The Paleoneurology Group at the Centro Nacional de investigación sobre la evolución Humana (CENIEH), led by Emiliano Bruner, has published a study today in the Journal of Anatomy which assesses vascular traits of the skull in individuals with craneosynostosis, a condition in which the sutures fuse prematurely, and the consequences for the vascular development of the cranial cavity.

These sutures separate the cranium bones and, in the course of their growth and development, they regulate the spatial relationships with the brain, ensuring that the bones can be molded to cater for the anatomical changes in its size and shape. Craneosynostoses are relatively frequent defects in the normal development of the skull, and they can have mild or serious effects, depending on the case, but they can block the growth of the skull cavity or constrain the development of the internal tissues.

This study considered the types of craneosynostosis that can produce an elongated skull (dolichocephaly) and those leading to a more rounded shape (brachycephaly), and analyzed how the condition affects the anatomy of the blood vessels in the cranial cavity.

“In particular, we have studied the morphology of the middle meningeal artery. the venous sinuses and the bridging veins, using the traces these leave in the bone”, explains Bruner.

Intracranial pressure

In the most extreme cases of craneosynostosis (very elongated skulls), the spatial variations in the endocranial cavity cause the meningeal artery to follow them passively and thereby change its route. But the most interesting effect is on the vessels responsible for regulating the drainage of the blood, which present many differences in persons with the condition.

In these individuals, a posterior drainage system, the occipito-marginal system, is often detected, but this is unusual in normal skulls. They also have larger and more frequent bridging veins, which is suspected to be related to the problems of intracranial pressure suffered by people with these anomalies.

“Using the skull traces allows us to investigate these vascular traits in very large samples, such as museum collections, in past populations and fossil species. Therefore, looking at this type of trait is of interest to anthropology, bioarchaeology and medicine”, adds Bruner.

This study was conducted by Stanislava Eisová, a doctoral student on Bruner's team, with the collaboration of the National Museum of Prague (Národní Muzeum).