Encephalitis: Which are and how to treat? Encefalitis: ¿cuáles y cómo tratar?

Abstract

Viral infections, the main cause of encephalitis, invade CNS via bloodstream (e.: enterovirus), peripherical nerves (e.: rabies) and less frequently, via olfactory nerve (e.: free life amoebas). Focal neuron compromise explains symptomatic variability. In Chile no one virus predominates largely and epidemiological or clinical characteristics may confuse initially. Herpes simplex encephalitis is a neurological emergency which obligates an early diagnosis to initiate specific treatment. Herpes simplex type 1 is important in children and adults and type 2 in the neonate. Isolation of herpes simplex in CSF is scarce, PCR has about 91% sensibility and high specificity continuing positive until five or seven days after sympomatology and/or treatment have started. Electroencephalogram is sensitive but unspecific. Magnetic resonance image is the most useful image diagnosis in the early acute stage of disease; CT scan allows to control the evolution. Cerebral biopsy is reserved for patients wit