FIELD: medical diagnosis. SUBSTANCE: method involves making an electroencephalogram at rest on the 7th and 21st days after falling ill, determining average frequency of prevailing bioelectrical activity in occipital- sencipital leads, and comparing this index with its normal value for the given age group, calculating the frequency index for the given age group correlating with the final neurological outcome of the disease. EFFECT: higher accuracy of forecasting the consequences of acute meningitis and encephalitis. 1 tbl
