Subdural effusion and its relationship with neurologic sequelae of bacterial meningitis in infancy: a prospective study.

One hundred thirteen infants, aged 1 to 18 months, were screened systematically and serially using transillumination for the presence of subdural effusion during acute bacterial meningitis due to Haemophilus influenzae type b, Streptococcus pneumoniae, or Neisseria meningitidis. Effusion developed in 44 (39%) of the patients during the course of treatment. Young age, rapid onset of illness, low peripheral white blood cell count, and high cerebrospinal fluid levels of protein and bacterial antigen were associated with a higher likelihood of developing effusion. Although patients with effusion were more likely to have neurologic abnormalities both at the time of admission and at completion of therapy, and were more likely to have seizures during the course of treatment, there was no greater incidence of seizures, hearing loss, neurologic deficits, or developmental delay on longterm follow-up (median follow-up interval 5.5 years) in patients with effusion. Specific invasive therapy is not indicated in infants with meningitis and subdural effusion who are otherwise improving.