Relationship between cisternal segment of oculomotor nerve and its surrounding vessels

Objective: To study the neurovascul ar relationship between cisternal segment of the oculomotor nerve and its surrounding vessels. Methods:Samples of human brain were obtained with arteries system perfused with red latex and fixed in 10% formaldehyde solution. After removal of the hemisphere, the oculomotor nerve was microdissected under the stereoscopic microscope together with the arteries at the base of the brain. Results:The primary vessels in contact with the oculomotor nerve were the superior cerebellar artery (100%) and the posterolateral pontine artery (42.9%) in the ventral surface of the cisternal segment. The dorsal surface of cisternal segment of nerve had close relationship with posterior cerebral artery (100%), the posterior communicating artery (14.8%), the quadrigeminal artery (100%), the accessory quadrigeminal artery (10.7%) and the medial posterior choroidal artery (10.7%). The nutrient arteries of oculomotor nerve mainly originate from the branches of the medial posterior group of the arterial circle in the base of brain. Vascular penetration was noted in 14.3% of the oculomotor nerve, the most common penetrating vessel was the quadrigeminal artery and accessory quadrigeminal artery. Conclusion:The neurovascular relationship in the cisternal segment of the oculomotor nerve is complicated. The vascular compression and the arterial aneurysma of the cisteral segment of the oculomotor nerve may result in clinical ophthalmoplegia and associated nerve symptoms.