Cerebrovascular physiology in perinates with congenital hydrocephalus.

PURPOSE

This study investigated changes in regional cerebral blood flow (rCBF), autoregulation (AR), and mean CO(2) reactivity (CO(2)r) in nine neonates, who underwent cerebrospinal fluid (CSF) diversion for congenital hydrocephalus.

METHODS

During shunt insertion, a thermal diffusion probe inserted adjacent to the ventricular catheter in the right parietal region recorded rCBF. Changes in rCBF, mean arterial pressure, intracranial pressure (ICP), and expired CO(2) tension were recorded before and after removing CSF.

RESULTS

Mean baseline rCBF for the entire group was 19.5 mL/100 g/min (range 8.4-44.8), with a mean ICP of 9.9 mmHg (range 4-20). Following CSF removal, the rCBF increased significantly in two patients. Three patients demonstrated AR throughout their studies; one infant showed AR after CSF removal. One infant without AR during shunt insertion showed an increase in rCBF and AR during a revision 5 months later. Baseline CO(2)r varied considerably but was greater than two in two patients and increased in three other children after CSF removal. Mean follow-up was 23.6 months. One child, with severe developmental delay, died. Death or severe delay was associated with the absence of AR and a negative CO(2)r in three children. Normal or mild developmental delay was associated with AR and a neutral or positive CO(2)r in five patients.

CONCLUSIONS

Baseline levels of rCBF were not associated with developmental prognosis. AR and a positive CO(2)r were necessary but insufficient factors for normal development. The absence of AR and a negative CO(2)r were associated with poor prognosis.