerve function and hearing. We present the case of a 66-year-old male with a history of severe left-sided tinnitus and progressive hearing loss (Video 1). Preoperative imaging depicted a lesion highly suggestive of an intracanalicular vestibular schwannoma. Due to worsening of symptoms and after thoughtful discussion with the patient, microsurgical resection was indicated under constant neurophysiologic monitoring. A retrosigmoid approach was employed, and the posterior wall of the internal auditory canal was opened, allowing exposure of tumor and its total resection. Postoperative imaging demonstrated complete tumor resection. The patient's symptoms improve, and there were no new neurologic deficits on follow-up. Anatomical images were a Courtesy of the Rhoton Collection, American Association of Neurological Surgeons (AANS)/Neurosurgical Research and Education Foundation (NREF).

Monitorización neurofisiológica intraoperatoria en cirugía de columna / Neurophisiologic monitoring in spinal surgery

The most feared complication in spinal surgeries is damage to the spinal cord due to inadvertent compression or interference in the blood supply with the consequent motor and/or sensory déficit. Intraoperative physiological surveillance reduces the risk of generating direct damage or due to hypoxia, helping in the early detection of complications. Publications in the Pubmed database are reviewed.

La complicación más temida en las cirugías de columna es el daño de la médula espinal por una compresión inadvertida o interferencia en el aporte sanguíneo con el consiguiente déficit motor y/o sensitivo. La vigilancia fisiológica intra operatoria disminuye el riesgo de generar daño directo o por hipoxia, ayudando en la detección temprana de las complicaciones. Se revisan publicaciones en base de datos Pubmed.

Manejo quirúrgico de ependimomas en médula cervical: A propósito de un caso clínico / Surgical management of ependymomas in the cervical spine: Apropos of a clinical case

Introducción: los ependimomas son tumores cerebrales que surgen de células ependimarias, células de soporte en el cerebro y la médula espinal. Representan entre el 2 y el 3% de todos los tumores cerebrales primarios. Son el cuarto tumor cerebral más común en los niños, donde el 90% de los mismos se localizan en la fosa posterior. En adultos, el 60% de estos tumores se encuentran en la médula espinal pudiendo presentarse a cualquier nivel de ésta; el caso a continuación reporta un ependimoma cervical. Objetivo: reportar un caso de ependimoma medular de ubicación poco frecuente, con resección total, sin recidiva porterior a 2 años de seguimiento.Descripción del caso: se reporta el caso de un paciente adulto, 44 años, masculino, con un síndrome medular cervical completo, progresivo, provocado por un ependimoma cervical. Intervención: se realizó laminectomía de dos espacios [C7 a T1], apertura dural, mielotomía posterior logrando exéresis total de la lesión con durorrafia a sello de agua y posterior cierre por planos sin complicaciones, con seguimiento de 2 años de sobrevida. Conclusiones: la resección total macroscópica de este tipo de tumores es muy importante para poder evitar residiva. El ependimoma cervical puede recidivar, sobre todo cuando existen residuales de la lesión. El manejo oportuno depende de gran manera de que los pacientes acudan tempranamente a valoración especializada; la resección guiada con monitorización neurofisiológica transoperatoria provee mayor oportunidad a los pacientes a no presentar secuelas permanentes y permite asimismo, mejores resultados de la rehabilitación neurológica postoperatoria

Introduction: ependymomas are brain tumors that arise from ependymal cells, supporting cells in the brain and spinal cord. They represent between 2 and 3% of all primary brain tumors. They are the fourth most common brain tumor in children, where 90% of them are located in the posterior fossa. In adults, 60% of these tumors are found in the spinal cord and can occur at any level of the spinal cord; the case below reports a cervical ependymoma. Objective: to report a case of medullary ependymoma of rare location, with total resection, without recurrence after 2 years of follow-up. Case description: a 44-year-old male adult patient with a progressive, complete cervical spinal cord syndrome, caused by a cervical ependymoma, is reported.Intervention: two-space laminectomy [C7 to T1], dural opening and posterior myelotomy were performed, achieving total excision of the lesion with water-seal durorrhaphy and subsequent closure by planes without complications, with a 2-year survival follow-up. Conclusions: macroscopic total resection of this type of tumor is very important to avoid residual. Cervical ependymoma can recur, especially when there is residual lesion. Timely management depends to a great extent on the patients attending early for a specialized evaluation; guided resection with intraoperative neurophysiological monitoring provides a greater opportunity for patients to not present permanent sequelae and also allows better results of postoperative neurological rehabilitation.

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.

Methodology for creating and validating object naming and semantic tests used by Verst-Maldaun Language Assessment during awake craniotomies.

Verst-Maldaun Language Assessment (VMLA) is a new intraoperative neuropsychological test (NT) within our local culture, e.g., native Portuguese speaking Brazilians. It aims to fill the specific need of an objective and dynamic approach for assessing the language network during awake craniotomies. The test includes object naming (ON) and semantic functions. This paper describes the process of validation, allowing for other centers to create their own language assessment. The validation process included 248 volunteers and the results were associated with age, gender and educational level (EL). The factor with the greatest impact was EL, followed by age. Intraoperative image learning by repetition is unlikely, since it is composed of 388 items and 70 combinations. The test will be available for free use under http://www.vemotests.com/ (beginning in February 2021).

