Groove for inferior petrosal sinus

The groove for inferior petrosal sinus is a depression in the posterior cranial fossa of the cranial cavity that accommodates the inferior petrosal sinus. This groove can be found at the junction of the petrous part of the temporal bone and the basilar part of the occipital bone, known as the petrooccipital fissure. This fissure, along with the adjacent regions of the petrous temporal bone and the basilar occipital bone, collectively form the bony sulcus or groove for inferior petrosal sinus. The groove extends laterally into the jugular foramen.

It's important to note that the inferior petrosal sinus is a paired intracranial venous channel that typically emerges from the posterior part of the cavernous sinus on each side. It runs inside this groove and ends up draining into the junction of the sigmoid sinus and internal jugular vein within the jugular foramen on the respective side.

Various structural variations of the groove for inferior petrosal sinus have been documented in scientific literature. For example, it may be absent altogether or may exist in a complete or incomplete form. Additionally, the groove has been reported to exist as either a partial or complete bony tunnel through which the inferior petrosal sinus passes.