Incidence. Prompt diagnosis and appropriate therapy are major challenges in the care of newborn patients (Volpe 2001). Of major clinical importance in new-borns are bacterial infections of the CNS, which are often associated with bacteremia, i.e., sepsis. Bacterial meningitis has an incidence of 0.3 per 1,000 live births, sepsis of 1.5 per 1,000 live births (Klein and Marcy 1995; Saez-Llorens and McCracken 1998). Meningitis is most commonly associated with group B streptococcus and Escherichia coli. The pathogenetic sequence runs almost invariably from bacteremia to meningitis. The bacteria are usually acquired during labor or delivery and are associated with infection of the maternal urinary tract and/or genitals.
Neuropathology. Acute changes associated with bacterial meningitis include arachnoiditis, cerebral edema, vasculitis, infarction, ventriculitis, and en-cephalopathy (Larroche 1975; Friede 1989). Among the chronic changes (Larroche 1975; Friede 1989) are hydrocephalus, multicystic encephalomalacia and
porencephaly or microcephaly, atrophy of the cortex and white matter as well as defects of cortical devel- 23.3.2
opment (Fig. 23.3). Abacterial Meningoencephalitis
Clinical Features. The first stage of disease is marked Although very rare in the industrialized world, in by symptoms of sepsis and respiratory disturbances. developing countries, especially Africa, other types
Neurological signs include seizures, stupor/irritabil- of infection are common in newborns and young ity, focal cerebral signs, bulging of the anterior fon- infants. This is especially true of acquired immuno-
tanel, extensor rigidity - opisthotonus. In cases of deficiency syndrome (AIDS). The ability of the hu-
late onset, the picture is dominated by the neurologi- man immunodeficiency virus (HIV) to be transmit-
cal signs. Meningitis must be suspected in all cases ted during pregnancy and its neurotropism are well involving sepsis and confirmed or excluded by labo- established (Price et al. 1988). CNS involvement in ratory evaluation. A bacteriogram can determine AIDS is characterized by progressive encephalopa-
which antibiotic will be most effective. Moreover, thy with cerebral atrophy, inflammatory infiltrates, sepsis caused by meningococci may lead to death multinuclear giant cells, and in some cases vascular without expression of a purulent meningitis. In those mineralization (Sharen et al. 1986). Opportunistic cases, the above-mentioned clinical symptoms may infections are uncommon in this age group.
exist but the diagnosis will be performed exclusively Children infected transplacentally may exhibit by microbiological examination of the blood. developmental abnormalities consisting of delayed acquisition and varying degrees of cognitive dysfunction (Epstein and Sharer 1988). Some may develop a progressive encephalopathy with neuro-
pathological features (Price et al. 1988) that are concordant with adult subacute encephalitis except for the pronounced vascular impairment with calcification of the basal ganglia.
Half of all cases of abacterial meningoencephali-tis exhibit prostaglandin medication-induced fresh cerebral hemorrhages at various localizations, and cerebellar heterotopias, which are regarded as a common finding in fetuses. One case was described with hypoxic-ischemic-type brain damage associated with recent periventricular hemorrhage, and comprised pronounced diffuse necrosis of both gray and white matter with diffuse gliosis, neuronal loss, macrophagic reaction, and rare calcifications (En-cha-Razavi et al. 1991).
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