Meningoencefalitis herpética: ¿cuándo sospecharla? / Herpetic meningoencephalitis: a review

La encefalitis herpética (EH) secundaria a la infección por el virus de herpes simple 1 (VHS1) es la causa conocida más frecuente a nivel mundial de infección viral fatal del sistema nervioso central (SNC). La agresividad de su curso clínico y la morbilidad asociada a su desarrollo obligan a todo médico generalista a mantener una alta sospecha clínica para lograr su diagnóstico. Ciertas manifestaciones clínicas como la fiebre asociada a alteraciones en el sensorio o a alteraciones en el comportamiento de un paciente o a ambas posibilidades se presentan en un porcentaje superior al 90% de los casos confirmados. La solicitud en el líquido cefalorraquídeo (LCR) de la reacción en cadena de la polimerasa (PCR) para el VHS1 es el estudio complementario de laboratorio que posee la mayor sensibilidad y especificidad para confirmar el diagnóstico de EH. A su vez, la resonancia nuclear magnética (RNM) es el estudio de imagen que posee mayor sensibilidad y especificidad para el diagnóstico de la enfermedad. La EH secundaria al VHS1 es, de las infecciones virales que afectan el SNC, la única que posee tratamiento específico. La instauración temprana de tratamiento con aciclovir disminuye la mortalidad asociada al desarrollo de la enfermedad de un 70% y sin tratamiento, hasta un 10-20%. El objetivo principal de esta revisión es señalar las diversas situaciones clínicas en las cuales se debe sospechar la EH así como guiar la correcta utilización de los estudios complementarios e instaurar de manera temprana el tratamiento para reducir al máximo la morbimortalidad. (AU)

The herpes simplex virus type 1 (HSV1) encephalitis (EH) is the most common known cause of sporadic fatal encephalitis worldwide. The fatal consequences in the development of this disease and the morbidity related to it, should alert general practitioner to be always aware of its possible diagnosis. Clinical features such as fever associated with altered mental status or disturbances in the level of consciousness are present in more than 90% of confirmed cases. The analysis of the polymerase chain reaction (PCR) for HSV1 in central nervous system (CNS) fluid is the laboratory study of choice for establishing the diagnosis with the best sensitivity and specificity. Moreover, magnetic resonance image (MRI) is the most sensitive and specific imaging study for the detection of this entity. The VHS1 EH is one of the few treatable viral infection of the central nervous system to date. Hence, early administration of adequate antiviral therapy with Acyclovir remains paramount. The early administration of empiric therapy can decrease the mortality rate from 70% without treatment to 10-20% in confirmed cases. We sought to describe the disease's clinical features, and to further discuss the accurate use of diagnostic tools and treatment strategies in order to reduce the high related morbi-mortality. (AU)

Encefalitis herpética, métodos diagnósticos / Herpetic encefalitis, diagnostic methods

La encefalitis herpética es un tipo de encefalitis asociada al virus del Herpes Simple (VHS), es una enfermedad grave del sistema nervioso central. El objetivo de este estudio es realizar un análisis de los diferentes métodos diagnósticos de encefalitis herpética. Caso Clínico: paciente femenina de 45 años de edad, con antecedentes personales patológicos negativos; al momento del ingreso presenta cuadro agudo de cefalea, fiebre, alteraciones de conciencia y confusión mental. Con el diagnóstico de ingreso de meningitis bacteriana, previo a su traslado desde el Hospital de San Lorenzo al Hospital Escuela Universitario, fue tratada con antibióticos e ingresada a la sala de mujeres de medicina interna. A las 72 horas no presentó mejoría con los antibióticos administrados y se agregó vancomicina, al tiempo que presentó una crisis convulsiva tónico-clónica, por lo que se realizó punción lumbar encontrándose líquido cefalorraquídeo con predominio de linfocitos, no sangrado, glucorraquia normal, proteinorraquia normal. La Resonancia Magnética (RM), reveló características de encefalitis herpética, diagnostico apoyado por el estudio electroencefalográfico. Confirmado el diagnóstico de encefalitis herpética con los exámenes realizados, se inició tratamiento con aciclovir, con lo que la paciente evolucionó de manera satisfactoria y su única secuela fue disfasia. Conclusión: La RM demostró encefalitis herpética, constituyéndose como el estudio de elección, consensibilidad de 90%-100%, en tanto que la sensibilidad del electroencefalograma es de 84% y la especificidad de 32%. En circunstancias especiales, para realizar el diagnóstico, se puede utilizar la RM junto a la reacción en cadena de polimerasa para herpes, al ser ambas de muy alta sensibilidad...(AU)

[Herpes simplex virus encephalitis during immunosuppressive treatment of ulcerative colitis]

Today, with the advent of new medications, treatment of Ulcerative colitis [UC] has been markedly improved. Immunosuppressive drugs used in therapy predispose patients to opportunistic infections. A 22-year-old woman was admitted to emergency department due to acute exacerbation of UC and decreased level of consciousness. She was under treatment with 5-aminosalicylate, prednisolone and azathioprine. In neurological evaluation, patient had cerebral herniation. Non-contrast CT scan revealed multiple hemorrhagic areas in both frontal lobes. Right frontal craniotomy was performed emergently. Histopathologic evaluation of brain tissue was reported as "Herpes simplex encephalitis". Polymerase chain reaction [PCR] assay was also positive for HSV DNA. Immunosuppressive drugs such as azathioprine have a pivotal role in the treatment of resistant and/or severe cases of UC. Prevalence of infectious complications was reported to be 7.4%, 1.8% of which were severe [including herpes zoster encephalitis] .Our review of literature indicates that no case of herpes simplex encephalitis following immunosuppressive therapy for UC has been reported

acyclovir responsive herpes simplex encephalitis definition of its radiological features; correlation with the clinical picture and CSF analysis

In the present study 13 patient with the clinico- radiological diagnosis of herpes simplex encephalitis [HSE] are included. All patients were subjected to [1] full clinical examination [2] CSF analysis that included CSF chemistry [protein, glucose and chloride], cells, latex test for bacterial antigens, CSF culture of pyogenic bacteria and TB and PCR [polymerase chain reaction] for detection of both type I and type II herpes simplex virus [HSV] DNA [3] Both MRI and CT scan of the brain with and without contrast were done to all patients. CSF analysis showed moderate rise of proteins [average 860 mg/dl, normal values up to 450 mg/dl] with normal sugar and glucose and with a predominately lymphocytic pleocytosis in all patients. Latex test was negative for all patients. Both CSF bacterial and TB cultures were eventually negative. HSV type I DNA was detected in the CSF by the PCR test in all patients, type II HSV DNA was not detected in the CSF of any of the patients examined. Involvement of the temporal lobes unilaterally or bilaterally were the cardinal radiological feature demonstrated in all patients. Other areas of the brain, such as the orbital frontal region, the paraventricular region, the basal ganglia or the brain stem, are involved but less frequently. The significance of these findings for the early diagnosis of herpes encephalitis are discussed. Also the clinical course of the patients and their response to treatment will be presented and discussed