Abstract
Three accessory middle cerebral arteries are described in two out of 75 brains dissected under the operating microscope. Each artery originated from the anterior cerebral artery, lateral to its junction with the anterior communicating artery, followed the proximal segment (A1, pars precommunicalis) of the anterior cerebral artery, then the horizontal portion (M1, pars sphenoidalis) of the middle cerebral artery towards the lateral sulcus. Each supplied the lateral orbital gyrus, the gyrus longus of the insula, part of the putamen, the head of the caudate nucleus and the anterior limb of the internal capsule. The presence of the accessory middle cerebral artery is discussed with regard to the recurrent artery of Heubner (A. recurrens, A. centralis longa).