Neurophysiological Intraoperative Monitoring in the Elderly.

INTRODUCTION: Intraoperative neurophysiological monitoring (IONM) is widely used to prevent nervous system injury during surgeries in elderly patients. However, there are no studies that describe the characteristics and changes in neurophysiological tests during the IONM of patients aged 60 years and older. The study aims to describe and compare IONM changes during surgeries in adult patients aged 18 to 59 years with those aged 60 years and older. METHODS: We performed a comparative retrospective study of patients aged 18 to 59 years versus those 60 aged years and older who underwent IONM during 2013 to 2018 in Mexico City. Sociodemographic characteristics were recorded and compared. Intraoperative neurophysiological monitoring techniques, their changes, and surgical procedures for both groups were analyzed and compared using descriptive statistics, Mann-Whitney U, Fisher, and χ2 tests. The sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: In total, 195 patients were analyzed: 104 patients, 68.63 ± 6.54 years old (elderly group) and 91 patients, 42.3 ± 10.5 years old (younger group). No differences were found in the rates of signal change during IONM between the group of elderly patients and the younger group. The sensitivity, specificity, and positive and negative predictive values were 80%, 99%, 80%, and 99%, respectively. CONCLUSIONS: Elderly patients have a similar rate of changes in IONM signals compared with younger patients during heterogeneous surgeries guided by IONM.

Association Between Lower Preoperative Cognition With Intraoperative Electroencephalographic Features Consistent With Deep States of Anesthesia in Older Patients: An Observational Cohort Study.

BACKGROUND: Patients with low cognitive performance are thought to have a higher risk of postoperative neurocognitive disorders. Here we analyzed the relationship between preoperative cognition and anesthesia-induced brain dynamics. We hypothesized that patients with low cognitive performance would be more sensitive to anesthetics and would show differences in electroencephalogram (EEG) activity consistent with a brain anesthesia overdose. METHODS: This is a retrospective analysis from a previously reported observational study. We evaluated cognitive performance using the Montreal cognitive assessment (MoCA) test. All patients received general anesthesia maintained with sevoflurane or desflurane during elective major abdominal surgery. We analyzed the EEG using spectral, coherence, and phase-amplitude modulation analyses. RESULTS: Patients were separated into a low MoCA group (<26 points, n = 12) and a high MoCA group (n = 23). There were no differences in baseline EEG, nor end-tidal age-corrected minimum alveolar concentration (MACage). However, under anesthesia, the low MoCA group had lower α-ß power (high MoCA: 2.9 [interquartile range {IQR}: 0.6-5.8 dB] versus low MoCA: -1.2 [IQR: -2.1 to 0.6 dB], difference 4.1 [1.0-5.7]) and a lower α peak frequency (high MoCA: 9.0 [IQR: 8.3-9.8 Hz] versus low MoCA: 7.5 [IQR: 6.3-9.0 Hz], difference 1.5 [0-2.3]) compared to the high MoCA group. The low MoCA group also had a lower α band coherence and a stronger peak-max phase-amplitude coupling (PAC). Finally, patients in the low MoCA group had longer emergence times (high MoCA 663 ± 345 seconds versus low MoCA: 960 ± 352 seconds, difference 297 [15-578]). Multiple linear regression shows up that both age and MoCA scores are independently associated with intraoperative α-ß power. CONCLUSIONS: All these EEG features, together with a prolonged emergence time, are consistent with the possibility that older patients with low cognitive performance are receiving a brain anesthesia overdose compare to cognitive normal patients.

Analysis of Intraoperative Seizures During Bipolar Brain Mapping in Eloquent Areas: Intraoperative Seizures in brain mapping.

OBJECTIVES: Awake Craniotomy (AC) is a very well described technique that is performed to make an adequate tumor resection preserving the functionality of the patient. Intraoperative Seizures (IS) are reported as a failure of such procedure. We analyze the incidence and risk factor during AC. METHODS: We made a review of the database of the National Institute of Neurology and Neurosurgery between January 2017 and May 2019 for intrinsic tumors located in eloquent areas of the brain. An analysis of ISconcerning the clinical history, clinical presentation, imaging techniques, histological findings and surgical technique was made. The factors associated with Mapping Failure (MF) were also evaluated. RESULTS: 45 patients were included of whom 7 patients (15.6%) developed IS after cortical-subcortical stimulation, 5 presented partial motor seizures (11.1%) and 2 experimented generalized secondary seizures (4.5%). Of the patients that had a MF, one patient (14%) was due to generalized tonic-clonic seizures which couldn't be managed by cold saline irrigation and administration of anti-seizures drugs and was then converted to a general anesthetic technique. We observed that the patients that had a bigger tumoral volume (112.2 cm3 85.3, P = 0,07) had a bigger positive relation in presenting IS, having a peak sensibility and specificity above 70 cc (ROC). CONCLUSIONS: In our analysis IS are more common in patients with high presurgical tumor volume. Even though the majority of the patients that presented IS didn't develop MF, it is important to acknowledge that the multidisciplinary group in the operating room must be prepared to detect these complications, treat them promptly and avoid MF.

