Updates in the Diagnosis and Treatment of Paraneoplastic Neurologic Syndromes.

The disorders of the central nervous system associated with cancer by remote immune-mediated mechanisms are a heterogeneous group. These disorders encompass the classic paraneoplastic disorders and the recently recognized autoimmune encephalitis associated with antibodies against neuronal cell surface or synaptic proteins that occur with or without cancer association. In the last decade, the new surge of interest in neuronal diseases associated with anti-neuronal antibodies led to the rapid discovery of new forms of disease that have different manifestations and were not previously suspected to be immune mediated. The recognition of these syndromes is important because it may lead to early detection of an underlying malignancy and prompt initiation of treatment, improving chances for a better outcome.

Intracranial germinoma causing cerebral haemiatrophy and hypopituitarism.

A young woman presented with primary amenorrhoea, progressive haemiparesis, visual disturbance, dementia and focal motor seizures. Investigations showed hypopituitarism, unilateral cerebral atrophy and inflamed cerebrospinal fluid. A trans-sphenoidal biopsy gave a unifying diagnosis of a pituitary germinoma.

Young-Onset Alzheimer Dementia Due to a Novel Pathogenic Presenilin 1 Variant Initially Misdiagnosed as Autoimmune Encephalitis.

OBJECTIVES: Pathogenic variants in presenilin 1 (PSEN1) are related to early-onset Alzheimer disease (AD) and may occur as de novo variants. In comparison with sporadic forms, it can present with psychiatric manifestations, seizures, myoclonus, and focal presentation. Because PSEN1 can occur in young patients who lack a family history of neurologic disorders and because these symptoms are also frequent in autoimmune encephalitis (AE), diagnosis may be overlooked. Our aim was to demonstrate the challenge in diagnosing young patients with neurodegenerative diseases that simulate AE. METHODS: We describe a case of a young patient with insidious progressive dementia, myoclonus, seizures, and aphasia, with no family history of dementia, along with signs suggestive of neuroinflammation on brain MRI and CSF examination. RESULTS: She was initially misdiagnosed as having AE. Further investigation was performed, leading to the discovery of a novel and de novo pathogenic variant in PSEN1. DISCUSSION: This case demonstrates the importance of considering PSEN1 in young patients with insidious progressive dementia with atypical clinical and neuroimaging features, even in patients without a family history of neurologic disorders. Not adhering to published criteria of possible and probable AE and overinterpretation of subtle inflammatory findings in CSF and MRI contribute to misdiagnosis.

Antibodies Against ZSCAN1 in Pediatric and Adult Patients With Non-Paraneoplastic ROHHAD Syndrome.

OBJECTIVES: To report the association of zinc finger and SCAN domain containing 1 antibodies (ZSCAN1-abs) with rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome in patients without tumor. METHODS: Patients with symptoms compatible with ROHHAD syndrome but without an associated tumor were selected from our database. Serum and CSF samples were examined for the presence of ZSCAN1-abs by an in-house cell-based assay. In addition, samples from 149 patients with several inflammatory and noninflammatory disorders and 50 healthy participants served as controls. RESULTS: Thirteen patients with ROHHAD syndrome were identified. Of these, we had paired serum/CSF samples from 6 patients and only serum from the other 7. Five of 6 patients (83.3%) with paired serum/CSF (4 children, 1 adult) had ZSCAN-abs only in CSF and 1 had antibodies in serum and CSF. ZSCAN1-abs were not detected in the remaining 7 patients with ROHHAD with only serum available or in any of the 199 control samples. DISCUSSION: Patients with ROHHAD syndrome should be investigated for the presence of ZSCAN1-abs in CSF. The antibodies do not necessarily predict the presence of a tumor. The detection of ZSCAN1-abs in an adult patient suggests that this condition also occurs beyond the pediatric age.

A critical review and update on autoimmune encephalitis: understanding the alphabet soup.

Autoimmune encephalitis (AE) comprises a group of diseases mediated by antibodies against neuronal cell surface or synaptic antigens, such as ion channels or neurotransmitter receptors. New clinical syndromes and their associated antibodies were and are still being characterized over the last two decades. The fact that their main clinical features are interdisciplinary, - encompassing neuropsychiatric symptoms, cognitive dysfunction, epileptic seizures, movement and sleep disorders - has led to a surge of interest in this field. Some of these diseases present with a well-defined syndrome, being recognizable on clinical grounds. Correct diagnosis is important since AE are potentially treatable diseases, despite their severity. On the other hand, an increasing number of neuronal antibodies being described casts doubt upon the way we should utilize antibody testing and interpret results. In this article we review, summarize and update the current knowledge on antibody mediated encephalitis.

