HIGHER NEONATAL CEREBRAL BLOOD-FLOW CORRELATES WITH WORSE CHILDHOOD NEUROLOGIC OUTCOME

Cerebral blood flow (CBF) in newborn infants is often below levels nec essary to sustain brain viability in adults. Controversy exists regard ing the effects of such low CBF on subsequent neurologic function. We determined the current childhood neurologic status and IQ in 26 subjec ts who had measurements of CBF performed with PET in the neonatal peri od between 1983 and 1989 as part of a study of hypoxic-ischemic enceph alopathy. Follow-up information at ages 4 to 12 years was obtained on all 26 subjects. Ten subjects had died. All 16 survivors underwent cli nical neurologic evaluation, and 14 also underwent intelligence testin g. Eight had abnormal clinical neurologic evaluations; eight were norm al. The mean neonatal CBF in those with abnormal childhood neurologic outcome was significantly higher than in those with normal childhood n eurologic outcome (35.64 +/- 11.80 versus 18.26 +/- 8.62 mL 100 g(-1) min(-1), t = 3.36, p = 0.005). A significant negative correlation betw een neonatal CBF and childhood IQ was demonstrated (Spearman rank corr elation r = -0.675, p = 0.008). Higher CBF was associated with lower I Q. The higher CBF in subjects with worse neurologic and intellectual o utcome may reflect greater loss of cerebrovascular autoregulation or o ther vascular regulatory mechanisms due to more severe brain damage.