Modalities of origin of the middle cerebral artery. Incidence on the arrangement of the perforating branches.

In a series of 100 anatomical dissections on the basal brain arteries a case of real duplication at the middle cerebral artery level has been found. The importance of such a finding is discussed in the light of literature data. The knowledge of similar anatomical patterns is fundamental in the study of the lenticulostriate arteries arising from the sphenoidal segment of the middle cerebral artery. In fact the neurosurgeon must be familiar with all the possible variations of these perforators, given that the opening of the Sylvian fissure is by now an obligatory manoeuvre for the transcisternal access to the circle of Willis.