[Pulsed Doppler sonographic determination of absolute flow velocities in the anterior cerebral artery in infants with hydrocephalus in comparison with a healthy patient sample]

Abstract

In 52 infants (weight: 3174 +/- 1165 g; gestational age: 41.3 +/- 6.5 weeks) with hydrocephalus pulsed doppler recordings were obtained in the anterior cerebral arteries. For comparison 52 healthy infants (weight: 3148 +/- 1118 g; gestational age: 40.6 +/- 5.7 weeks) were investigated. In all children the maximal systolic velocity, the end-systolic velocity, the end-diastolic velocity and the pulsatility-index were measured. In the healthy control group the maximal systolic velocity was 43 +/- 14 cm x s-1, the end-systolic velocity 20 +/- 8 cm x s-1, the end-diastolic velocity 11 +/- 5 cm x s-1 and the pulsatility index was 0.75 +/- 0.10. All 9 children with minimal ventricular dilation without progression showed normal flow profiles with normal flow velocities and pulsatility-index in the anterior cerebral arteries. 17 infants with moderate, slowly progressive ventricular enlargement showed significant increase of the maximal systolic velocity (60 +/- 27 cm x s-1) and the pulsatility-index PI (0.82 +/- 0.14). There was no difference in the end-systolic and end-diastolic velocities to the healthy control group. 26 children with marked and rapid progressive hydrocephalus showed significant decrease of the end-systolic and end-diastolic velocities and an increase in the pulsatility-index. The end-systolic velocity was 15 +/- 7 cm x s-1, the end-diastolic velocity was 4 +/- 7 cm x s-1 and the pulsatility-index measured 0.91 +/- 0.18. There was no difference in the maximal systolic velocity which measured 41 +/- 17 cm x s-1. All children with increased intracranial pressure showed a pathological flow profile with a decrease of diastolic forward flow. Absent or retrograde diastolic flow in rapid progressive hydrocephalus may lead to a decrease of brain perfusion resulting in hypoxemic ischemic brain lesions. After implantation of a ventriculo-atrial shunt an increase in the end-systolic and end-diastolic velocities and a decrease of the pulsatility-index could be shown. Shunt insufficiency can be shown early by a decrease in diastolic forward flow.