Os autores agradecem a todas as equipes clínicas que contribuem diariamente para o cuidado de pacientes neurovasculares na UCSD.

1. Configuração do simulador
<ol><li>Antes de todos os procedimentos, monte o simulador como mostrado na Figura 1 e ligue. Consulte a Tabela 1 para obter a lista completa dos equipamentos simuladores necessários para concluir cada simulação.</li>
	<li>Selecione o cenário do paciente usando a interface de software no laptop conectado(Figura 1C).</li>
	<li>Selecione a baia arterial apropriada ou o cateter guia do menu suspenso. Isso não precisa ser inserido fisicamente como parte da simulação, mas atuará como local de acesso femoral e permitirá a entrada subsequente de fios e cateteres no sistema(Figura 1D). Os tamanhos específicos de baia/guia para cada cenário são discutidos abaixo.</li>
	<li>Selecione o cateter(s) apropriado, o fio-guia e/ou o microsistema com base no cenário específico discutido abaixo(Figura 1D).</li>
	<li>Ligue fluoroscopia de plano A (PA) e B (lateral) na interface do software. Ative a fluoroscopia com os pedais do pé(Figura 1H) e ajuste tanto as posições do paciente quanto do intensificador de imagem com os joysticks(Figura 1I)até que a PA correta e as vistas laterais sejam obtidas.</li>
</ol>2. Primeiro cenário do paciente: Angiografia de quatro vasos
NOTA: Este cenário retrata um homem de 52 anos com um aneurisma carinus carótida esquerda não rompido encontrado incidentalmente em uma tomografia computadorizada não contrastante (TC) da cabeça.
<ol><li>Selecione uma baia femoral 5-francesa, um 0,035 em fio-guia e um cateter de diagnóstico 4-francês do menu suspenso como ferramentas a serem usadas nesta simulação.</li>
	<li>Insira o fio-guia na máquina simulador(Figura 1D) até que se registre na tela de simulação, sinalizando que o acesso foi obtido. Avance o fio-guia até que ele seja visualizado na aorta torácica descendente e continue no arco aórtico.</li>
	<li>Quando o fio-guia estiver seguro no arco aórtico, segure o fio-guia no lugar e insira um cateter de diagnóstico sobre o fio-guia através da baia femoral simulada para o arco aórtico.</li>
	<li>Remova o fio-guia e utilize a técnica do puff fluoroscópico pressionando suavemente a seringa de contraste (Figura 1E) para simular a injeção de contraste e opacificar brevemente os vasos à medida que o cateter é avançado para a artéria desejada.</li>
	<li>Em seguida, crie um guia de roteiro injetando contraste com a seringa de contraste(Figura 1E)enquanto o pedal fluoroscópico do pé está deprimido(Figura 1H). Em seguida, reinserir o fio para cateterizar seletivamente o vaso desejado, avançando o cateterismo sobre o fio. Remova o fio para as corridas de angiografia subsequentes. As artérias carótidas internas e externas direita e esquerda e as artérias vertebrais direita e esquerda são todas cateterizadas usando essa técnica.</li>
	<li>Utilizando o cateter de diagnóstico e a seringa de contraste simulador(Figura 1E),realize angiogramas de cada uma das circulações acima, deprimindo o pedal de fluoroscopia(Figura 1H) enquanto injeta contraste com a seringa. Obtenha visões de alta ampliação do aneurisma, se necessário. Revise os angiogramas para adequação antes de remover o cateter.</li>
	<li>Uma vez obtidas as imagens necessárias, remova o cateter/guia de diagnóstico da baia de simulação. O fechamento simulado do sítio arteriotomia femoral não é realizado.</li>
</ol>3. Segundo cenário do paciente: Coito do aneurisma do terminus carótida
NOTA: Este cenário retrata um homem de 52 anos com um conhecido aneurisma de carótida esquerda rompido, dor de cabeça grave, exame não-esftal, e uma pontuação da Escala de Coma de Glasgow de 15.
<ol><li>Selecione um cateter guia 6-francês, 0,035 em fio-guia e um cateter de diagnóstico 4-francês, a partir do menu suspenso.</li>
	<li>Insira um cateter de diagnóstico sobre um fio-guia no arco aórtico como nas etapas 2.2-2.3.</li>
	<li>Insira um cateter guia sobre o cateter de diagnóstico através do local de acesso femoral(Figura 1D) ao arco aórtico.</li>
	<li>Remova o fio-guia e crie um guia de roteiro da artéria carótida comum esquerda por farinhascopia de roteiro, injetando contraste com a seringa de contraste(Figura 1E),enquanto o pedal fluoroscópico do pé(Figura 1H)está deprimido.</li>