Potential autoimmune encephalitis following yellow fever vaccination: A report of three cases.

Meningoencephalitis following yellow fever vaccination is considered a viral neuroinvasive disease. We describe three patients with typical autoimmune encephalitis syndromes that developed 1-27 days following yellow fever vaccination. Anti-N-methyl-d-aspartate-r antibodies were identified in the CSF and serum of two patients and the other case was associated with anti-neurexin-3 antibodies. One case was confirmed as vaccine-associated neurotropic disease due to reactive CSF yellow fever IgM, which suggested an infectious-autoimmune overlap mechanism. Two aditional cases of Anti-N-methyl-d-aspartate-r encephalitis were identified in the literature review. Antibody-positive autoimmune encephalitis should be included in the differential diagnosis of neurologic adverse events following yellow fever vaccination.

Frequency and Characterization of Movement Disorders in Anti-IgLON5 Disease.

OBJECTIVE: Anti-IgLON5 disease is a recently described neurological disease that shares features of autoimmunity and neurodegeneration. Abnormal movements appear to be frequent and important but have not been characterized and are under-reported. Here we describe the frequency and types of movement disorders in a series of consecutive patients with this disease. METHODS: In this retrospective, observational study, the presence and phenomenology of movement disorders were assessed with a standardized clinical questionnaire. Available videos were centrally reviewed by three experts in movement disorders. RESULTS: Seventy two patients were included. In 41 (57%) the main reason for initial consultation was difficulty walking along with one or several concurrent movement disorders. At the time of anti-IgLON5 diagnosis, 63 (87%) patients had at least one movement disorder with a median of three per patient. The most frequent abnormal movements were gait and balance disturbances (52 patients, 72%), chorea (24, 33%), bradykinesia (20, 28%), dystonia (19, 26%), abnormal body postures or rigidity (18, 25%), and tremor (15, 21%). Other hyperkinetic movements (myoclonus, akathisia, myorhythmia, myokymia, or abdominal dyskinesias) occurred in 26 (36%) patients. The craniofacial region was one of the most frequently affected by multiple concurrent movement disorders (23 patients, 32%) including dystonia (13), myorhythmia (6), chorea (4) or myokymia (4). Considering any body region, the most frequent combination of multiple movement disorders consisted of gait instability or ataxia associated with craniofacial dyskinesias or generalized chorea observed in 31(43%) of patients. In addition to abnormal movements, 87% of patients had sleep alterations, 74% bulbar dysfunction, and 53% cognitive impairment. Fifty-five (76%) patients were treated with immunotherapy, resulting in important and sustained improvement of the movement disorders in only seven (13%) cases. CONCLUSIONS: Movement disorders are a frequent and leading cause of initial neurological consultation in patients with anti-IgLON5 disease. Although multiple types of abnormal movements can occur, the most prevalent are disorders of gait, generalized chorea, and dystonia and other dyskinesias that frequently affect craniofacial muscles. Overall, anti-IgLON5 disease should be considered in patients with multiple movement disorders, particularly if they occur in association with sleep alterations, bulbar dysfunction, or cognitive impairment.

Clinical Features and Inflammatory Markers in Autoimmune Encephalitis Associated With Antibodies Against Neuronal Surface in Brazilian Patients.

Acute encephalitis is a debilitating neurological disorder associated with brain inflammation and rapidly progressive encephalopathy. Autoimmune encephalitis (AE) is increasingly recognized as one of the most frequent causes of encephalitis, however signs of inflammation are not always present at the onset which may delay the diagnosis. We retrospectively assessed patients with AE associated with antibodies against neuronal surface diagnosed in reference centers in Northeast of Brazil between 2014 to 2017. CNS inflammatory markers were defined as altered CSF (pleocytosis >5 cells/mm3) and/or any brain parenchymal MRI signal abnormality. Thirteen patients were evaluated, anti-NMDAR was the most common antibody found (10/13, 77%), followed by anti-LGI1 (2/13, 15%), and anti-AMPAR (1/13, 7%). Median time to diagnosis was 4 months (range 2-9 months). Among these 13 patients, 6 (46.1%) had inflammatory markers and when compared to those who did not present signs of inflammation, there were no significant differences regarding the age of onset, time to diagnosis and modified Rankin scale score at the last visit. Most of the patients presented partial or complete response to immunotherapy during follow-up. Our findings suggest that the presence of inflammatory markers may not correlate with clinical presentation or prognosis in patients with AE associated with antibodies against neuronal surface. Neurologists should be aware to recognize clinical features of AE and promptly request antibody testing even without evidence of inflammation in CSF or MRI studies.

