Significance of intracranial bruits in neonates, infants, and young children.

In a control group an intracranial bruit (ICB) was heard in 4 of 13 children aged between 4 months and 3 years, but in none of 43 younger infants between the ages of one day and 4 months. In a group of 70 infants with cardiac murmurs of intensity grade III/VI or more, 19 of 30 aged between 4 months and 3 years had an ICB, compared with 4 of 40 younger infants aged between one day and 4 months (P less than 0.0005). It is concluded that in infants under the age of 4 months, even in the presence of a loud cardiac murmur, an ICB is rarely heard. The presence of an ICB, with or without signs of cardiac failure, strongly suggests an intracranial arteriovenous fistula.