	<li>Reinserir o fio-guia e cateterizar seletivamente a artéria carótida comum esquerda e a artéria carótida interna usando fluoroscopia e a sobreposição do roteiro visualizada no monitor de projeção de imagem(Figura 1B)levando com o fio-guia e avançando o cateter diagnóstico e o cateter guia uma vez que o acesso seguro é adquirido.</li>
	<li>Quando o cateter guia estiver dentro da artéria carótida interna, remova o cateter e o fio diagnóstico e realize as execuções angiográficas da circulação cerebral carótida interna esquerda, deprimindo o pedal fluoroscopia(Figura 1H) enquanto injeta contraste com a seringa (Figura 1E).</li>
	<li>Meça o aneurisma utilizando a opção de cálculo na interface do software (Figura 1C). Tendo em mente que o diâmetro da bobina para a primeira bobina deve ser 1 mm mais largo do que o diâmetro médio do aneurisma, selecione uma bobina apropriada.</li>
	<li>Selecione um microcateter e microfisso do menu suspenso.</li>
	<li>Insira o microcateter e o microfismo através do local de acesso femoral(Figura 1D),e sob orientação do roteiro obtida como na etapa 3.6, cateterize seletivamente o aneurisma com o microsistema.</li>
	<li>Remova o microfio, insira a bobina previamente selecionada através do local de acesso femoral(Figura 1D),e avance-a lentamente para o aneurisma.</li>
	<li>Uma vez que a bobina esteja totalmente inserida, realize um angiograma cerebral diagnóstico deprimindo o pedal fluoroscopia (Figura 1H) enquanto injeta contraste com a seringa e avalie a patência da artéria dos pais e o preenchimento do aneurisma. O objetivo é manter a patency da artéria dos pais e embolizar completamente o aneurisma ou fornecer cobertura suficiente da cúpula ou ponto de ruptura presumido para reduzir adequadamente o risco de ruptura.</li>
	<li>Retire a bobina na interface do software(Figura 1C) e remova o fio da bobina. Se necessário, repita as etapas 3.11 e 3.12 com bobinas adicionais até que ~30% de oclusão do aneurisma seja obtida.</li>
	<li>Remova o microcateter e guie o cateter do local da baia da simulação(Figura 1D). O fechamento simulado do sítio arteriotomia femoral não é realizado.</li>
</ol>4. Terceiro cenário do paciente: Tromboctomia da artéria cerebral média esquerda
NOTA: Este cenário retrata uma mulher de 64 anos com uma pontuação do National Institutes of Health Stroke Scale (NIHSS) de 12 para afasia e fraqueza do lado direito que foi conhecida pela última vez como normal 4h antes. O CT da cabeça revelou um sinal de artéria cerebral média esquerda hiperdense (MCA) e uma pontuação de Tomografia Computadorizada (ASPECTS) do Programa de AVC de Alberta (ASPECTS) de 10, mas sem hemorragia. Um angiograma de tomografia demonstrou uma oclusão completa do segmento M1 esquerdo.
<ol><li>Selecione um cateter guia 6-francês, 0,035 em fio-guia e um cateter de diagnóstico 4-francês, a partir do menu suspenso.</li>
	<li>Insira o cateter-guia na artéria carótida interna esquerda e realize execuções angiográficas da circulação cerebral carótida interna esquerda, conforme descrito nas etapas 3.2-3.6.</li>
	<li>Selecione um microcateter/microfio e um dispositivo recuperador de stent no menu suspenso.</li>
	<li>Insira o microcateter e o microfisco no local de acesso femoral simulado(Figura 1D) e na artéria carótida interna esquerda.</li>
	<li>Sob orientação de roteiro obtida como na etapa 3.5, avance o microfisco e o microcateter para o MCA esquerdo e passe cuidadosamente pela área de oclusão. As complicações potenciais durante esta manobra incluem perfurações vasculares e/ou embolização de um coágulo rio abaixo.</li>
	<li>Remova o microfio e insira um dispositivo recuperador de stent no local de acesso femoral simulado(Figura 1D) e avance para o distal MCA para a oclusão. Em seguida, remova o microcateter, deixando o recuperador de stent no lugar ao nível da oclusão.</li>
	<li>Ligue a aspiração simulada na interface de software(Figura 1C),e retraia o dispositivo de recuperador de stent no cateter guia puxando para trás o microfisco.</li>
	<li>Remova o recuperador de stent do local de acesso femoral simulado(Figura 1D).</li>
	<li>Realize um angiograma através do cateter guia deprimindo o pedal de fluoroscopia(Figura 1H) enquanto injeta contraste com a seringa para garantir a remoção da oclusão.</li>
	<li>Remova o cateter-guia do local da baia da simulação(Figura 1D). O fechamento simulado do sítio arteriotomia femoral não é realizado.</li>
</ol>

