A estimulação magnética transcraniana é um método não invasivo de estimulação do córtex humano. Conhecida pela sigla TMS, do inglês transcranial magnetic stimulation, a técnica foi introduzida por Barker et al. em 1985. Seu funcionamento baseia-se na Lei de Faraday, na qual um intenso campo magnético que varia rapidamente é capaz de induzir um campo elétrico na superfície do cérebro, despolarizando os neurônios no córtex cerebral. Devido à sua versatilidade, a TMS é utilizada atualmente tanto no âmbito da pesquisa quanto em aplicações clínicas. Entre as aplicações clínicas, a TMS é utilizada como ferramenta diagnóstica e também como técnica terapêutica de algumas doenças neurodegenerativas e distúrbios psiquiátricos como a depressão, a doença de Parkinson e o tinnitus. Quanto à ferramenta diagnóstica, destaca-se o mapeamento motor, uma técnica de delimitação da área de representação do músculo-alvo em sua superfície cortical, cuja aplicabilidade pode ser em estudos da fisiologia cerebral para avaliar danos ao córtex motor e trato corticoespinhal. Esta revisão teve como objetivo introduzir a física, os elementos básicos, os princípios biológicos e as principais aplicações da TMS.
BackgroundTraining in medical education depends on the availability of standardized materials that can reliably mimic the human anatomy and physiology. One alternative to using cadavers or animal bodies is to employ phantoms or mimicking devices. Styrene-ethylene/butylene-styrene (SEBS) gels are biologically inert and present tunable properties, including mechanical properties that resemble the soft tissue. Therefore, SEBS is an alternative to develop a patient-specific phantom, that provides real visual and morphological experience during simulation-based neurosurgical training.ResultsA 3D model was reconstructed and printed based on patient-specific magnetic resonance images. The fused deposition of polyactic acid (PLA) filament and selective laser sintering of polyamid were used for 3D printing. Silicone and SEBS materials were employed to mimic soft tissues. A neuronavigation protocol was performed on the 3D-printed models scaled to three different sizes, 100%, 50%, and 25% of the original dimensions. A neurosurgery team (17 individuals) evaluated the phantom realism as “very good” and “perfect” in 49% and 31% of the cases, respectively, and rated phantom utility as “very good” and “perfect” in 61% and 32% of the cases, respectively. Models in original size (100%) and scaled to 50% provided a quantitative and realistic visual analysis of the patient’s cortical anatomy without distortion. However, reduction to one quarter of the original size (25%) hindered visualization of surface details and identification of anatomical landmarks.ConclusionsA patient-specific phantom was developed with anatomically and spatially accurate shapes, that can be used as an alternative for surgical planning. Printed models scaled to sizes that avoided quality loss might save time and reduce medical training costs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.