Cerebrovascular Anatomy Arterial
- All named arteries are in italics
- External Carotid Artery 8 branches (SALFOPS)
- Superior thyroid larynx, upper thyroid (rest of thyroid
supplied by branch of thyrocervical trunk)
- Ascending pharyngeal nasopharynx, oropharynx, middle ear, CN
IX/X/XI, meninges; has anastemoses with vertebral artery
- Lingual tongue and floor of mouth
- Facial face, palate, lips; angular branch anastemosis with
orbital branch of ophthalmic
- Occipital posterior scalp, upper cervical musculature,
posterior fossa meninges
- Posterior auricular pinna, external auditory canal, scalp
- Superficial temporal scalp and ear
o
Internal
maxillary deep face; supplies middle meningeal; ethmoidal branches
anastemose with inferolateral cavernous sinus and ophthalmic artery
- Internal Carotid Artery 4 segments
- (1) Cervical no branches; lies posterolateral
to ECA
- (2) Petrosal (intraosseous) in carotid canal
of petrous temporal bone
- Caroticotympanic middle/inner ear; anastemosis with anterior
tympanic branch of maxillary artery
- Vidian (artery of pterygoid canal) foramen lacerum,
vindian canal; anastemosis with external carotid branches
§
Persistent
stapedial artery provides middle meningeal if no foramen spinosum develops
- (3) Intracavernous 3 branches
- (a) Posterior (meningohypophyseal trunk)
- tentorial artery of Bernasconi and Cessinari (tentorium)
- inferior hypophyseal artery (posterior pituitary
capsule)
·
dorsal
meningeal (CN VI, part of clivus)
- (b) Lateral (inferior cavernous sinus
artery) inferior wall of cavernous, foramina ovale/spinosum
§
(c) Medial
(McConnels capsular artery) anterior and inferior pituitary
capsule (present in only 28%)
- (4) Intradural (supraclinoid)
- Ophthalmic sometimes intracavernous or even middle meningeal
(0.5%, blindness with middle meningeal embolization)
- inferior then superolateral to optic nerve, supplies
orbit via central retinal artery and ciliary branches (orbit also
supplied by infraorbital branch of the maxillary artery)
·
aneurysms
point superior and can compress optic nerve (arise on superior ICA distal to origin)
- superior hypophyseal off inferolateral wall of ICA beneath optic nerve; supplies pituitary stalk, tuber cinereum, anterior lobe of the
pituitary, inferior chiasm
·
aneurysms
point inferior and medial
- Pcomm off inferolateral wall of ICA, travels
posterolateral above CNIII to anastemose with PCA
- 50% anomalous (such as fetal PCA where Pcomm caliber
equals PCA, found in 30% bilateral in 8%)
- Perforators to posterior hypothalamus, anterior
thalamus, posterior internal capsule, and subtahalamus
- Anterior thalamoperforators (largest perforators
between mamillary bodies and optic tract)
·
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
- Anterior choroidal off posterior ICA 2-4 mm distal to pcomm,
inferolateral to the optic tract
- Cisternal segment through supracellar cistern,
posteromedially around uncus then posterolaterally through crural and
ambient cisterns to enter choroidal fissure (plexal point)
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
- Plexal segment supplies choroids plexus of anterior
lateral ventricle
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
- Anterior Cerebral Artery 25% are anomalous (azygous),
which have higher risk of aneurysms; 3 segments
- (1) A1 (precommunicating) prior to Acomm
- Medial lenticulostriate (usually about 8) superior
surface of optic nerve and chiasm, anterior hypothalamus, septum
pellicidum, anterior commissure, pillars of fornix, anteroinferior
striatum
- Medial proximal striate (Huebner is medial distal
striate, from A2)
- Acomm in cistern of lamina terminalis, supplies 2
perforators to infundibulum, chiasm, subcallosal area, preoptic
hypothalamus, subcallosal artery and medial artery of corpus
callosum
§
Acomm
aneurysms arise from the dominant A1 and point toward the opposite side
- (2) A2 (proximal pericallosal)
- Medial distal striate (Recurrent Artery of Huebner)
courses back toward proximal A1 and enters anterior perforating
substance to supply head of caudate, anterior internal capsule, anterior
globus pallidus and putamen, septal nuclei, and inferior frontal lobe
- Orbitofrontal gyrus rectus, medial orbibtal gyrus, olfactory bulb
and tract
- Frontopolar medial frontal lobe and lateral surface of superior
frontal gyrus
§
Anterior
inferior frontal anteromedial frontal lobe
- (3) A3 supplies anterior 2/3 of medial cortex
- Callosalmarginal cingulate gyrus, paracentral lobule
- Medial inferior frontal
- Posterior inferior frontal
·
Paracentral central sulcus
- Distal Pericallosal medial parietal cortex,
precuneus
·
Inferior
parietal
- Middle Cerebral Artery sylvian point is the most
posterior branch, lies 5 cm from midline on AP projection
- (1) M1 to M2 bifurcation
- Uncal (often from distal ICA)
- Temperopolar temporal tip
- Anterior temporal
§
Lateral
lenticulostriate (usually 2-15) supply inferomedial substantia innomonata,
lateral anterior commissure, putamen, lateral globus pallidus, superior
internal capsule, and caudate
- (2) M2 to opercular branches leaving Sylvian
fissure; 2 branches