<ol>
	<li>See, K. W., Chui, K. H., Chan, W. H., Wong, K. C., Chan, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+for+Endovascular+Simulation+Training:+A+Systematic+Review.">Evidence for Endovascular Simulation Training: A Systematic Review.</a> European Journal of Vascular and Endovascular Surgery. 51 (3), 441-451 (2016).</li><li>Pannell, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulator-Based+Angiography+and+Endovascular+Neurosurgery+Curriculum:+A+Longitudinal+Evaluation+of+Performance+Following+Simulator-Based+Angiography+Training.">Simulator-Based Angiography and Endovascular Neurosurgery Curriculum: A Longitudinal Evaluation of Performance Following Simulator-Based Angiography Training.</a> Cureus. 8 (8), 756 (2016).</li><li>Liebig, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metric-Based+Virtual+Reality+Simulation:+A+Paradigm+Shift+in+Training+for+Mechanical+Thrombectomy+in+Acute+Stroke.">Metric-Based Virtual Reality Simulation: A Paradigm Shift in Training for Mechanical Thrombectomy in Acute Stroke.</a> Stroke. 49 (7), 239-242 (2018).</li><li>Spiotta, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diagnostic+angiography+skill+acquisition+with+a+secondary+curve+catheter:+phase+2+of+a+curriculum-based+endovascular+simulation+program.">Diagnostic angiography skill acquisition with a secondary curve catheter: phase 2 of a curriculum-based endovascular simulation program.</a> Journal of Neurointerventional Surgery. 7 (10), 777-780 (2015).</li><li>Spiotta, A. M., Rasmussen, P. A., Masaryk, T. J., Benzel, E. C., Schlenk, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulated+diagnostic+cerebral+angiography+in+neurosurgical+training:+a+pilot+program.">Simulated diagnostic cerebral angiography in neurosurgical training: a pilot program.</a> Journal of Neurointerventional Surgery. 5 (4), 376-381 (2013).</li><li>Fargen, K. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experience+with+a+simulator-based+angiography+course+for+neurosurgical+residents:+beyond+a+pilot+program.">Experience with a simulator-based angiography course for neurosurgical residents: beyond a pilot program.</a> Neurosurgery. 73, 46-50 (2013).</li><li>Fargen, K. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulator+based+angiography+education+in+neurosurgery:+results+of+a+pilot+educational+program.">Simulator based angiography education in neurosurgery: results of a pilot educational program.</a> Journal of Neurointerventional Surgery. 4 (6), 438-441 (2012).</li><li>Cates, C., L&#246;nn, L., Gallagher, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prospective,+randomised+and+blinded+comparison+of+proficiency-based+progression+full-physics+virtual+reality+simulator+training+versus+invasive+vascular+experience+for+learning+carotid+artery+angiography+by+very+experienced+operators.">Prospective, randomised and blinded comparison of proficiency-based progression full-physics virtual reality simulator training versus invasive vascular experience for learning carotid artery angiography by very experienced operators.</a> BMJ Simulation and Technology Enhanced Learning. 2, 1-5 (2016).</li><li>Guo, J., Jin, X., Guo, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+the+Operational+Safety+of+a+Vascular+Interventional+Surgical+Robotic+System.">Study of the Operational Safety of a Vascular Interventional Surgical Robotic System.</a> Micromachines. 9 (3), 119 (2018).</li><li>Tedesco, M. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulation-based+endovascular+skills+assessment:+the+future+of+credentialing.">Simulation-based endovascular skills assessment: the future of credentialing.</a> Journal of Vascular Surgery. 47 (5), 1008 (2008).</li></ol>

A AAK já recebeu subsídios competitivos da Covidien Ltd. e penumbra Inc. e possui arranjos de consultoria para treinamento médico com Stryker Neurovascular, Covidien Ltd., e Penumbra Inc.JSP atuou como consultor médico da Stryker Neurovascular e Dart NeuroScience LLC. A AAK e a JSP não têm interesses financeiros diretos relacionados a este trabalho. Os demais autores não têm divulgações sobre os materiais ou métodos utilizados neste estudo ou os achados especificados neste artigo.

A cirurgia endovascular é um campo em expansão que oferece uma abordagem de tratamento minimamente invasiva para uma variedade de patologias. Os riscos significativos associados às lesões vasculares, no entanto, proporcionam desafios educacionais únicos. Com os avanços no treinamento baseado em simulação, a formação de estagiários agora permite a prática em um ambiente livre de riscos que imita casos da vida real. Assim, o treinamento baseado em simulação endovascular tem sido mostrado para melhorar consist...

