ABSTRACT
Abstract Objectives To review the diagnostic criteria for encephalitis and encephalopathy of presumed infectious etiology, as well as the diagnostic workup for viral encephalitis and its treatment approaches. The authors also intended to summarize relevant information on specific viruses frequently found in Brazil. Source of data Literature search on Pubmed/MEDLINE using the following keywords: "viral", "encephalitis", "child", or "adolescents", filtering for articles on humans and in English. Summary of data Viral encephalitis is the most common cause of encephalitis and is responsible for high rates of morbidity, permanent neurologic sequelae, and according to the virus, may have high mortality rates. The most common etiologies are herpesviruses 1 and 2 (HSV-1 and HSV-2), non-polio enterovirus, and arboviruses (in Brazil, dengue, Zika, and chikungunya). Other relevant etiologies are seasonal influenza, cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and the re-emergent measles. Conclusion Clinical data, laboratory results, and neuroimaging findings support the diagnosis of encephalitis and the specific viral etiology. To increase the likelihood of etiologic confirmation, it is important to know the best approach to collecting samples and to choose the best identification technique for each virus. The differential diagnosis of viral encephalitis includes other infections and immune-mediated inflammatory central nervous system disorders.
Resumo Objetivos Revisar os critérios diagnósticos para encefalite e encefalopatia de etiologia infecciosa presumida, assim como a investigação diagnóstica para encefalite viral e suas abordagens terapêuticas. Além disso, pretendemos resumir tópicos relevantes sobre os vírus específicos frequentemente encontrados no Brasil. Fonte de dados Pesquisa bibliográfica feita nos bancos de dados Pubmed/Medline utilizando as seguintes palavras-chave: "viral", "encephalitis", "child" ou "adolescents", limitando os artigos a estudos em humanos e escritos em inglês. Resumo dos dados A encefalite viral é a causa mais comum de encefalite e é responsável por altas taxas de morbidade, sequelas neurológicas permanentes e, de acordo com o vírus, altas taxas de mortalidade. As etiologias mais comuns são herpes vírus 1 e 2 (HSV-1 e HSV-2), enterovírus não pólio e arbovírus (no Brasil, Dengue, Zika e Chikungunya). Outras etiologias relevantes são a influenza sazonal, o citomegalovírus (CMV), o vírus Epstein-Barr (EBV), o herpes vírus humano 6 (HHV-6) e o sarampo reemergente. Conclusão Dados clínicos, resultados laboratoriais e de neuroimagem apoiam o diagnóstico de encefalite e a etiologia viral específica. Para aumentar a probabilidade de confirmação etiológica, é importante conhecer a melhor abordagem para coletar amostras e escolher a melhor técnica de identificação para cada vírus. O diagnóstico diferencial de encefalite viral inclui outras infecções e distúrbios inflamatórios do sistema nervoso central imunomediados.
Subject(s)
Humans , Child , Adolescent , Encephalitis, Viral/diagnosis , Encephalitis, Viral/therapy , Brazil , Herpesvirus 6, Human , Herpesvirus 4, Human , Cytomegalovirus , Zika Virus , Zika Virus InfectionABSTRACT
While systemic viral infections are exceptionally common, symptomatic viral infections of the brain parenchyma itself are very rare, but a serious neurologic condition. It is estimated that viral encephalitis occurs at a rate of 1.4 cases per 100.000 inhabitants. Geography is a major determinant of encephalitis caused by vector-borne pathogens. A diagnosis of viral encephalitis could be a challenge to the clinician, since almost 70% of viral encephalitis cases are left without an etiologic agent identified. In this review, the most common viral encephalitis will be discussed, with focus on ecology, diagnosis, and clinical management.
Embora as infecções virais sistêmicas sejam muito comuns, as infecções virais sintomáticas do parênquima cerebral são raras, mas potencialmente graves. Estima-se que a encefalite viral ocorra em 1,4 casos por 100.000 habitantes anualmente. A localização geográfica é um fator determinante a ser levado em consideração frente aos patógenos transmitidos por vetores. O diagnóstico clínico das encefalites virais pode ser um desafio para o clínico, visto que quase 70% dos casos de encefalite viral ficam sem a identificação do agente viral. Nesta revisão, as encefalites virais mais comuns serão discutidas, com interesse especial sobre os aspectos da ecologia, do diagnóstico e do seu manejo clínico.
Subject(s)
Humans , Encephalitis, Viral/diagnosis , Encephalitis, Viral/virology , Diagnosis, Differential , Encephalitis, Viral/therapyABSTRACT
Viral encephalitis is a severe illness that produces inflammation of the brain. CNS viral infections frequently occur as a complication of systemic viral infections. Over 100 viruses are implicated as causative agents, including herpes simplex virus type I which is the most common agent implied in non-epidemic encephalitis in all population groups in the world, and is responsible for the most severe cases in all ages. Many viruses, for which there are vaccines, may also cause encephalitis: measles, mumps, polio, rabies, rubella, and chickenpox. The virus causes an inflammation of the brain tissue, which may progress to destruction of nerve cells, cause bleeding and brain damage, leading to severe encephalitis, such as hemorrhagic or necrotizing encephalitis, with a worse prognosis, producing serious sequelae or death. The clinical evolution includes the presence of headache, fever and altered consciousness rapidly progressive. The outcome of viral encephalitis is variable, some cases are mild, with full recovery, but there are serious cases that can cause severe sequel in the brain. To diagnose this illness as soon as possible is essential, through laboratory tests (biochemistry, virus PCR, culture) and neuroimaging (CT, MRI) and above all, the establishment of early treatment to prevent the development of the process and possible complications. The prognosis worsens if the initiation of treatment is delayed.
