A rare marginal tentorial artery to ophthalmic artery anastomosis.

We report a patient with a marginal tentorial artery to ophthalmic artery anastomosis. A middle-aged man presented with subarachnoid hemorrhage and underwent angiography, where selective microcatheter injection of the meningohypophyseal trunk and marginal tentorial artery revealed a collateral to the distal ophthalmic artery. The radiological findings, embryology behind ophthalmic artery anastomoses and the neurosurgical and neurovascular relevance are discussed.