COMPARATIVE MICROANATOMY OF THE LATERAL WALL OF THE CAVERNOUS SINUS IN HUMANS AND THE OLIVE BABOON

Despite many studies of the 'cavernous sinus' lateral wall, the anatom y of this area remains controversial. We performed a comparative micro anatomical and histoarchitectural study in 14 humans and in 10 nonhuma n primates (Papio cynocephalus anubis). Venous channels and cranial ne rves were embedded in the 'interperiosteodural space'. The dura propri a of the lateral wall could be removed without entering the venous com partment. The oculomotor and trochlear nerves were accompanied by an a rachnoidal and dural sheath. The oculomotor nerve sheath stopped under the anterior clinoid process in baboons. The trigeminal ganglion was covered posteriorly with an arachnoid membrane and adhered firmly to t he dura propria on lateral and anterior sections. The three branches o f the trigeminal nerve had no arachnoid covering, except for arachnoid granulations in humans. In baboons, the oculomotor and trochlear nerv es were thicker than in humans, while the ophthalmic nerve was thinner . The abducens nerve belonged to the lateral wall of the sinus in babo ons and had no arachnoidal sheath except in the first millimeters of D orello's canal. After leaving their arachnoidal and dural sheath, the intracavernous cranial nerves acquired a typical peripheral sheath. Th e venous channels in both species were true dural sinuses. Willis cord s and adipose tissue were identified.