A critical review and update on autoimmune encephalitis: understanding the alphabet soup / Revisão crítica e atualizações em encefalites autoimunes: entendendo a sopa de letrinhas

ABSTRACT Autoimmune encephalitis (AE) comprises a group of diseases mediated by antibodies against neuronal cell surface or synaptic antigens, such as ion channels or neurotransmitter receptors. New clinical syndromes and their associated antibodies were and are still being characterized over the last two decades. The fact that their main clinical features are interdisciplinary, - encompassing neuropsychiatric symptoms, cognitive dysfunction, epileptic seizures, movement and sleep disorders - has led to a surge of interest in this field. Some of these diseases present with a well-defined syndrome, being recognizable on clinical grounds. Correct diagnosis is important since AE are potentially treatable diseases, despite their severity. On the other hand, an increasing number of neuronal antibodies being described casts doubt upon the way we should utilize antibody testing and interpret results. In this article we review, summarize and update the current knowledge on antibody mediated encephalitis.

RESUMO As encefalites autoimunes compreendem um grupo de doenças mediadas por anticorpos contra antígenos de superfície neuronal ou sinapse, como canais iônicos ou receptores de neurotransmissores. Novas síndromes clínicas e os anticorpos a elas associados foram e ainda estão sendo caracterizados ao longo das últimas duas décadas. Dado que suas principais características clínicas são interdisciplinares, isto é, incluem -se sintomas neuropisquiátricos, disfunção cognitiva, crises epilépticas, distúrbio do movimento e do sono, há uma grande onda de interesse sobre esse campo de conhecimento. Algumas dessas doenças apresentam-se com uma síndrome bem definida, sendo possível reconhecê-las clinicamente. Diagnosticá-las corretamente é importante uma vez que se trata de doenças potencialmente tratáveis apesar da gravidade que lhes é característica. Por outro lado, o número crescente de anticorpos sendo descritos causam dúvida frequente sobre qual o melhor teste a solicitar e como interpretá-los. Nós aqui apresentamos uma revisão atualização resumida do conhecimento atual sobre as encefalites mediadas por anticorpos.

Investigations in GABAA receptor antibody-associated encephalitis.

OBJECTIVE: To report the clinical features, comorbidities, receptor subunit targets, and outcome in patients with anti-GABAA receptor (GABAAR) encephalitis. METHODS: Clinical study of 26 patients, including 17 new (April 2013-January 2016) and 9 previously reported patients. Antibodies to α1, ß3, and γ2 subunits of the GABAAR were determined using reported techniques. RESULTS: Patients' median age was 40.5 years (interquartile range 48.5 [13.75-62.35] years; the youngest 2.5 months old; 13 female). Symptoms included seizures (88%), alteration of cognition (67%), behavior (46%), consciousness (42%), or abnormal movements (35%). Comorbidities were identified in 11 (42%) patients, including 7 tumors (mostly thymomas), 2 herpesvirus encephalitis (herpes simplex virus 1, human herpesvirus 6; coexisting with NMDAR antibodies), and 2 myasthenia without thymoma. Brain MRI was abnormal in 23 (88%) patients, showing in 20 (77%) multifocal, asynchronous, cortical-subcortical T2/fluid-attenuated inversion recovery abnormalities predominantly involving temporal (95%) and frontal (65%) lobes, but also basal ganglia and other regions. Immunologic or tumor therapy resulted in substantial improvement in 18/21 (86%) assessable patients; the other 3 (14%) died (2 status epilepticus, 1 sepsis). Compared with adults, children were more likely to have generalized seizures (p = 0.007) and movement disorders (p = 0.01) and less likely to have a tumor (p = 0.01). The main epitope targets were in the α1/ß3 subunits of the GABAAR. CONCLUSIONS: Anti-GABAAR encephalitis is characterized by frequent seizures and distinctive multifocal cortical-subcortical MRI abnormalities that provide an important clue to the diagnosis. The frequency of symptoms and comorbidities differ between children (more viral-related) and adults (more tumor-related). The disorder is severe but most patients respond to treatment.

