Cerebrovascular physiology in perinates with congenital hydrocephalus

This study investigated changes in regional cerebral blood flow (rCBF), autoregulation (AR), and mean CO₂ reactivity (CO₂r) in nine neonates, who underwent cerebrospinal fluid (CSF) diversion for congenital hydrocephalus.

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 CO₂ tension were recorded before and after removing CSF.

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 CO₂r 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 CO₂r in three children. Normal or mild developmental delay was associated with AR and a neutral or positive CO₂r in five patients.

Baseline levels of rCBF were not associated with developmental prognosis. AR and a positive CO₂r were necessary but insufficient factors for normal development. The absence of AR and a negative CO₂r were associated with poor prognosis.