Cerebral blood flow velocity asymmetry, neurobehavioral maturation, and the cognitive development of premature infants across the first two years

OBJECTIVE: Premature infants are at risk of adverse developmental outcomes even with no demonstrable neurological damage. Neonatal physiological measures that can serve as indicators of later development are therefore important for early evaluation and intervention. METHODS: We followed the development of 51 low birth weight, premature infants across the first 2 years. Mean systolic cerebral blood flow velocity (CBFV) in the left and right middle cerebral arteries was measured at 37 weeks gestational age, neurobehavioral maturation was assessed with the Neonatal Behavior Assessment Scales (NBAS), and cognitive development was evaluated at 6, 12, and 24 months. RESULTS: Different patterns emerged for CBFV in the right versus left middle cerebral artery. Greater absolute values of right systolic CBFV were related to poorer performance on the habituation and orientation scales of the NBAS, whereas greater left systolic CBFV absolute values were related to better Mental Development Index (MDI) scores at 24 months. Right systolic CBFV asymmetry was related to poor neonatal orientation and low MDI score at 24 months. On the other hand, infants with left systolic CBFV asymmetry showed a more rapid increase in cognitive skills from 12 to 24 months and better cognitive performance at 2 years. CONCLUSION: Measurement of systolic CBFV in the neonatal period may assist in identifying infants at risk of poor developmental outcome.