Subject(s)
Encephalitis, Viral/diagnosis , Encephalitis, Viral/therapy , Antiviral Agents/therapeutic use , Child , Diagnosis, Differential , Encephalitis, Viral/virology , Humans , Prognosis , Polymerase Chain ReactionABSTRACT
El objetivo fue revisar la encefalitis en niños y adolescentes, su etiología, manifestaciones clínicas, fisiopatología, métodos diagnósticos y tratamiento, enfatizando las manifestaciones neuropsiquiátricas de la encefalitis durante una epidemia de influenza. La encefalitis se considera una inflamación del sistema nervioso central (SNC) que compromete el cerebro. Se manifiesta usualmente por cefaleas, fiebre y trastorno del estado de conciencia. Puede además manifestarse por convulsiones, cambios en la personalidad y manifestaciones obsesivas (síntomas neuropsiquiátricos). Las manifestaciones dependerán del tipo de virus y las células afectadas. La encefalitis puede ser causada por una gran variedad de agentes infecciosos incluyendo virus, bacterias, hongos y parásitos. Causas virales de encefalitis incluyen herpesvirus, arbovirus, rabia y enterovirus. Casos establecidos de bacterias incluyen Borrelia burgdorferi y rickettsia y el Mycoplasma neumoniae, al cual se atribuyen varios casos de encefalitis. Otros agentes como el hongo Coccidioides immitis e Histoplasma capsulatum pueden también generarla. Más de 100 agentes se han asociado a encefalitis. El diagnóstico de encefalitis constituye un reto para el clínico, y su etiología infecciosa usualmente se identifica entre el 40% al 70% de casos. El diagnóstico se hace con absoluta certeza sólo con una biopsia cerebral. La epidemiología depende de ciertos factores como la edad, la localización geográfica, la época del año, las condiciones climáticas y la inmunocompetencia del huésped. El tratamiento temprano puede disminuir el riesgo de muerte y las secuelas. Describimos cuatro pacientes con encefalitis y manifestaciones neuropsiquiátricas durante una epidemia de influenza, con el fin de alertar sobre esta asociación.
The aim is to review the encephalitis in infants and adolescents as well as its etiology, clinical manifestation, epidemiology, physiopathology, diagnostic methods and treatment, and the neuropsyquiatric signs appearing an influenza epidemy. Encephalitis is an inflammation of the central nervous system (CNS) which involves the brain. The clinical manifestations usually are: headache, fever and confusional stage. It could also be manifested as seizures, personality changes, or psiqyiatric symptoms. The clinical manifestations are related to the virus and the cell type affected in the brain. A meningitis or encephalopathy need to be ruled out. It could be present as an epidemic or isolated form, beeing this the most frequent form. It could be produced by a great variety of infections agents including virus, bacterias, fungal and parasitic. Viral causes are herpesvirus, arbovirus, rabies and enterovirus. Bacterias such as Borrelia burgdorferi, Rickettsia and Mycoplasma neumoniae. Some fungal causes are: Coccidioides immitis and Histoplasma capsulatum. More than 100 agents are related to encephalitis. The diagnosis of encephalitis is a challenge for the clinician and its infectious etiology is clear in only 40 to 70% of all cases. The diagnosis of encephalitis can be established with absolute certainty only by the microscopic examination of brain tissue. Epidemiology is related to age of the patients, geographic area, season, weather or the host immune system. Early intervention can reduce the mortality rate and sequels. We describe four patients with encephalitis and neuropsychiatric symptoms during an influenza epidemic.
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Male , Brain Diseases/virology , Encephalitis, Viral/diagnosis , Influenza, Human/diagnosis , Acute Disease , Brain Diseases/diagnosis , Brain Diseases/therapy , Diagnosis, Differential , Encephalitis, Viral/physiopathology , Encephalitis, Viral/therapy , Influenza, Human/physiopathology , Influenza, Human/therapy , PrognosisABSTRACT
La encefalitis por Herpes Simple tipo 1 es una enfermedad grave. Su pronóstico depende del diagnóstico y tratamiento precoz. Se analizan cuatro historias clínicas de niños con encefalitis herpética diagnosticada por Reacción en Cadena de la Polimerasa (PCR) en líquido cefalorraquídeo (LCR) entre marzo de 1995 y marzo de 1997. Se trata de tres lactantes y un escolar. Todos presentaron manifestaciones clínicas similares al ingreso: fiebre, depresión neurosíquica (DNS) y convulsiones (parciales o generalizadas). El análisis citoquímico del LCR al ingreso fue normal en tres casos. Los hallazgos tomográficos en la evolución fueron idénticos: infarto fronto témporo parietal. En un sólo caso se valoró el fondo de ojo al inicio. Tres pacientes tuvieron evolución clínica similar: profundización de la DNS, convulsiones y signos locales. Todos quedaron con secuelas, que fueron más graves en los pacientes en los que el tratamiento se instaló tardíamente. Con el objetivo de protocolizar las indicaciones de la búsqueda viral por PCR y de mejorar el pronóstico de estos pacientes se propone un algoritmo de diagnóstico, estudio y tratamiento para esta enfermedad