Implications of isolated white matter abnormalities on neonatal MRI in congenital CMV infection: a prospective single-centre study

Objective Investigating the clinical implications of isolated white matter abnormalities on neonatal brain MRI in congenital cytomegalovirus (CMV). Design Prospective, observational. Patients/interventions Two paediatric radiologists, blinded to clinical data, independently scored the white matter in 286 newborns with congenital CMV. After assessing interobserver variability, mean score was used to categorise white matter (normal, doubtful or abnormal). Patients with other brain abnormalities were excluded. Main outcome measures Hearing and neuromotor evaluation. Results Cohen's weighted kappa was 0.79 (95% CI 0.73 to 0.84). White matter was normal in 121 patients, doubtful in 62, abnormal in 28. Median clinical follow-up was 12.0 months (IQR 12.0-27.7 months). Neonatal hearing loss occurred in 4/27 patients (14.8%) with abnormal, 1/118 patients (0.8%) with normal and 1/62 patients (1.6%) with doubtful white matter (p<0.01). Impaired cognitive development was seen in 3/27 patients (11.1%) with abnormal, 3/114 patients (2.6%) with normal and 1/59 patients (1.7%) with doubtful white matter (p=0.104). Alberta Infant Motor Scale (AIMS) was below P75 in 21/26 patients (80.8%) with abnormal, 73/114 patients (64.0%) with normal and 36/57 patients (63.2%) with doubtful white matter (p=0.231). In a subgroup of patients with minimal clinical follow-up of 18 months, AIMS score was below P75 in 10/13 patients (76.9%) with abnormal, 13/34 patients (38.2%) with normal and 7/20 patients (35.0%) with doubtful white matter (p<0.05). Conclusions Abnormal white matter was associated with neonatal hearing loss and mild, lower motor scores. A tendency towards impaired cognitive development was seen. Patients with doubtful white matter did not show worse clinical outcome.