The importance of recognizing faciobrachial dystonic seizures in rapidly progressive dementias.

BACKGROUND: Creutzfeldt-Jakob Disease (CJD) is the prototypical cause of rapidly progressive dementia (RPD). Nonetheless, efforts to exclude reversible causes of RPD that mimic prion disease are imperative. The recent expanding characterization of neurological syndromes associated with antibodies directed against neuronal cell surface or sympathic antigens, namely autoimmune encephalitis is shifting paradigms in neurology. Such antigens are well known proteins and receptors involved in synaptic transmission. Their dysfunction results in neuropsychiatric symptoms, psychosis, seizures, movement disorders and RPD. Faciobrachial dystonic seizure (FBDS) is a novel characterized type of seizure, specific for anti-LGI1 encephalitis. OBJECTIVE: In order to improve clinical recognition we report the cases of two Brazilian patients who presented with characteristic FDBS (illustrated by videos) and anti-LGI1 encephalitis. METHODS: We have included 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 Clínicas, 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 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.

EMBASAMENTO: A doença de Creutzfeldt-Jakob (DCJ) é o protótipo de demência rapidamente progressiva (DRP). No entanto, é imperativo que sejam excluídas causas reversíveis de DRPs que possam simular doença priônica. A recente caracterização de síndromes neurológicas associadas a anticorpos direcionados contra antígenos de superfície neuronal ou sinapse, assim denominadas de encefalites autoimunes, está mudando paradigmas em neurologia. Esses antígenos estão envolvidos na transmissão sináptica, sendo que as disfunções destes podem resultar em sintomas neuropsiquiátricos, psicose, crises epilépticas, distúrbios do movimento e DRP. A crise distônica faciobraquial (CDFB) é um tipo de crise recentemente caracterizada e específica da encefalite anti-LGI1. OBJETIVO: Para promover um melhor reconhecimento da doença relatamos os casos de 2 pacientes brasileiros que apresentaram CDFBs (ilustradas com vídeos) associadas à encefalite anti-LGI1. MÉTODOS: Foram incluídos todos os pacientes com CDFBs e encefalite anti-LGI1 confirmados em 2 centros brasileiros terciários: Departamento de Neurologia do Hospital das Clínicas da Universidade de São Paulo, São Paulo, Brasil e o Hospital Geral de Fortaleza entre 01 de janeiro de 2011 e 31 de dezembro de 2015. RESULTADOS: Ambos os casos apresentaram quadro clinico típico de encefalite límbica associada a CDFBs e exame do LCR sem alterações. Nenhum caso associou-se à presença de neoplasia e ambos apresentaram boa resposta à imunoterapia. CONCLUSÃO: A CDFB podem ser confundidas com mioclonias e ocorrer simultaneamente com rápido declínio cognitivo, o seu não reconhecimento pode induzir ao diagnóstico errôneo de uma causa potencialmente tratável de DRP como sendo DCJ.

A patient with a long history of relapsing psychosis and mania presenting with anti-NMDA receptor encephalitis ten years after first episode.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a recently discovered autoimmune disorder, in which antibodies target NMDARs in the brain, leading to their removal from synapses. Early in the disease course, patients often present with marked psychosis and mood disturbances (i.e. mania, depression), explaining why most of these patients are first seen by psychiatrists. Hence, autoimmune encephalitis is receiving growing attention from psychiatry, mainly owing to concerns over misdiagnosing immunomediated and potentially curable disorders as primary psychiatric disorders, such as schizophrenia or major depressive disorder. Although anti-NMDAR encephalitis occurs in the context of new-onset psychiatric symptoms, there is a lack of information on differential diagnosis and treatment of this disorder after a long-term diagnostic history of functional psychiatric disorders. We report a case of a patient with a long history of bipolar affective disorder evolving with anti-NMDAR encephalitis, initially misdiagnosed as non-organic psychosis.

