Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular transmission leading to generalized or localized muscle weakness due most frequently to the presence of autoantibodies against acetylcholine receptors in the postsynaptic motor end-plate. Myasthenic crisis (MC) is a complication of MG characterized by worsening muscle weakness, resulting in respiratory failure that requires intubation and mechanical ventilation. It also includes postsurgical patients, in whom exacerbation of muscle weakness from MG causes a delay in extubation. MC is a very important, serious, and reversible neurological emergency that affects 20-30% of the myasthenic patients, usually within the first year of illness and maybe the debut form of the disease. Most patients have a predisposing factor that triggers the crisis, generally an infection of the respiratory tract. Immunoglobulins, plasma exchange, and steroids are the cornerstones of immunotherapy. Today with the modern neurocritical care, mortality rate of MC is less than 5%.Key words: myasthenic crisis, myasthenia gravis, respiratory failure, immunosupressive therapy, thymectomy. ReSUMOMiastenia grave (MG) é um distúbio autoimune que afeta principalmente a transmissão neuromuscular, levando a fraqueza muscular generalizada ou localizada. É devida mais frequentemente à presença de auto-anticorpos anti-receptores de acetilcolina na fenda pós-sináptica da placa motora. A crise miastênica (CM) é uma complicação da MG caracterizada por piora da fraqueza muscular, resultando en falência respiratória, o que requer entubação endotraqueal e ventilação mecânica.Isto ocorre também em pacientes pós-cirúrgicos, em que há piora da fraqueza muscular devido à MG, causando um atraso na extubação. MC é uma emergência neurológica importante, séria e reversível que afeta 20-30% dos pacientes miastênicos, usualmente duranteo primeiro ano de enfermidade, podendo a crise miastênica ser a manifestação inicial da MG. A maioria dos pacientes tem fatores predisponentes que desencadeiam a crise, geralmente uma infecção do trato respiratório. Imunoglobulina, plasmaférese e esteróides são a pedra angular da imunoterapia. Hoje, dentro da terapia neurocrítica, a taxa de mortalidade na CM é menor que 5%.

Electroencephalography (EEG) remains an important complementary tool to diagnose neurologic diseases, including encephalitis. The objectives of this short review are to show the electroencephalographic findings in different types of encephalitis and to highlight the changing outlines during and after the specific treatment. In our study, we did a non-systematic review of literature on the role of EEG in infectious and autoimmune encephalitis. We concluded that EEG can be very useful in the diagnosis and follow-up of different types of encephalitis. Early changes during the illness can have an impact on prognosis.

Coronavirus disease 2019 (COVID-19) disease caused by a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been associated with many neurological symptoms. The purpose of this article is to describe the neurological manifestations so far reported and their probable pathogenesis. We conducted a literature review on EMBASE, MEDLINE and SCIELO databases using the terms "COVID-19", "COVID", "neurological", "neurologic", "manifestations", "implications", "Guillain-Barre syndrome", "encephalopathy". A total of 33 articles including clinical series, retrospective studies, and case reports were selected and thoroughly reviewed to describe neurological manifestations of COVID-19. There are several neurological manifestations of SARS-CoV-2 infection with different clinical presentations, severity, and prevalence. The most critical ones, such as cerebrovascular disease, encephalopathy, and Guillain-Barre syndrome, were less common and usually associated with previous medical history, known risk factors for cerebrovascular disease or advanced age. The main hypotheses for the spread of the virus are through the hematogenous route or the cribriform plate of the ethmoid bone or a disseminated severe immune response by a cytokine storm. The presence of neurological disturbances associated with laboratory tests alterations is an important clue for the physicians to promptly recognize neurological manifestations of SARS-CoV-2.