O treinamento baseado em simulação é uma ferramenta educacional estabelecida para estagiários médicos e é particularmente benéfico em áreas de alto risco, como neurocirurgia endovascular. Existem vários dispositivos de treinamento em realidade virtual utilizando sistemas baseados em cateter, como o simulador ANGIO Mentor (Simbionix Ltd., Airport City, Israel) e os simuladores VIST-C e VIST G5 (Mentice AB, Gotemburgo, Suécia), com um conjunto significativo de dados demonstrando a utilidade do treinamento sobre aptidão processual1. Apesar da utilidade dos simuladores, faltam instruções processuais passo a passo para seu uso.
Apresentado é um protocolo detalhado para o uso do simulador ANGIO Mentor, um sistema que suporta melhorias de competência em procedimentos de neurocirurgia endovascular comuns, incluindo angiogramas cerebrais diagnósticos, trombectomias mecânicas e embolizações de bobinas de aneurisma2. Trabalhos prévios mostram que após estagiários de todos os níveis realizarem cinco angiogramas simulados, cinco trombectomias e dez embolizações de bobinas de aneurisma no simulador ANGIO Mentor, apresentaram melhorias significativas no tempo processual, fluoroscopia e doses de contraste, e eventos técnicos adversos2.
As seguintes instruções passo a passo são divididas em cenários de caso e podem ser facilmente integradas a um currículo de formação acadêmica para estudantes de medicina, residentes ou bolsistas2. Deve-se notar, no entanto, que é necessário uma compreensão básica dos tratamentos de anatomia arterial, angiografia e derrame e aneurisma para otimizar o potencial educacional do dispositivo de simulação.
Todos os procedimentos descritos abaixo (ou seja, angiograma cerebral diagnóstico, enrolamento de aneurisma carótida terminus, trombectomia mecânica) podem ser realizados por um único operador usando o simulador ANGIO Mentor (Simbionix Ltd.) (Figura 1). Este dispositivo de treinamento permite que estagiários neurocirúrgicos de todos os níveis de habilidade obtenham exposição a técnicas endovasculares em um ambiente pré-clínico, com os três cenários de pacientes utilizados com base em um currículo publicado anteriormente para treinamento de angiografia baseado em simulador2. Para reproduzir técnicas endovasculares com alta fidelidade, o simulador utiliza cateteres e fios reais introduzidos através de uma porta semelhante ao diafragma de uma baia da artéria femoral. Os fios e cateteres envolvem rolos internos que registram movimentos rotacionais e translacionais, que são exibidos nos monitores. Seleções de dispositivos e sinais vitais do paciente também são visíveis para o operador do simulador.

<table>
	<tbody>
		<tr>
			<td>ANGIO Mentor simulator</td>
			<td>Simbionix Ltd., Airport City, Israel</td>
			<td>N/a</td>
			<td>The setup for the ANGIO Mentor simulator includes the simulator housing as pictured in Figure 1: (A), an external monitor for image projection (x-ray, angiography; B), a laptop for interfacing with the Simbionix Software (C), the simulated femoral artery sheath (with an outer guide-catheter, inner diagnostic microcatheter and guidewire shown; D), a contrast syringe (E), an insufflator for balloon inflation (F), a stent delivery device (G; not used in these patient scenarios), foot pedals for fluoroscopy, roadmap guidance, and angiographic runs (H), and the operator control panel on the simulator housing where the operator is able to control patient and image intensifier positioning (I).</td>
		</tr>
	</tbody>
</table>

simulator training for endovascular neurosurgery

O treinamento baseado em simulações tornou-se prática comum em especialidades médicas, especialmente para aprender habilidades complexas realizadas em ambientes de alto risco. No campo da neurocirurgia endovascular, a demanda por ambientes de aprendizagem sem consequências e sem riscos levou ao desenvolvimento de dispositivos de simulação valiosos para estagiários médicos. O objetivo deste protocolo é fornecer diretrizes instrutivas para o uso de um simulador de neurocirurgia endovascular em um ambiente acadêmico. O simulador oferece aos trainees a oportunidade de receber feedback realista sobre seus conhecimentos sobre anatomia, bem como feedback háptico indicativo de seu sucesso no manuseio dos sistemas baseados em cateter sem consequências negativas. Também é discutida a utilidade desse protocolo específico em relação a outras modalidades de treinamento neuroendovascular.

O simulador ANGIO Mentor foi previamente mostrado para melhorar as habilidades dos estagiários cirúrgicos com experiência neuroendovascular variada ao realizar angiogramas diagnósticos simulados, trombectomias e embolizações de bobinas de aneurisma rompidas em um ambiente acadêmico2. Neste estudo, foram estabelecidas métricas de desempenho para os procedimentos supracitados ao longo de 30 dias em um estudante de medicina, um residente em neurocirurgia, dois bolsistas de neuroradiologia dia...