A encefalite antirreceptor N-metil-D-aspartato (NMDA) é uma doença autoimmune recentemente descoberta, na qual anticorpos têm como alvo os receptors NMDA no cérebro, levando à sua remoção da sinapse. Os pacientes frequentemente desenvolvem psicose e distúrbios de humor proeminentes nas fases iniciais da doença (i.e: mania e depressão), o que explica o fato de que a maioria destes pacientes seja vista primeiramente por psiquiatras. Consequentemente, as encefalites autoimunes têm recebido atenção crescente pela psiquiatria, principalmente pela preocupação de erroneamente diagnosticar doenças imunomediadas e potencialmente tratáveis como doenças psiquiátricas primárias, como esquizofrenia ou transtorno depressivo maior. Embora a encefalite antirreceptor NMDA ocorra no contexto de sintomas psiquiátricos de início recente, há carência de informações sobre o diagnóstico diferencial e tratamento desta doença após o diagnóstico de doenças psiquiátricas funcionais de longa data. Aqui, nós apresentamos o caso de uma paciente com diagnóstico de transtorno afetivo bipolar de longa data evoluindo com encefalite antirreceptor NMDA, inicialmente diagnosticada erroneamente como uma psicose não-orgânica.

A successful case of anti-NMDAR encephalitis without tumor treated with a prolonged regimen of plasmapheresis.

Anti-NMDA receptor encephalitis is a severe but treatable autoimmune disease of the CNS. However, the use of immunotherapy and long-term outcomes have yet to be defined for this disease. We describe a case of an 18-year-old male diagnosed with anti-NMDAR encephalitis not associated with tumor, which did not respond to initial treatment with immunoglobulin, followed by corticosteroids, cyclophosphamide and evolved with significant clinical improvement after a prolonged course of plasmapheresis. Although it is not possible to affirm the good outcome was due solely to the prolonged plasmapheresis regimen, recently published data shows that improvement may take weeks or months to occur. This case discloses another therapeutic possibility for patients with refractory disease who fail to respond to recommended first-line and second-line therapy.

A encefalite antirreceptor de NMDA é uma grave doença autoimune do sistema nervoso central, mas responsiva a tratamento. No entanto o uso da imunoterapia e o prognóstico a longo prazo ainda não foram estabelecidos para esta doença. Aqui nós descrevemos o caso de um homem de 18 anos de idade diagnosticado com encefalite antirreceptor de NMDA, não associada a tumor, o qual provavelmente não respondeu à terapia inicial com corticosteroides, ciclofosfamida e, o qual evoluiu com melhora clínica importante após um curso prolongado de plasmaférese. Embora não seja possível atribuir o desfecho favorável apenas ao regime de plasmaférese prolongado, uma vez que publicações recentes demonstram que a resposta à imunoterapia pode levar semanas à meses, nosso caso abre uma possibilidade terapêutica nova para casos com doença refratária, não responsivos ao tratamento de primeira e segunda-linha preconizados.

Native Valve Endocarditis due to Enterococcus hirae Presenting as a Neurological Deficit.

Enterococcus hirae is a rare isolate in clinical specimens. We describe a case of native aortic valve endocarditis in a 56-year-old man. This is the third reported case of endocarditis due to this organism, the first without recurrence of endocarditis and the first presenting as a neurological deficit.

The importance of recognizing faciobrachial dystonic seizures in rapidly progressive dementias / A importância do reconhecimento das crises distônicas faciobraquiais nas demências rapidamente progressivas

ABSTRACT Background: Creutzfeldt-Jakob Disease (CJD) is the prototypical cause of rapidly progressive dementia (RPD). Nonetheless, efforts to exclude reversible causes of RPD that mimic prion disease are imperative. The recent expanding characterization of neurological syndromes associated with antibodies directed against neuronal cell surface or sympathic antigens, namely autoimmune encephalitis is shifting paradigms in neurology. Such antigens are well known proteins and receptors involved in synaptic transmission. Their dysfunction results in neuropsychiatric symptoms, psychosis, seizures, movement disorders and RPD. Faciobrachial dystonic seizure (FBDS) is a novel characterized type of seizure, specific for anti-LGI1 encephalitis. Objective: In order to improve clinical recognition we report the cases of two Brazilian patients who presented with characteristic FDBS (illustrated by videos) and anti-LGI1 encephalitis. Methods: We have included 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 Clínicas, 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 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.

