Figure 4. Schematic picture showing the right and left aberrant venous sinuses, in the floor of the posterior cranial fossa. The right aberrant venous sinus (ras) connected the right sigmoid sinus (rss) with the right transverse sinus (rts). The left aberrant venous sinus (las) connected the left sigmoid sinus (lss) with the left transverse sinus (lts). (os: occipital sinus).