Popis: |
Congenital lymphocytic choriomeningitis virus (LCMV) infection is a transient intrauterine viral infection with selective teratogenicity depending on the timing of the primary maternal infection. LCMV is cleared from the body of the fetus after the acute phase of illness and, in most cases, has lost its virulence at the time of birth. LCMV competes with extracellular matrix proteins for its tropism toward heavily glycosylated alpha-dystroglycan. In the first trimester, while tropism toward heart myoblasts is high, intrauterine infection (IUI) can lead to miscarriage or fetal demise. Later in pregnancy, LCMV becomes neurotropic with tropism toward retina and brain. Most often systemic symptoms are subtle or absent at the time of birth. The timing of the IUI determines the neuroteratogenic phenotypes of congenital LCMV infection. IUI that occurs early during gestation can lead to isolated cerebellar dysgenesis and hypoplasia. When IUI occurs during neural radial migration, echoencephalography shows defective cerebral opercularization, intracranial calcifications at the gray-white matter junction, enlarged extra-axial subarachnoid space, and cortical dysplasia. When IUI occurs after the completion of insular opercularization (late second trimester), echoencephalography shows extensive cystic periventricular leukomalacia with bi-occipital porencephaly and mild defects in gyrogenesis. A late gestation IUI induces aseptic LCMV meningitis with occlusion of the aqueduct of Sylvius, leading to congenital obstructive hydrocephalus. Congenital LCMV remains underdiagnosed as clinical manifestations are predominantly neurologic. As echoencephalography remains the preferred screening strategy for detecting neonatal central nervous system pathology, prior knowledge of echoencephalography of congenital LCMV may facilitate its recognition, prompting a serological evaluation. |