RESUMO Embasamento: A doença de Creutzfeldt-Jakob (DCJ) é o protótipo de demência rapidamente progressiva (DRP). No entanto, é imperativo que sejam excluídas causas reversíveis de DRPs que possam simular doença priônica. A recente caracterização de síndromes neurológicas associadas a anticorpos direcionados contra antígenos de superfície neuronal ou sinapse, assim denominadas de encefalites autoimunes, está mudando paradigmas em neurologia. Esses antígenos estão envolvidos na transmissão sináptica, sendo que as disfunções destes podem resultar em sintomas neuropsiquiátricos, psicose, crises epilépticas, distúrbios do movimento e DRP. A crise distônica faciobraquial (CDFB) é um tipo de crise recentemente caracterizada e específica da encefalite anti-LGI1. Objetivo: Para promover um melhor reconhecimento da doença relatamos os casos de 2 pacientes brasileiros que apresentaram CDFBs (ilustradas com vídeos) associadas à encefalite anti-LGI1. Métodos: Foram incluídos todos os pacientes com CDFBs e encefalite anti-LGI1 confirmados em 2 centros brasileiros terciários: Departamento de Neurologia do Hospital das Clínicas da Universidade de São Paulo, São Paulo, Brasil e o Hospital Geral de Fortaleza entre 01 de janeiro de 2011 e 31 de dezembro de 2015. Resultados: Ambos os casos apresentaram quadro clinico típico de encefalite límbica associada a CDFBs e exame do LCR sem alterações. Nenhum caso associou-se à presença de neoplasia e ambos apresentaram boa resposta à imunoterapia. Conclusão: A CDFB podem ser confundidas com mioclonias e ocorrer simultaneamente com rápido declínio cognitivo, o seu não reconhecimento pode induzir ao diagnóstico errôneo de uma causa potencialmente tratável de DRP como sendo DCJ.

A patient with a long history of relapsing psychosis and mania presenting with anti-NMDA receptor encephalitis ten years after first episode / Paciente com longo curso de psicose e mania recorrentes apresentando encefalite antirreceptor NMDA dez anos após o primeiro episódio

Anti-N-methyl- D-aspartate receptor (NMDAR) encephalitis is a recently discovered autoimmune disorder, in which antibodies target NMDARs in the brain, leading to their removal from synapses. Early in the disease course, patients often present with marked psychosis and mood disturbances (i.e. mania, depression), explaining why most of these patients are first seen by psychiatrists. Hence, autoimmune encephalitis is receiving growing attention from psychiatry, mainly owing to concerns over misdiagnosing immunomediated and potentially curable disorders as primary psychiatric disorders, such as schizophrenia or major depressive disorder. Although anti-NMDAR encephalitis occurs in the context of new-onset psychiatric symptoms, there is a lack of information on differential diagnosis and treatment of this disorder after a long-term diagnostic history of functional psychiatric disorders. We report a case of a patient with a long history of bipolar affective disorder evolving with anti-NMDAR encephalitis, initially misdiagnosed as non-organic psychosis.

A encefalite antirreceptor N-metil-D-aspartato (NMDA) é uma doença autoimmune recentemente descoberta, na qual anticorpos têm como alvo os receptors NMDA no cérebro, levando à sua remoção da sinapse. Os pacientes frequentemente desenvolvem psicose e distúrbios de humor proeminentes nas fases iniciais da doença (i.e: mania e depressão), o que explica o fato de que a maioria destes pacientes seja vista primeiramente por psiquiatras. Consequentemente, as encefalites autoimunes têm recebido atenção crescente pela psiquiatria, principalmente pela preocupação de erroneamente diagnosticar doenças imunomediadas e potencialmente tratáveis como doenças psiquiátricas primárias, como esquizofrenia ou transtorno depressivo maior. Embora a encefalite antirreceptor NMDA ocorra no contexto de sintomas psiquiátricos de início recente, há carência de informações sobre o diagnóstico diferencial e tratamento desta doença após o diagnóstico de doenças psiquiátricas funcionais de longa data. Aqui, nós apresentamos o caso de uma paciente com diagnóstico de transtorno afetivo bipolar de longa data evoluindo com encefalite antirreceptor NMDA, inicialmente diagnosticada erroneamente como uma psicose não-orgânica.