ABSTRACT
La encefalitis por el virus de Saint Louis es una enfermedad que se transmite a través de mosquitos de la especie Culex.En Argentina, se registran casos esporádicos, habitualmente asintomáticos en niños. Se presenta el caso de una paciente con manifestaciones clínicas inusuales en edad pediátrica y lesiones en el sistema nervioso central no descritas hasta el momento en la literatura. Se trata de una niña de 8 años, que consultó por síndrome febril, cambios conductuales, ataxia, clonus y rigidez de nuca. En el líquido cefalorraquídeo, se detectó pleocitosis predominantemente mononuclear. Se realizó una resonancia magnética, que evidenció imágenes de isquemia bitalámica. La infección por virus de Saint Louis se diagnosticó por IgM en el suero y el líquido cefalorraquídeo. La paciente evolucionó de manera favorable. Al momento del egreso hospitalario, persistía con bradipsiquia y alteraciones conductuales y se recuperó definitivamente 45 días después del alta.
Saint Louis encephalitis is transmitted by Culex mosquitoes. In Argentina sporadic cases are registered. Symptomatic illness is unusual in children. We present a case of meningoencephalitis caused by an uncommon viral infection. The clinical signs and symptoms are unusual for pediatric patients and the bilateral thalamic compromise showed on magnetic resonance has not been described previously. An 8-year-old girl consulted due to fever, behavior disorders and ataxia. Clonus and neck stiffness were detected at physical exam. Cerebrospinal fluid revealed mononuclear leukocytosis; bilateral ischemic compromise was observed in thalamus by magnetic resonance. Saint Louis virus was confirmed by serology: serum and cerebrospinal fluid IgM were positive during the acute phase of the disease and serum IgG was positive four weeks later. Most of the signs and symptoms of the disease were resolved, however mild behavior disorders were observed as acute sequelae up to 45 days after hospital discharge.