Periventricular calcifications are not pathognomonic of cytomegalovirus. Periventricular calcifications occur because CMV has a predilection for the germinal matrix tissue, causing necrosis of the ependyma. Migration errors are best diagnosed by MRI of the brain. The diagnosis of congenital CMV central nervous system infection is established by detecting CMV DNA in urine by polymerase chain reaction or CMV-specific IgM detection. Placentitis should be present on pathological evaluation. Brain auditory evoked potentials should be performed in all neonates suspected of CMV exposure. Sensorineural hearing loss may be the sole manifestation of congenital CMV infection. Sensorineural hearing loss may be progressive.
Ganciclovir has been used to treat congenital central nervous system CMV infection. It does not change neurological outcome, since most damage is done prior to birth. Ganciclovir may prevent progression of sensorineural hearing loss.

Toxoplasmosis
Congenital toxoplasmosis is produced by Toxoplasma gondii. This protozoan parasite is more likely to cross the placenta in the last trimester of pregnancy; nevertheless, central nervous system and ocular manifestations are more frequent in fetuses infected during the first trimester. Microcephaly may occur in neonates with central nervous system toxoplasmosis infection but macrocephaly due to hydrocephalus as a result of aqueductal stenosis may also occur. Seizures often occur. Toxoplasmosis produces parenchymatous and periventricular calcifications (Figure 278.1). Porencephaly and hydranencephaly may also occur. Cerebrospinal fluid pleocytosis is often present.

Figure 278.1.— Computed tomography of the brain in a neonate with toxoplasmosis demonstrating many intraparenchymal and periventricular calcifications.

Chorioretinitis is present in most neonates with central nervous system involvement (Figure 278.2). Chorioretinitis is usually bilateral and involves the macular region. Hepatomegaly, hyperbilirubinemia, and anemia are systemic manifestations of congenital toxoplasmosis.

Figure 278.2.— Typical appearance of toxoplasma chorioretinitis.