Cytomegalovirus Infection
Cytomegalovirus (CMV) is usually transmitted to the fetus during a primary maternal infection. Fetuses of women with preexisting seroimmunity are usually protected. Central nervous system involvement occurs with infection in the first and second trimester of pregnancy.
Microcephaly and seizures are common manifestations of congenital cytomegalovirus infection. Microcephaly and seizures result from brain damage due to meningoencephalitis in the developing brain (Figure 277.1 [A]). Cytomegalovirus meningoencephalitis produces damage to the fetal brain due to its destructive effects on the proliferating and migrating neurons. Cytomegalovirus is associated with several migrational disturbances including polymicrogyria (most frequent), lissencephaly, pachygyria, and neuronal heterotopias. Central nervous system manifestations of CMV infection also include porencephaly, hydranencephaly, hydrocephalus, and cerebellar hypoplasia.
Neurological signs are the sole manifestations of congenital CMV infection in about 30% of cases. Neonates with congenital CMV infection often have hepatomegaly, petechiae, or other manifestations of reticuloendothelial system involvement. Chorioretinitis also occurs. Computed tomography of the brain often shows periventricular calcifications (Figure 277.1[B]).

A	B

Figure 277.1— [A] Microcephaly. [B] Computed tomography of the brain showing evidence of periventricular calcifications.

MRI and CT may also show evidence of deep white matter lesions specially in the anterior part of the temporal lobe (Figure 277.2). Calcifications may not be present.

Figure 277.2.— CT of the brain demonstrating white matter temporal lobe lesions. B. MRI (flare) demonstrating anterior symmetrical temporal lesions. C. MRI of the brain demonstrating an anterior temporal lobe porencephalic areas.