Cerebrovascular Anatomy – Arterial


o        Internal maxillary – deep face; supplies middle meningeal; ethmoidal branches anastemose with inferolateral cavernous sinus and ophthalmic artery

§         Persistent stapedial artery – provides middle meningeal if no foramen spinosum develops

·         dorsal meningeal (CN VI, part of clivus)

§         (c) Medial (McConnel’s capsular artery) – anterior and inferior pituitary capsule (present in only 28%)

·         aneurysms point superior and can compress optic nerve (arise on superior ICA distal to origin)

·         aneurysms point inferior and medial

·         Aneurysms point posterolateral and can compress CNIII (arise from posterior wall of carotid distal to Pcomm); Pcomm aneurysms are usually superomedial to Pcomm and inferolateral to anterior choroidal

o        Perforators to inferior optic chisam, posterior optic tract, globus pallidus, internal capsule (genu), middle part of cerebral peduncle, substantia nigra, upper red nucleus, subthalamus, and lateral VA and VL thalamus

o        Perforators to lateral half of geniculate body, internal capsule (inferior posterior and retrolenticular), optic radiations, and choroid plexus

·         aneurysms arise superior or superolateral to origin

§         Acomm aneurysms arise from the dominant A1 and point toward the opposite side

§         Anterior inferior frontal – anteromedial frontal lobe

·         Paracentral – central sulcus

·         Inferior parietal

§         Lateral lenticulostriate (usually 2-15) – supply inferomedial substantia innomonata, lateral anterior commissure, putamen, lateral globus pallidus, superior internal capsule, and caudate

·         Anterior parietal – superior parietal lobule

·         Posterior parietal – posterosuperior and inferior parietal lobule, inferior supramarginal gyrus

o        (3) M3 branches are continuations of the above

§         Wallenburg’s syndrome – crossed pain/temperature (ipsilateral face), ipsilateral laryngeal paralysis/ataxia/Horner’s

o        Posterior meningeal (near atlas and falx cerebelli) – also contributions from ECA branches (occipital, ascending pharyngeal)

§         Subarcuate

§         Benedikt – ipsilateral CNIII, red nucleus (tremor), cerebellar peduncle (cerebellar dentothalamic fibers)