DETERMINING THE TIME BEFORE BIRTH WHEN ISCHEMIA AND HYPOXEMIA INITIATED CEREBRAL-PALSY

Objective: To test the hypothesis that lymphocyte and normoblast count s in neonatal blood can be used to identify the time that ischemia and hypoxemia produced cerebral palsy. Methods: Blood lymphocyte and norm oblast counts were analyzed at intervals after birth in 16 neonates fo r whom we knew the time when antenatal ischemic and hypoxemic brain da mage began. These counts were compared with counts from normal newborn s, infants with low Apgar scores and no cerebral palsy, and infants wi th cerebral palsy caused by developmental and other early gestational disorders. Results: Lymphocyte counts increased to more than 10,000/mm (3) and normoblast counts to 2000/mm(3) or more within 2 hours after t he brain-damaging ischemia and hypoxemia began. Lymphocyte counts retu rned to normal levels 24 hours after the damaging event took place, an d normoblast counts in 24-36 hours. Normal neonates had a mean +/- one standard deviation lymphocyte count of 4430 +/- 1418/mm(3) and a norm oblast count of 560 +/- 771/mm(3). Conclusion: Following the changing counts of lymphocytes and normoblasts in neonates' blood may accuratel y identify the time before birth when brain-damaging ischemia and hypo xemia began.