Which Preemies need MRI exams?

Objective. To examine the relationship between very preterm infant neurobehavior at term and concurrent magnetic resonance-defined cerebral abnormalities.

Study design. 168 very preterm infants (birth weight <1250 g or gestation <30 weeks) were examined at term with 2 standardized neurobehavioral assessments, the Revised Hammersmith Neonatal Neurological Examination and the Neonatal Intensive Care Unit Network Neurobehavioral Scale. The relationship between composite neurobehavioral scores and qualitative white and gray matter abnormalities on magnetic resonance imaging was determined.

Results. Poorer neurobehavioral performance related to magnetic resonance-defined cerebral abnormalities. Composite neuro-behavioral scores related to the total grade of white matter abnormality, and worse neurobehavior related most strongly to 2 components of this grade: white matter signal abnormalities and reduction in white matter volumes. Neurobehavior was not related to the total grade of gray matter abnormality. However, delayed gyral maturation, a component of the total gray matter grade, was related to poorer performance on both neurobehavioral scales.

Conclusion. Very preterm infant neurobehavior at term is related to concurrent cerebral abnormalities in both white and gray matter defined by qualitative magnetic resonance imaging.

Comments. Brain MRI imaging of extremely premature infants as they reach term gestation is becoming a common practice to screen for periventricular leukomalacia and other lesions of the white or grey matter. In this study, 16% if study infants had moderate-severe white matter abnormalities, and 22% had abnormalities of grey matter on MRI. Babies with MRI abnormalities did significantly worse on neurobehavioral testing. Do all ELBW infants need MRI screening? I hope not. These tests are very costly, and it is unclear how we should deal with the results. Perhaps these neurodevelopmental tests will provide a way to screen ELBW infants to identify a sub-group in whom MRI imaging is warranted. ABK