Watch this Scientific Journal Video about Simulator Training for Endovascular Neurosurgery at JoVE.com

Simulator Training for Endovascular Neurosurgery

A simulação de procedimentos complexos e de alto risco é fundamental para a formação de estagiários médicos. Um protocolo para treinamento de neurocirurgia endovascular baseada em simulador em um ambiente acadêmico controlado é descrito. O protocolo inclui diretrizes stepwise para estagiários de diferentes níveis, com discussão sobre as vantagens e limitações desse modelo.

Treinamento de simulador para neurocirurgia endovascular

Simulation-based training has become common practice across medical specialties, especially for learning complex skills performed in high-risk ...

simulator-training-for-endovascular-neurosurgery

Research

JoVE Journal

Neuroscience

3.5K visualizações.  University of California. A simulação de procedimentos complexos e de alto risco é fundamental para a formação de estagiários médicos. Um protocolo para treinamento de neurocirurgia endovascular baseada em simulador em um ambiente acadêmico controlado é descrito. O protocolo inclui diretrizes stepwise para estagiários de diferentes níveis, com discussão sobre as vantagens e limitações desse modelo.

Vídeo: Simulator Training for Endovascular Neurosurgery

Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat

Stroke is the leading cause of disability and the third leading cause of death in adults worldwide1. In human stroke, there exists a highly variable clinical state; in the development of animal models of focal ischemia, however, achieving reproducibility of experimentally induced infarct volume is essential. The rat is a widely used animal model for stroke due to its relatively low animal husbandry costs and to the similarity of its cranial circulation to that of humans2,3. In humans, the middle cerebral artery (MCA) is most commonly affected in stroke syndromes and multiple methods of MCA occlusion (MCAO) have been described to mimic this clinical syndrome in animal models. Because recanalization commonly occurs following an acute stroke in the human, reperfusion after a period of occlusion has been included in many of these models. In this video, we demonstrate the transient endovascular suture MCAO model in the spontaneously hypertensive rat (SHR). A filament with a silicon tip coating is placed intraluminally at the MCA origin for 60 minutes, followed by reperfusion. Note that the optimal occlusion period may vary in other rat strains, such as Wistar or Sprague-Dawley. Several behavioral indicators of stroke in the rat are shown. Focal ischemia is confirmed using T2-weighted magnetic resonance images and by staining brain sections with 2,3,5-triphenyltetrazolium chloride (TTC) 24 hours after MCAO.

Surgical induction of ischemic brain damage in the rat is a widely used model for stroke research. Here we demonstrate the induction of focal cerebral ischemia by occlusion of the middle cerebral artery. Visualization of the resulting infarct by histological staining and magnetic resonance imaging is also shown.

Modelo de isquemia focal cerebral por oclusão Suture Endovascular da artéria cerebral média no Rat

Stroke is the leading cause of disability and the third leading cause of death in adults worldwide1. In human stroke, there exists a highly variable ...

Neurociência

MPI CyberMotion Simulator: Implementation of a Novel Motion Simulator to Investigate Multisensory Path Integration in Three Dimensions

Path integration is a process in which self-motion is integrated over time to obtain an estimate of one's current position relative to a starting point 1. Humans can do path integration based exclusively on visual 2-3, auditory 4, or inertial cues 5. However, with multiple cues present, inertial cues - particularly kinaesthetic - seem to dominate 6-7. In the absence of vision, humans tend to overestimate short distances (&lt;5 m) and turning angles (&lt;30&deg;), but underestimate longer ones 5. Movement through physical space therefore does not seem to be accurately represented by the brain.
Extensive work has been done on evaluating path integration in the horizontal plane, but little is known about vertical movement (see 3 for virtual movement from vision alone). One reason for this is that traditional motion simulators have a small range of motion restricted mainly to the horizontal plane. Here we take advantage of a motion simulator 8-9 with a large range of motion to assess whether path integration is similar between horizontal and vertical planes. The relative contributions of inertial and visual cues for path navigation were also assessed.
16 observers sat upright in a seat mounted to the flange of a modified KUKA anthropomorphic robot arm. Sensory information was manipulated by providing visual (optic flow, limited lifetime star field), vestibular-kinaesthetic (passive self motion with eyes closed), or visual and vestibular-kinaesthetic motion cues. Movement trajectories in the horizontal, sagittal and frontal planes consisted of two segment lengths (1st: 0.4 m, 2nd: 1 m; &plusmn;0.24 m/s2 peak acceleration). The angle of the two segments was either 45&deg; or 90&deg;. Observers pointed back to their origin by moving an arrow that was superimposed on an avatar presented on the screen.
Observers were more likely to underestimate angle size for movement in the horizontal plane compared to the vertical planes. In the frontal plane observers were more likely to overestimate angle size while there was no such bias in the sagittal plane. Finally, observers responded slower when answering based on vestibular-kinaesthetic information alone. Human path integration based on vestibular-kinaesthetic information alone thus takes longer than when visual information is present. That pointing is consistent with underestimating and overestimating the angle one has moved through in the horizontal and vertical planes respectively, suggests that the neural representation of self-motion through space is non-symmetrical which may relate to the fact that humans experience movement mostly within the horizontal plane.

