A 2-year-9-month-old male was referred to neurology for evaluation of global developmental delay and microcephaly. He was born full term with uncomplicated pregnancy and delivery. However, his head circumference was 32 cm (below 3rd percentile for age) and his birth weight was 3060 g (below 50th percentile). Postnatal blood testing confirmed the diagnosis of congenital cytomegalovirus (CMV) infection. Auditory evoked potentials detected sensorineural hearing loss. He received oral valganciclovir for 6 months. At the time of neurological examination, his head circumference was 44 cm (below first percentile), and he could not sit by himself. He had truncal hypotonia and spastic quadriparesis, right greater than left. He also demonstrated generalized hyperreflexia and bilateral upgoing plantar responses.

Head ultrasound at 5 weeks showed abnormal gyration, diffuse white matter signal abnormality, and a left germinolytic cyst ( Fig. 14.1 ).

Congenital CMV. Coronal head ultrasound shows shallow sylvian fissures, diffuse white matter hyperechogenicity, and left germinolytic cyst. CMV , Cytomegalovirus.

MRI showed diffuse white matter T2 abnormalities and migrational defects with abnormal cortical sulcation and gyration ( Fig. 14.2 ).

Congenital CMV. Brain MRI, (A) sagittal T2 and (B and C) axial T2 MRI at 5 months and (D) axial T2 MRI at 23 months show shallow Sylvian fissures with extensive polymicrogyria and diffuse white matter abnormalities that decrease with progressive age and myelination. CMV, Cytomegalovirus.

Congenital CMV infection is defined by the presence of clinical and/or biological signs with supportive findings at neuroimaging. The most frequent neonatal signs are hepatosplenomegaly (60%), microcephaly (53%), jaundice (67%), petechiae (76%), and at least one neurological abnormality (68%). Laboratory abnormalities include increased liver transaminases (83%), thrombocytopenia (77%), hyperbilirubinemia (69%), hemolysis (51%), and elevated cerebrospinal fluid proteins (46%). Imaging abnormalities are present in 70% of symptomatic newborns, with intracerebral calcifications being the most commonly described feature.

Causes of microcephaly include perinatal toxoplasmosis, rubeola, CMV, herpes simplex (TORCH) infections; some genetic syndromes; and maternal toxins such as alcohol, tobacco, drugs, or antiepileptics.

MRI in congenital CMV shows periventricular calcifications, white matter abnormalities, and ventriculomegaly. Polymicrogyria is the most frequently associated cortex abnormality.

Congenital toxoplasmosis can produce a similar appearance, though with more diffuse cerebral calcifications and less common polymicrogyria.

Bilateral cerebral palsy (CP) and sensorineural hearing loss, due to congenital CMV infection.