Neurotoxoplasmose em pacientes imunocomprometidos e a relevância do diagnóstico por imagem / Neurotoxoplasmosis in immunocompromised patients and the relevance of image diagnosis

Introdução: a toxoplasmose é causada por um protozoário intracelular obrigatório, o Toxoplasma gondii. Felídeos, como gatos domésticos, são hospedeiros definitivos enquanto o homem é hospedeiro intermediário. Normalmente a infecção por T. gondii é assintomática e benigna, mas em indivíduos imunocomprometidos como portadores da AIDS, pode ocorrer reativação da doença crônica. Como o HIV apresenta neurotropismo, a neurotoxoplasmose é a causa predominante de distúrbios neurológicos nesses pacientes. As manifestações clínicas, principalmente os achados em exames de imagem específicos como a tomografia e a ressonância magnética do crânio, constituem a melhor forma de diagnóstico. Objetivo: neste contexto, analisou-se neste estudo a relevância do diagnóstico por imagem na neurotoxoplasmose em pacientes HIV positivos. Método: foi realizada uma revisão sistemática da literatura científica em bases de dados como: Bireme, Scielo, Medline, Google Acadêmico e Pudmed para os seguintes descritores: Diagnóstico por imagem, Neurotoxoplasmose, Sorodiagnóstico da AIDS, Ressonância Magnética e Tomografia Computadorizada. Foram incluídos na seleção artigos, teses, dissertações, atlas, livros, sites e guias em Português e em Inglês, publicados entre os anos de 1977 a 2015. Resultados e discussão: observou-se que dentre os exames de imagem mais utilizados, destacam-se a tomografia computadorizada (TC) com meio de contraste e a ressonância magnética (RM) de encéfalo, que costumam evidenciar múltiplas lesões com hipossinal, com reforço do contraste, envolvendo gânglios da base e córtex cerebral. Conclusão: o desenvolvimento de novas técnicas e critérios de diagnóstico é imprescindível para a exclusão de outras doenças do SNC, principalmente o linfoma e leucoencefalopatia multifocal progressiva, que podem ser confundidas nas imagens, principalmente no caso de lesão única.

Introduction: toxoplasmosis is caused by a mandatory intracellular protozoan, Toxoplasma gondii. Domestic cats are definitive hosts while humans are intermediate. Usually T. gondii infection is asymptomatic and benign, but in immunocompromised individuals as AIDS patients, reactivation of chronic disease may occur. As HIV presents neurotropism, neurotoxoplasmosis is the predominant cause of neurological disorders in these patients. The clinical manifestations, especially the ones found in specific image exams such as tomography and magnetic resonance of the skull are the best form of diagnosis. Objective: in this context, it was analyzed the relevance of image diagnosis in the neurotoxoplasmosis in HIVpositive patients. Methods: it was made a systematic review of the scientific literature in databases such as: Bireme, Scielo, Medline, Google Scholar and Pudmed, for the following descriptors: Image Diagnosis, Neurotoxoplasmosis, AIDS Serodiagnostic, Magnetic Resonance and Computed Tomography. It was included in the selection: articles, theses, dissertations, atlases, books, websites and guides in Portuguese and English, published between 1977 and 2015. Results and discussion: it was observed that among the most commonly used image exams, Computed tomography (CT) was highlighted with contrast medium and magnetic resonance image (MRI) of the encephalon, which usually show multiple hypersignal lesions with contrast medium enhancement, involving basal ganglia and cerebral cortex. Conclusion: the development of new techniques and diagnostic criteria is essential for the exclusion of other CNS diseases, especially lymphoma and progressive multifocal leukoencephalopathy, which can be misunderstood in the images, especially in the case of a single lesion.

Neurotoxoplasmose em paciente imunocompetente: relato de caso / Neurotoxoplasmosis in an Immunocompetent Patient: Case Report

A toxoplasmose é uma doença causada pelo protozoário Toxoplasma gondii e é a principal causa de lesão com efeito de massa no sistema nervoso central (SNC) em pacientes imunodeprimidos, causando sintomas neurológicos significativos. Em pacientes imunocompetentes, a evolução clínica da toxoplasmose é habitualmente benigna e a infecção é, na maioria das vezes, assintomática. O diagnóstico da neurotoxoplasmose é presuntivo, baseado nos achados de tomografia computadorizada (TC) ou de ressonância magnética (RM), e emcasos inconclusivos, pode-se utilizar a biópsia cerebral estereotáxica. O paciente relatado apresentava lesões sugestivas de neurotoxoplasmose na RM de encéfalo, porém era imunocompetente, e a sorologia para neurotoxoplasmose era negativa para o IgM. Foi submetido então a biópsia estereotáxica como extensão de propedêutica. O presente trabalho visa, a partir do relato de um caso raro, discutir sobre as formas de diagnóstico e tratamento de uma infecção em paciente previamente sadio, cuja evolução foi benigna devido ao diagnóstico e tratamento precoces.

Toxoplasmosis is a disease caused by the protozoan Toxoplasma Gondii and is the leading cause of injury with mass effect on the central nervous system (CNS) in immunocompromised patients, that causes significant neurological symptoms. In immunocompetent patients, the clinical course of toxoplasmosis is usually benign and the infection is most often asymptomatic. The presumptive diagnosis of toxoplasmosis is based on findings of computed tomography (CT) or magnetic resonance imaging (MRI), and inconclusive cases, can use stereotactic brain biopsy . The reported patient had lesions suggestive of cerebral toxoplasmosis in brain MRI, but was immunocompetent and toxoplasmosis serology was negative for IgM. The, he underwent a stereotactic biopsy as an extension of workup. The present work aims, from a rare case description, discuss ways of diagnosing and treating an infection in a previously healthy patient whose evolution was benign diagnosis because early treatment.

Encefalite pós-toxoplasma após iniciação de terapia anti-retroviral de alta atividade / Toxoplasma encephalitis after iniciation of highly active anti-retroviral therapy (HAART)

Since 1983 Toxoplasma encephalitis (TE) is the neurological disorder most frequently found in HIV/AIDS patients. It commonly develops as a reactivation, and its etiological agent is the obligatory intra-cellular protozoan Toxoplasma gondii (T. gondii). The parasite seropositive rat, with varies in different parts of the world but is significatly high in most of then, is what keeps concern about TE constantly present. The first antiretrovirals favorate the same class and were used in single terapies; they were incapable of promoting sufficient immunological recovery to avoid opportunistic diseases and, furthermore, the concept of either primary or secundary prophylaxis had not been stablished at the time. In 1996 the apparence of two new antiretroviral classes triggered a new treatment concept. The existing prophylatic procedures were associated to a Highly Active Antiretroviral Therapy (HAART), a behavior that showed its efficacy in reducing the number of cases. Toxoplasma encephalitis has recently been described with an immune reconstruction inflammatory syndrome(IRS) related to the rapid response to HAART in severely immunodepressed individuals. Reports on reactivation or relapse noted in patients with sustained immunological recovery, when it is safe to suspend prophylaxis, suggest the participation of more agressive T. gondii strains or factors inherent to the host. It is therefore necessary to carry out more wide-ranging studies to clarify the link between parasite/host and chronic/reactivated infections of cysts. Other alternatives to the treatment and prophylaxis of AIDS and TE that facilitate the adhesion of the patient to the first approach, as well as the definition of the serological status for T. gondii and the adoption of prophylatic measures related to primary infection cases, can largely contribute to reduce the number of TE cases