An efficient way to gain insight into how humans navigate themselves in three dimensions is described. The method takes advantage of a motion simulator capable of moving observers in ways unattainable by traditional simulators. Results confirm that movement in the horizontal plane is underestimated, while vertical movement is overestimated.

MPI Simulator CyberMotion: Implementação de um simulador de movimento Novela Caminho para Investigar Integração multisensorial em Três Dimensões

Path integration is a process in which self-motion is integrated over time to obtain an estimate of one's current position relative to a starting point 1. ...

Extinction Training During the Reconsolidation Window Prevents Recovery of Fear

Fear is maladaptive when it persists long after circumstances have become safe. It is therefore crucial to develop an approach that persistently prevents the return of fear. Pavlovian fear-conditioning paradigms are commonly employed to create a controlled, novel fear association in the laboratory. After pairing an innocuous stimulus (conditioned stimulus, CS) with an aversive outcome (unconditioned stimulus, US) we can elicit a fear response (conditioned response, or CR) by presenting just the stimulus alone1,2 . Once fear is acquired, it can be diminished using extinction training, whereby the conditioned stimulus is repeatedly presented without the aversive outcome until fear is no longer expressed3. This inhibitory learning creates a new, safe representation for the CS, which competes for expression with the original fear memory4. Although extinction is effective at inhibiting fear, it is not permanent. Fear can spontaneously recover with the passage of time. Exposure to stress or returning to the context of initial learning can also cause fear to resurface3,4.
Our protocol addresses the transient nature of extinction by targeting the reconsolidation window to modify emotional memory in a more permanent manner. Ample evidence suggests that reactivating a consolidated memory returns it to a labile state, during which the memory is again susceptible to interference5-9. This window of opportunity appears to open shortly after reactivation and close approximately 6hrs later5,11,16, although this may vary depending on the strength and age of the memory15. By allowing new information to incorporate into the original memory trace, this memory may be updated as it reconsolidates10,11. Studies involving non-human animals have successfully blocked the expression of fear memory by introducing pharmacological manipulations within the reconsolidation window, however, most agents used are either toxic to humans or show equivocal effects when used in human studies12-14. Our protocol addresses these challenges by offering an effective, yet non-invasive, behavioral manipulation that is safe for humans.
By prompting fear memory retrieval prior to extinction, we essentially trigger the reconsolidation process, allowing new safety information (i.e., extinction) to be incorporated while the fear memory is still susceptible to interference. A recent study employing this behavioral manipulation in rats has successfully blocked fear memory using these temporal parameters11. Additional studies in humans have demonstrated that introducing new information after the retrieval of previously consolidated motor16, episodic17, or declarative18 memories leads to interference with the original memory trace14. We outline below a novel protocol used to block fear recovery in humans.

Conditioned fear can be diminished through an inhibitory process called extinction, but can resurface under conditions such as the passage of time or exposure to stress. Our protocol presents a novel way of preventing fear recovery by introducing extinction during the reconsolidation window (the re-storage phase of a reactivated memory).

Formação extinção durante a janela de reconsolidação impede a recuperação do Medo

Fear is maladaptive when it persists long after circumstances have become safe. It is therefore crucial to develop an approach that persistently prevents ...

Exposure of the Pig CNS for Histological Analysis: A Manual for Decapitation, Skull Opening, and Brain Removal

Pigs have become increasingly popular in large-animal translational neuroscience research as an economically and ethically feasible substitute to non-human primates. The large brain size of the pig allows the use of conventional clinical brain imagers and the direct use and testing of neurosurgical procedures and equipment from the human clinic. Further macroscopic and histological analysis, however, requires postmortem exposure of the pig central nervous system (CNS) and subsequent brain removal. This is not an easy task, as the pig CNS is encapsulated by a thick, bony skull and spinal column. The goal of this paper and instructional video is to describe how to expose and remove the postmortem pig brain and the pituitary gland in an intact state, suitable for subsequent macroscopic and histological analysis.

The goal of this paper and instructional video is to describe how to expose and remove the postmortem pig brain and pituitary gland in an intact state, suitable for subsequent macroscopic and histological analysis.

Exposição do SNC porco para análise histológica: A manual por decapitação, crânio de abertura, e Cérebro Remoção

Pigs have become increasingly popular in large-animal translational neuroscience research as an economically and ethically feasible substitute to ...

Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations

Arteriovenious malformations (AVMs) are associated with significant morbidity and mortality, and have a rupture risk of ~3% per year. Treatment of AVMs must be tailored specifically to the lesion, with surgical resection being the gold standard for small, accessible lesions. Pre-operative embolization of AVMs can reduce nidal blood flow and remove high-risk AVM features such as intranidal or venous aneurysms, thereby simplifying a challenging neurosurgical procedure. Herein, we describe our approach for the staged endovascular embolization and open resection of AVMs, and highlight the advantages of having a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. This includes planning the craniotomy and resection to immediately follow the final embolization stage, thereby using a single session of anesthesia for aggressive embolization, and rapid resection. Finally, we provide a representative case of a 22-year-old female with an unruptured right frontal AVM diagnosed during a seizure workup, who was successfully treated via staged embolizations followed by open surgical resection.

Surgery is the gold standard for accessible arteriovenious malformations (AVMs), and pre-operative embolization can simplify this procedure. We describe our approach for staged endovascular embolization and open resection of AVMs, and provide a representative clinical example highlighting the advantages of a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team.

Tratamento cirúrgico aberto de malformações arteriovenosas cerebrais e abrangente Endovascular

Arteriovenious malformations (AVMs) are associated with significant morbidity and mortality, and have a rupture risk of ~3% per year. Treatment of AVMs ...

A Protocol for the Administration of Real-Time fMRI Neurofeedback Training

Neurologic disorders are characterized by abnormal cellular-, molecular-, and circuit-level functions in the brain. New methods to induce and control neuroplastic processes and correct abnormal function, or even shift functions from damaged tissue to physiologically healthy brain regions, hold the potential to dramatically improve overall health. Of the current neuroplastic interventions in development, neurofeedback training (NFT) from functional Magnetic Resonance Imaging (fMRI) has the advantages of being completely non-invasive, non-pharmacologic, and spatially localized to target brain regions, as well as having no known side effects. Furthermore, NFT techniques, initially developed using fMRI, can often be translated to exercises that can be performed outside of the scanner without the aid of medical professionals or sophisticated medical equipment. In fMRI NFT, the fMRI signal is measured from specific regions of the brain, processed, and presented to the participant in real-time. Through training, self-directed mental processing techniques, that regulate this signal and its underlying neurophysiologic correlates, are developed. FMRI NFT has been used to train volitional control over a wide range of brain regions with implications for several different cognitive, behavioral, and motor systems. Additionally, fMRI NFT has shown promise in a broad range of applications such as the treatment of neurologic disorders and the augmentation of baseline human performance. In this article, we present an fMRI NFT protocol developed at our institution for modulation of both healthy and abnormal brain function, as well as examples of using the method to target both cognitive and auditory regions of the brain.

The ability to induce and/or control neural plasticity may be critical in future treatments for neurologic disorders and the recovery from brain injury. In this paper, we present a protocol on the use of neurofeedback training with functional magnetic resonance imaging to modulate human brain function.

Um protocolo para a administração do real-time fMRI treinamento de Neurofeedback

Neurologic disorders are characterized by abnormal cellular-, molecular-, and circuit-level functions in the brain. New methods to induce and control ...

Fiber Connections of the Supplementary Motor Area Revisited: Methodology of Fiber Dissection, DTI, and Three Dimensional Documentation

The purpose of this study is to show the methodology for the examination of the white matter connections of the supplementary motor area (SMA) complex (pre-SMA and SMA proper) using a combination of fiber dissection techniques on cadaveric specimens and magnetic resonance (MR) tractography. The protocol will also describe the procedure for a white matter dissection of a human brain, diffusion tensor tractography imaging, and three-dimensional documentation. The fiber dissections on human brains and the 3D documentation were performed at the University of Minnesota, Microsurgery and Neuroanatomy Laboratory, Department of Neurosurgery. Five postmortem human brain specimens and two whole heads were prepared in accordance with Klingler's method. Brain hemispheres were dissected step by step from lateral to medial and medial to lateral under an operating microscope, and 3D images were captured at every stage. All dissection results were supported by diffusion tensor imaging. Investigations on the connections in line with Meynert's fiber tract classification, including association fibers (short, superior longitudinal fasciculus I and frontal aslant tracts), projection fibers (corticospinal, claustrocortical, cingulum, and frontostriatal tracts), and commissural fibers (callosal fibers) were also conducted.

The purpose of this study is to show each step of the fiber dissection technique on human cadaveric brains, the 3D documentation of these dissections, and the diffusion tensor imaging of the anatomically dissected fiber pathways.

Conexões de Fibra da Área Suplementar de Motor Revisitada: Metodologia de Dissecção de Fibras, DTI e Documentação Tridimensional

The purpose of this study is to show the methodology for the examination of the white matter connections of the supplementary motor area (SMA) complex ...

