[The accessory middle cerebral artery (author's transl)]

Abstract

The accessory middle cerebral artery has rarely been documented. Four cases of the anomalous artery were found in 1240 carotid angiograms, the incidence being estimated to be 0.24 to 0.34%. Ages of the patients were 45, 52, 53, and 56. They were two males and two females. In two patients, the angiography was carried out because of positive neurological signs after head injury, and in the other two, because of cerebrovascular stroke. All the anomalous arteries were found as incidental findings. The angiography was carried out bilaterally in two patients and the anomalous arteries were found only on one side. They arose from the horizontal portion of the anterior cerebral artery and coursed laterally in paralled with the stem of the middle cerebral artery. Two of them gave rise to the perforating arteries into the brain which accompanied those from the middle cerebral artery. These atomalous arteries were identified very easily on an antero-posterior projection of the angiogram. In the most striking patient, the 52-year-old man, a selective angiography for the middle cerebral artery, which did not demonstrate the anterior cerebral artery and its branch, the accessory middle cerebral artery, was carried out and in the light of the findings, the accessory middle cerebral artery could be identified running in elliptic circle just above D1 on the lateral projection of the routine carotid angiogram. All the accessory middle cerebral arteries in our series were not associated with either intracranial aneurysm or anomalies such as agenesis of the corpus callosum and reduplication of the circle of Willis.