The transoccipital parasigmoid canal of the vertebral artery through a vestige of the occipital vertebra.

ABSTRACT:

Purpose

The vertebral artery (VA) typically courses through the foramen magnum to enter the posterior cranial fossa. A transosseous course of the VA through the lateral part of the occipital bone is an unexpected finding. Such an anomaly of the VA is reported here.

Methods

The archived angioCT file of an 81 y.o. female was studied on planar sections and by three-dimensional volume renderings.

Results

The right VA looped above the transverse process of the atlas, and then it descended to enter a canal through the lateral part of the occipital bone. That canal was medial to the posterior condylar canal and the sigmoid sinus. It was termed the parasigmoid canal. The right VA entered the posterior fossa higher than the left VA, immediately posterior to the hypoglossal can

SUBMITTER: Rusu MC 

PROVIDER: S-EPMC11868323 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature