ASEPTIC-MENINGITIS IN INFANTS YOUNGER THAN 2 YEARS OF AGE - ACUTE ILLNESS AND NEUROLOGIC COMPLICATIONS

Objective. We report the clinical features and cerebrospinal fluid (CS F) laboratory values for 277 children younger than 24 months of age wi th aseptic meningitis who were prospectively evaluated at three Baltim ore hospitals between July 1986 and December 1990. A major objective w as to define the incidence, etiology, and outcome of neurologic compli cations occurring during the acute illness. Methods. Cases were identi fied by surveillance in the ambulatory care departments of each of the three hospitals, pertinent historical and clinical data were obtained by interview of the parents and by review of the medical records, ini tial CSF laboratory values were recorded, and appropriate specimens we re submitted to determine the viral etiology. A subset of 216 children who participated in a long-term natural history study were followed p eriodically with neurologic examinations and formal neurodevelopmental testing. Results. Most cases occurred in very young infants; 63.5% of patients were 8 weeks of age or younger, and 84.1% were younger than 16 weeks of age. In this very young cohort, the dominant symptoms were fever and irritability; only 8.7% had evidence of meningeal irritatio n at the initial examination. The acute illness was complicated by eit her complex seizures, physical evidence of increased intracranial pres sure, or coma in 25 (9.0%) cases. Within the age group under study, th ese complications were each significantly more likely to occur in pati ents older than 12 weeks of age than in younger infants. The risk of n eurologic complications was similar among infants infected with group B coxsackieviruses and echoviruses, the two major enterovirus classes observed to cause disease. Acute central nervous system (CNS) complica tions could not be correlated with extremely abnormal CSF laboratory i ndices. Importantly, there was no risk of long-term neurologic sequela e attributable to acute CNS complications. Conclusions. While approxim ately 9% of infants and children younger than 2 years of age with asep tic meningitis experience acute CNS complications in the form of compl ex seizures, increased intracranial pressure, or coma, the prognosis f or long-term cognitive development appears to be as favorable as the p rognosis for children with aseptic meningitis who do not experience th ese complications.