Transcranial Doppler Sonography in Children

Abstract

The blood flow velocities in the basal cerebral arteries can be recorded at any age by transcranial Doppler sonography. By a standardized examination technique, the vessel identification is reliable even without visual control of the site of the sample volume. A stable state of vigilance is necessary to obtain constant recordings. Age has a tremendous influence on the flow velocities. The velocities increase rapidly during the first weeks and reach their maximum around the sixth year of life. The influence of carbon dioxide partial pressure, gestational age, birth weight, hematocrit, and vigilance on the velocities has to be considered. Heart rate and arterial blood pressure are relevant only in cases of extreme values. The clinical applications of transcranial Doppler sonography cover diseases like patent ductus arteriosus, perinatal brain damage, increased intracranial pressure, cerebral malformations, brain death, and stenoses and occlusions of main cerebral arteries. The technique is helpful for control of certain therapies. A continuous recording technique has also been developed for this purpose. Care should be taken in deriving a prognosis from Doppler recordings.

Cerebral Blood Flow Velocity During Occlusive Manipulation of Patent Ductus Arteriosus in Children

“…The fact that diastolic flow velocity of major intracranial vessels decreases with the presence of the ductal shunt suggests a failure of the cerebral circulation to decrease the resistance in distal cerebral vessels and to maintain flow velocity. 2 -5 • 7 Although low diastolic flow velocity in the middle cerebral artery of neonates or small infants might be related to large PDA shunts, this Doppler "sign" in some other pediatric patients has also been associated with increases in intracranial pressure, 5 impairment in cerebral venous drainage 13 • 14 or situations leading to low cardiac outputY Marked augmentation in the blood flow velocity of major intracranial vessels is expected after resolution of large shunts.…”

Transcranial doppler ultrasonography (TCD) in infants with sickle cell anemia: Baseline data from the BABY HUG trial

“…Velocities of the basal cerebral arteries have been found to be age dependent in healthy children with normal hemoglobin levels [1,11]. For example, the mean MCA velocity is low soon after birth (24 cm/sec) but increases rapidly during the first three months of life to 42 cm/sec, probably related in part to the physiologic anemia of infancy.…”

“…Subsequently, the mean MCA velocity rises slowly to 74 ± 14 cm/sec at 3–12 months of age and 85 ± 10 cm/sec between the ages of one and three years. The highest values occur between the ages of four and six years with peak MCA velocity approaching 100 cm/sec [11]. After that, velocities decrease linearly (mean MCA velocity 80 cm/sec at 10–18 years of age).…”

New Transcranial Doppler Index in Infants with Hydrocephalus: Transsystolic Time in Clinical Practice

“…The typical TCD velocity waveform has been described as a systolic acceleration and a gradual decline during diastole (Aaslid et al 1982;Bode and Eden 1989).…”