Optimized Management of Endovascular Treatment for Acute Ischemic Stroke

This manuscript describes a streamlined protocol for the management of patients with acute ischemic stroke, which aims at the minimization of time from hospital admission to reperfusion. Rapid restoration of cerebral blood flow is essential for the outcomes of patients with acute ischemic stroke. Endovascular treatment (EVT) has become the standard of care to accomplish this in patients with acute stroke due to large vessel occlusion (LVO). To achieve reperfusion of ischemic brain regions as fast as possible, all in-hospital time delays have to be carefully avoided. Therefore, management of patients with acute ischemic stroke was optimized with an interdisciplinary standard operating procedure (SOP). Stroke neurologists, diagnostic as well as interventional neuroradiologists, and anesthesiologists streamlined all necessary processes from patient admission and diagnosis to EVT of eligible patients. Target times for every step were established. Actually achieved times were prospectively recorded along with clinical data and imaging scores for all endovascularly treated stroke patients. These data were regularly analyzed and discussed in interdisciplinary team meetings. Potential issues were evaluated and all staff involved was trained to adhere to the SOP. This streamlined patient management approach and enhanced interdisciplinary collaboration reduced time from patient admission to reperfusion significantly and was accompanied by a beneficial effect on clinical outcomes.

The outcome of patients with acute ischemic stroke depends on swift restoration of cerebral blood flow. This protocol aims at optimizing the management of such patients by minimizing peri-procedural timings and rendering the time from hospital admission to reperfusion as short as possible.

Gerenciamento otimizado de tratamento Endovascular para acidente vascular cerebral isquêmico agudo

This manuscript describes a streamlined protocol for the management of patients with acute ischemic stroke, which aims at the minimization of time from ...

Real-Time fMRI Brain Mapping in Animals

Dynamic fMRI responses vary largely according to the physiological conditions of animals either under anesthesia or in awake states. We developed a real-time fMRI platform to guide experimenters to monitor fMRI responses instantaneously during acquisition, which can be used to modify the physiology of animals to achieve desired hemodynamic responses in animal brains. The real-time fMRI set-up is based on a 14.1T preclinical MRI system, enabling the real-time mapping of dynamic fMRI responses in the primary forepaw somatosensory cortex (FP-S1) of anesthetized rats. Instead of a retrospective analysis to investigate confounding sources leading to the variability of fMRI signals, the real-time fMRI platform provides a more effective scheme to identify dynamic fMRI responses using customized macro-functions and a common neuroimage analysis software in the MRI system. Also, it provides immediate troubleshooting feasibility and a real-time biofeedback stimulation paradigm for brain functional studies in animals.

Animal brain functional mapping can benefit from the real-time functional magnetic resonance imaging (fMRI) experimental set-up. Using the latest software implemented in the animal MRI system, we established a real-time monitoring platform for small animal fMRI.

Mapeamento cerebral por fMRI em tempo real em animais

Dynamic fMRI responses vary largely according to the physiological conditions of animals either under anesthesia or in awake states. We developed a ...

Endovascular Perforation Model for Subarachnoid Hemorrhage Combined with Magnetic Resonance Imaging (MRI)

The endovascular filament perforation model to mimic subarachnoid hemorrhage (SAH) is a commonly used model - however, the technique can cause a high mortality rate as well as an uncontrollable volume of SAH and other intracranial complications such as stroke or intracranial hemorrhage. In this protocol, a standardized SAH mouse model is presented, induced by endovascular filament perforation, combined with magnetic resonance imaging (MRI) 24 h after operation to ensure the correct bleeding site and exclude other relevant intracranial pathologies. Briefly, C57BL/6J mice are anesthetized with an intraperitoneal ketamine/xylazine (70 mg/16 mg/kg body weight) injection and placed in a supine position. After midline neck incision, the common carotid artery (CCA) and carotid bifurcation are exposed, and a 5-0 non-absorbable monofilament polypropylene suture is inserted in a retrograde fashion into the external carotid artery (ECA) and advanced into the common carotid artery. Then, the filament is invaginated into the internal carotid artery (ICA) and pushed forward to perforate the anterior cerebral artery (ACA). After recovery from surgery, mice undergo a 7.0 T MRI 24 h later. The volume of bleeding can be quantified and graded via postoperative MRI, enabling a robust experimental SAH group with the option to perform further subgroup analyses based on blood quantity.

Endovascular Perforation Model for Subarachnoid Hemorrhage Combined with Magnetic Resonance Imaging MRI

Here we present a standardized SAH mouse model, induced by endovascular filament perforation, combined with magnetic resonance imaging (MRI) 24 h after operation to ensure the correct bleeding site and exclude other relevant intracranial pathologies.

Modelo de perfuração endovascular para hemorragia subaracnóide combinada com ressonância magnética (RM)

The endovascular filament perforation model to mimic subarachnoid hemorrhage (SAH) is a commonly used model - however, the technique can cause a high ...