Middle cerebral artery aneurysms are generally divided into proximal aneurysms (from the bifurcation of the internal carotid artery to the bifurcation of the middle cerebral artery), bifurcation aneurysms, and distal aneurysms (on post-bifurcation branches or peripheral branches, M3 to M5). Bifurcations are less common in the distal ones, with the literature reporting around 5%. Large, giant type aneurysms and spindle-shaped aneurysms are more frequent. Due to the importance of blood supply to the middle cerebral artery branches and the unpredictability of their vascular compensatory capacity, rash removal of aneurysms may bring about severe neurological dysfunction, producing limb paralysis and aphasia.