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)

A Case of Acute Retinal Necrosis Following Herpes Simplex Virus (HSV) Encephalitis

PURPOSE: To report a case of unilateral acute retinal necrosis (ARN) following herpes simplex virus (HSV) encephalitis. CASE SUMMARY: A 19-year-old man previously diagnosed with HSV encephalitis presented with a headache and visual loss in his left eye. On the initial visit, slit-lamp examination showed conjunctival injection and inflammatory cells (3+) in the anterior chamber of the left eye. Funduscopic examination showed optic disc swelling, multiple yellow-whitish spots in the peripheral retina and retinal vascular sheathing. After the patient was diagnosed with ARN, intravenous acyclovir (1,500 mg/m2/day) was administered. Because retinal detachment and multiple retinal breaks were found during the treatment period, the authors performed barrier laser treatment in the peripheral retina. At that time, no retinal necrosis was observed in the patient's right eye. The retinal lesions regressed, and no new retinal lesion was observed in the left eye, during the follow-up period. CONCLUSIONS: We report a case of ARN in a patient with HSV encephalitis. Ophthamologist should perform a thorough ophthalmic examination in a patient diagnosed with HSV encephalitis.