Reduced occipital fractional anisotropy on cerebral diffusion tensor imaging in preterm infants with postnatally acquired cytomegalovirus infection.

Background: Detection of white matter (WM) abnormalities on MRI is important regarding the neurodevelopmental outcome in preterm infants. The long-term neurodevelopmental outcome of preterm infants with postnatal cytomegalovirus (CMV) infection has not been studied extensively.

Objectives: We aimed to assess WM microstructure in preterm infants with postnatal CMV infection using diffusion tensor imaging.

Methods: Infants <32 weeks' gestational age (GA) admitted to our hospital between 2007 and 2010, who had cerebral diffusion tensor imaging at term-equivalent age (40 weeks' GA) were included. CMV PCR in urine collected at term-equivalent age was performed to diagnose postnatal CMV infection. Congenital infection was excluded. In the frontal, parietal and occipital WM mean diffusivity, fractional anisotropy (FA), radial and axial diffusivity were calculated. Neurodevelopmental outcome was assessed at 16 months' corrected age using Griffiths' Mental Developmental Scales.

Results: Twenty-one postnatally infected and 61 noninfected infants were eligible. Both groups were comparable regarding GA, birth weight and age at MRI. There was a significant difference in median FA of the occipital WM between infected and noninfected infants (0.13 [IQR 0.11-0.16] versus 0.16 [IQR 0.14-0.18], p = 0.002). There were no differences in short-term neurodevelopmental outcome between infected and noninfected infants.

Conclusions: A significantly reduced FA suggests microstructural changes in the occipital WM of postnatally infected infants. These microstructural changes do not appear to result in impaired neurodevelopmental outcome at 16 months' corrected age.