Monitoreo neurofisiológico en cirugía de tiroides / Neurophysiological monitoring in thyroid surgery

CONTEXTO CLÍNICO: La tiroidectomía consiste en la remoción parcial o total de la glándula tiroides. Es usada tanto para tratamiento de desórdenes benignos (como bocio multinodular), así como para patología maligna. Es el procedimiento realizado con mayor frecuencia en la cirugía endocrinológica y de cabeza y cuello. Los nervios laríngeos son los responsables del movimiento de las cuerdas vocales y pueden resultar dañados durante la cirugía tiroidea. El nervio laríngeo recurrente (NLR) es la estructura más vulnerable durante el procedimiento dada su proximidad al campo quirúrgico. Su daño resulta una de las mayores complicaciones posterior a la cirugía tiroidea y paratiroidea, resultando en su parálisis que puede ser temporaria o permanente, asociándose con parálisis/paresia de las cuerdas vocales, provocando dificultad en el habla y/o problemas respiratorios. Esto lleva a un deterioro de la calidad de vida y puede conducir a una discapacidad permanente. La tasa de complicaciones asociada a lesiones neurales en cirugía tiroidea oscila entre 3 y 10% según las diferentes series y es más frecuente en cirugías más complejas como la reoperación, pacientes con cáncer con requerimiento de linfadenectomía o variaciones anatómicas entre otras. TECNOLOGÍA: El objetivo principal del monitoreo neurofisiológico intraoperatorio es la identificación durante la cirugía del deterioro de la comunicación neural, lo que permitiría al cirujano una pronta intervención con el supuesto de que la misma pueda evitar un déficit permanente. Los factores corregibles en la cirugía incluyen trastornos circulatorios, compresión excesiva por retracción, estructuras óseas, hematomas o estiramientos mecánicos, entre otros. OBJETIVO: El objetivo del presente informe es evaluar la evidencia disponible acerca de la eficacia, seguridad y aspectos relacionados a las políticas de cobertura del uso de monitoreo neurofisiológico intraoperatorio para cirugías de tiroides. MÉTODOS: Se realizó una búsqueda en las principales bases de datos bibliográficas, en buscadores genéricos de internet, y financiadores de salud. Se priorizó la inclusión de revisiones sistemáticas (RS), ensayos clínicos controlados aleatorizados (ECAs), evaluaciones de tecnologías sanitarias (ETS), evaluaciones económicas, guías de práctica clínica (GPC) y políticas de cobertura de diferentes sistemas de salud. RESULTADOS: Se incluyeron dos RS, dos GPC, y ocho informes de políticas de cobertura de monitoreo neurofisiológico intraoperatorio en cirugía de tiroides. CONCLUSIONES: Evidencia de muy baja calidad no permite concluir acerca de los posibles beneficios de monitoreo neurofisiológico en cirugía de tiroides para el primer abordaje quirúrgico de tiroides. Evidencia de baja calidad sugiere que el uso de monitoreo neurofisiológico en pacientes que requieren reoperación de tiroides disminuiría las lesiones permanentes del nervio laríngeo durante la cirugía al compararlo con la visualización directa tradicional. Asimismo, no sugiere diferencias en la ocurrencia de parálisis transitoria del nervio laríngeo post procedimiento. Hay consenso entre la mayoría de las guías de práctica clínica relevadas en recomendar el uso de esta tecnología en pacientes seleccionados (reoperaciones, glándula grande, cáncer de tiroides, entre otros), si bien no recomiendan su uso rutinario. Dentro de los financiadores de salud relevados estatales y privados, solo dos financiadores estatales (Brasil y EEUU) brindan cobertura para el procedimiento, mientras otros no lo contemplan dentro de sus políticas de cobertura o no lo mencionan. No se encontraron estudios de costo efectividad en Argentina.

The Role of Neurophysiological Monitoring during Complex Aneurysm Surgery: Report of Two Cases and Review of the Literature

The surgical treatment of intracranial aneurysms is a routine operation in the neurosurgeon practice. Complex aneurysms are those with morphological irregularities, usually large or giant; thrombosed, partially thrombosed or calcified; with aberrant fundus/neck ratio and near eloquent neurological structures. These cases demand special skills by the surgical team. The present article is a report of two cases of complex aneurysms successfully treated, with a discussion on the role of neurophysiological monitoring. In these two cases of supra- and infratentorial complex giant aneurysms, intraoperative monitoring was extremely relevant. Thus, we believe that treating complex and giant aneurysms carries several pitfalls, and the use of multimodal intraoperative monitoring is mandatory to mitigate risks and deliver the best result to the patient.