Cadaveric findings of a duplicated superior petrosal sinus.

Knowledge of the intracranial dural venous sinuses and their variations is important in the diagnosis and management of many cranial pathologies. We report a unique duplication of the right-sided superior petrosal sinus identified during routine dissection of the skull base.. Lateral to this sinus, a separate and more curvilinear superior petrosal sinus left the normally positioned superior petrosal sinus and traveled posteriorly near the foramen spinosum and then turned medially to drain into the normally positioned superior petrosal sinus. Anteriorly, the two sinuses joined together and drained into the cavernous sinus. Posteriorly, the laterally positioned sinus drained into the normally positioned sinus which then traveled in normal fashion along the petrous ridge to end in the transverse sinus. To our knowledge, such a duplication has not been previously reported in the extant medical literature.