"They are shorter, thinner and fewer in number than the lateral lenticulostriate arteries, which arise more distally along the M1 segment."
"Some controversy persists regarding their origin; most describe them as arising from the A1 segment of the ACA 1,3. However, some, including Osborn 2, divide the perforating arteries that arise from the middle cerebral artery (MCA) M1 segment into medial (those arising proximally) and lateral (those arising more distally) groups. Furthermore, these perforating arteries can arise from other proximal branches (e.g. the fronto-orbital artery) 4. It is therefore easier to consider these arteries from the point of view of the tissue they supply, rather than from which artery they arise."
"Some controversy persists regarding their origin; most describe them as arising from the A1 segment of the ACA 1,3. However, some, including Osborn 2, divide the perforating arteries that arise from the middle cerebral artery (MCA) M1 segment into medial (those arising proximally) and lateral (those arising more distally) groups. Furthermore, these perforating arteries can arise from other proximal branches (e.g. the fronto-orbital artery) 4. It is therefore easier to consider these arteries from the point of view of the tissue they supply, rather than from which artery they arise."