Cerebellar Malformations in Congenital Cytomegalovirus Infection

BACKGROUND AND PURPOSE: Congenital cytomegalovirus (cCMV) is the leading infectious cause of birth defects in the United States; its spectrum of MRI findings is broad, with cerebellar abnormalities scarcely reported in the literature. We aim to describe the neuroimaging spectrum of cerebellar anomalies and malformations in patients with cCMV infection and their associations with other typical cCMV findings in prenatal and postnatal brain MRI. METHODS: We conducted a single-center retrospective observational study at a quaternary children’s hospital. Included patients had fetal and/or postnatal brain MRI and confirmed congenital cCMV infection. Age-matched controls were also analyzed. Two neuroradiologists evaluated cerebellar morphology on fetal and postnatal brain MRIs; one determined cerebellar size and documented other common cCMV imaging features. Statistical analyses included paired t-tests, Cohen’s d, McNemar’s, and Chi-square tests, with inter-rater reliability assessed by Cohen’s Kappa and Phi coefficient. RESULTS: Seventy-two MRIs (64 patients) were included from 36 CMV+ and 36 controls. In the CMV+ group, 17 MRIs (47.2%) were fetal (median gestational age: 30 weeks [IQR: 23-33.6]), and 19 (52.8%) were postnatal (median age: 4.23 months [IQR: 0.36-11.89]). Eight patients underwent both fetal and postnatal imaging. Cerebellar hemisphere and vermian dysmorphology were seen in 10 fetal MRIs (58.8%). Postnatally, the cerebellar hemispheres were abnormal in 11 (57.9%) MRIs, and the vermis in 9 (47.4%), with dysfolia/dysplasia being the most prevalent malformation (57.9% and 47.4%, respectively). Interrater reliability for identifying cerebellar abnormalities showed moderate agreement (kappa=0.665). Vermis height (p=0.02) and anteroposterior diameter (p