RECURRENT INFECTIONS bouts of meningitis are most frequently related to remote as well as to recent head trauma. The individual episodes are usually caused by the same bacterial species that are also-created with meningitis occurring in the absence of trauma. except that pneumococci of higher serologic types are isolated more commonly thanH. influenzae and Neisseria. Bouts of meningitis may be separated by an interval of several years.
Cerebrospinal fluid rhinorrhea owing to a defect in the cribriform plate is often associated with recurrent meningeal infection. All patients with repeated bouts of meningitis should be subjected to a vigorous search for. communication between the subarachnoid space and the nasopharynx, and if roentgenographic techniques fail to disclose the defect, craniotomy should be considered. Other situations predisposing to recurrent meningeal infections include chronic mastoiditis or Petros-is, congenital abnormalities of the cranial vault, and congenital dermoid sinus tracts.
Ventricular mastoid shunts aimed at relief of hydrocephalus are also complicated by recurrent infections, which are often heralded by otitis media. Recurrent bouts of meningitis have been reported in children who have undergone splenectomy; this does not appear to be true of adults. Nor is there evidence that the incidence of meningitis is increased in children with hypo- or dysgamma insulinemia.
INFECTIONS WITH MULTIPLE ORGANISMS
Meningitis caused by two or more organisms occasionally occurs in infants, young children and neonates, who may develop brain abscesses following surgery or birth trauma. H. influenzae is usually one of the organisms and has been found in conjunction with N. meningitides, D. pneumoniae, group A Streptococcus and E. coli. In adults infections with multiple organisms most commonly follow rupture of a brain abscess into the subarachnoid space, and streptococci, staphylococci, and gram-negative enteric pathogens may all be isolated from the same specimen of cerebrospinal fluid.