Effect of high-dose dexamethasone on the outcome of acute encephalitis due to Japanese encephalitis virus.

Death due to Japanese encephalitis usually occurs in the first 5 days of hospitalization as a result of deepening coma with respiratory arrest. Death may result from edema-induced increases in intracranial pressure that might be reduced by the administration of steroids. Sixty-five patients presenting in Thailand to four hospitals with a diagnosis of acute Japanese encephalitis were randomized in a double-masked fashion and stratified by initial mental status into a placebo group (saline) or a treatment group (dexamethasone 0.6 mg/kg intravenously as a loading dose followed by 0.2 mg/kg every 6 h for 5 days). Fifty-five of the 65 had confirmed Japanese encephalitis as demonstrated by detection of virus or by Japanese encephalitis virus-specific IgM antibody. Important outcome measures included mortality (24%, treatment group; 27%, control group), days to alert mental status (3.9 vs. 6.2), and neurologic status 3 months after discharge (45% abnormal in each group). No statistically significant benefit of high-dose dexamethasone could be detected.