Calcifications of the carotid siphon--a common finding in infancy and childhood.

In the tortuous sigmoid segment of the internal carotid artery (`carotid siphon') which is located in the base of the skull, calcific deposits have been shown macroscopically in all 22 children of this series aged 1 to 16 years who died after accidents (11 cases), or after various diseases of a short or longer duration (5 and 6 cases, respectively). The calcific incrustations appear first and become most pronounced in the upper part of the carotid siphon, i.e. above the orifice of the ophthalmic artery. In half the cases calcifications were grossly visible in the orifice and proximal segment of this artery as well. Microscopically, the calcific deposits represent incrustations of the subintimal internal elastic layers and adjacent media. The local and general factors probably responsible for these early arterial calcifications and the possible prospective significance of these lesions are discussed.