[PubMed] [Google Scholar] 25. all patients with FBDS and confirmed anti-LGI1 encephalitis and video records of FDBS in two tertiary Brazilian centers: Department of Neurology of Hospital das Clnicas, Sao Paulo University, Sao Paulo, Brazil and Hospital Geral de Fortaleza, Fortaleza, Brazil between January 1, 2011 and December 31, 2015. Results Both patients presented with clinical features of limbic encephalitis associated with FBDS, hyponatremia and normal JAK-IN-1 CSF. None of them presented with tumor and both showed a good response after immunotherapy. Conclusion FBDSs may be confounded with myoclonus and occurs simultaneously with rapid cognitive decline. Unawareness of FDBS may induce to misdiagnosing a treatable cause of RPD as CJD. JAK-IN-1 Keywords: anti-LGI1 encephalitis, faciobrachial dystonic seizures, autoimmune encephalitis, rapidly progressive dementias, Creutzfeldt-Jakob disease Abstract Embasamento A doen?a de Creutzfeldt-Jakob (DCJ) o prottipo de demncia rapidamente progressiva (DRP). No entanto, imperativo que sejam excludas causas reversveis de DRPs que possam simular doen?a pri?nica. A recente caracteriza??o de sndromes neurolgicas associadas a anticorpos direcionados contra antgenos de superfcie neuronal ou sinapse, assim denominadas de encefalites autoimunes, est mudando paradigmas em neurologia. Esses antgenos est?o envolvidos na transmiss?o sinptica, sendo que as disfun??es destes podem resultar em sintomas neuropsiquitricos, psicose, crises epilpticas, distrbios do movimento e DRP. A crise dist?nica faciobraquial (CDFB) um tipo de crise recentemente caracterizada e especfica da encefalite anti-LGI1. Objetivo Para promover um melhor reconhecimento da doen?a relatamos os casos de 2 pacientes brasileiros que apresentaram CDFBs (ilustradas com vdeos) associadas encefalite anti-LGI1. Mtodos Foram includos todos os pacientes com CDFBs e encefalite anti-LGI1 confirmados em 2 centros brasileiros tercirios: Departamento de Neurologia do Hospital das Clnicas da Universidade de S?o Paulo, S?o Paulo, Brasil e o Hospital Geral de Fortaleza entre 01 de janeiro FOS de 2011 e 31 JAK-IN-1 de dezembro de 2015. Resultados Ambos os casos apresentaram quadro clinico tpico de encefalite lmbica associada JAK-IN-1 a CDFBs e exame do LCR sem altera??es. Nenhum caso associou-se presen?a de neoplasia e ambos apresentaram boa resposta imunoterapia. Conclus?o A CDFB podem ser confundidas com mioclonias e ocorrer simultaneamente com rpido declnio cognitivo, o seu n?o reconhecimento pode induzir ao diagnstico err?neo de uma causa potencialmente tratvel de DRP como sendo DCJ. INTRODUCTION Unlike the more common dementing conditions that typically progress over years, rapidly progressive dementias (RPDs) can develop subacutely over weeks or months. They pose a challenge to neurologists because prompt, thorough and accurate diagnosis is mandatory given that treatable or even curable diseases can be the cause of RPDs. Data from dementia centers attributes 6.4% to 27% of RPD to potentially treatable etiologies.1-3 Autoimmune encephalitis, i.e. encephalitis associated with antibodies against neuronal surface or synaptic antigens, and Creutzfeldt-Jakob Disease (CJD), may present with similar clinical, radiologic, electrophysiologic, and laboratory findings.4-8 Antibody testing and response to immunotherapy are reliable tools to confirm diagnosis of autoimmune encephalitis, however, they are not readily accessible and results can take several weeks.9 Thus, clinical clues to appropriately help discriminate these two conditions are of paramount importance. For example: hyponatremia, seizures, cerebral spinal fluid (CSF), pleocytosis brain abnormalities on T2-weighted and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI restricted to medial temporal lobes) are not expected in prion diseases yet are typically found in autoimmune encephalitis. Faciobrachial dystonic seizures (FDBS) is definitely a distinctive adult-onset, high-frequency, very brief and highly specific antiepileptic resistant seizure and almost pathognomonic for anti-leucine-rich-glioma inactivated 1 (LGI1) encephalitis.10-12 Because FDBS manifest as sudden, myoclonic-like jerks, they can be easily mistaken for myoclonus, a clinical getting included in all diagnostic criteria of CJD.13-15 Hence, FDBS in the context of rapidly progressive dementia can lead to erroneous analysis. In our encounter, it is important for neurologists to be familiarized with this novel entity to avoid pitfalls when evaluating individuals with RPD. Statement OF Instances Case 1. A 72-year-old man presented with progressive cognitive decrease and episodes of stereotyped motions of the face and right.