- (a) Superior trunk
- Orbitofrontal middle/inferior frontal gyri, inferior pars
orbitalis
- Prefrontal superior pars orbitalis, pars triangularis,
anterior pars opercularis, part of middle frontal gyrus
- Precentral posterior pars opercularis, middle frontal gyrus,
inferior and medial precentral gyrus
- Central superior postcentral gyrus, upper central sulcus,
anterior inferior parietal lobule
·
Anterior
parietal
superior parietal lobule
- (b) Inferior trunk
- Middle temporal superior temporal gyri, central middle
temporal gyrus, posterior inferior temporal gyrus
- Posterior temporal middle/posterior superior
temporal gyrus, posterior middle and extreme posterior inferior
temporal gyrus
- Temperooccipital posterior half of superior temporal gyrus,
posterior extreme middle temporal gyurs, inferolateral occipital lobe
- Angular posterior aspect superior temporal gyurs, portions
of supramarginal and angular gyri, superior aspect of lateral occipital
lobe
·
Posterior
parietal
posterosuperior and inferior parietal lobule, inferior supramarginal gyrus
o
(3) M3
branches are continuations of the above
- Vertebral from subclavian artery (5% from aorta on left);
enters foramen transversarium at C6, exits laterally at C2, travels
posteriorly along atlas and enters foramen magnum; 50% left dominant, 25%
right dominant, 40% have one hypoplastic; anastemoses with ECA and
branches of thyrocervical and costocervical trunks
- Perforators supply pyramids, inferior olive, vagal and hypoglossal
nuclei, and reticular formation
- Posterior spinal gracilis and cuneatis, inferior cerebellar
peduncle
- Anterior spinal pyramid, medial lemniscus, medial
longitudinal fasciculus, inferior olive, vagal/hypoglossal nuclei
- PICA (occasionally arises extracranially, 25% of vertebral
arteries end in PICA) 4 segments (Anterior medullary, Lateral medullary
(CNIX/X/XI), Tonsillomedullary, Telovelotonsilar); supplies choroids
plexus of 4th ventricle, posterior lateral medulla, tonsils,
vermis, posterior inferior hemispheres
§
Wallenburgs
syndrome
crossed pain/temperature (ipsilateral face), ipsilateral laryngeal
paralysis/ataxia/Horners
o
Posterior
meningeal (near atlas and falx cerebelli) also contributions from ECA
branches (occipital, ascending pharyngeal)
- Basilar
- AICA crosses CNVI and CPA cistern to internal acoustic
canal, anterior/inferior to CN VII/VIII; supplies CNVII/VIII,
inferolateral pons, middle cerebellar peduncle, flocculus, anterolateral
cerebellar hemispheres
- Internal auditory
- Recurrent perforating arteries
§
Subarcuate
- Labarinthine
- Paramedian branches ventral pons and midbrain
- Long and short circumferential arteries ventral pons, anastemose
with AICA at middle cerebellar peduncle
- SCA below CN III/IV to superior vermis and hemispheres
of cerebellum, deep white matter, deep nuclei
- Weber ipsilateral CNIII, pyramid (contralateral body
motor deficit)
§
Benedikt
ipsilateral CNIII, red nucleus (tremor), cerebellar peduncle (cerebellar
dentothalamic fibers)
- Posterior Cerebral Artery supplies inferior temporal
gyrus, most of occipital lobe, superior parietal lobule, brainstem, and
choroid of 3rd/lateral ventricles
- (1) P1 peduncular cistern to Pcomm
- Posterior thalamoperforators to thalamus and midbrain
- Medial posterior choroidal artery anteromedial along rostral
3rd ventricle to supply midbrain tectum, posterior thalamus,
pineal, and choroid plexus of 3rd ventricle (not lateral)
- (2) P2 in ambient cistern from Pcomm to
quadrigeminal plate, around midbrain above CNIV and tentorial incisura
- Lateral posterior choroidal thalamus, choroid plexus of
lateral ventricles (anastemosis with anterior choroidal)
- Medial and lateral thalamogeniculate medial and lateral
geniculate bodies, pulvinar, superior colliculus, crus cerebri, pineal
- (3) P3 starts posterior to midbrain
- Posterior temporal posterior temporal lobes,
occipital/temporal/lingual gyri
- Anterior temporal branches inferior temporal lobes,
anastemose with MCA branches
- Internal occipital
- Patietooccipital posterior 1/3 of cerebral hemispheres,
anastemoses with ACA
- Calcarine occipital pole anastemoses with MCA
- Posterior pericallosal supplies splenium of
corpus callosum, anastemses with ACA
- Summary of perforators
- Anteromedial
- From: ACA, Acomm
- To: anterior perforating substance to anterior
pituitary, supraoptic, preoptic nuclei
- Anterolateral
- From: MCA, ACA (Huebner)
- To: striatum, internal capsule
- Posteromedial
- From: PCA, Pcomm
- To: pituitary, infundubulum, tuberal hypothalamus;
thalamoperforators also supply mamillary bodies, subthalamus, and
midbrain
- Posterolateral
- From: PCA (thalamogeniculate)
- To: caudal thalamus
- Supply to Internal Capsule
- Lateral/rostral anterior supplied by
lenticulostriate (MCA)
- Genu supplied by ICA perforators
- Caudal posterior and retrolenticular supplied by
anterior chroidal
- Rostral posterior supplied by Huebner
- Caudal posterior supplied by Pcomm
- EC-IC Anastemoses
- Ascending pharyngeal to vertebral artery (C3) and
petrous/cavernous branches of ICA
- Facial (angular) to ophthalmic (orbital)
- Occipital to vertebral (C1C2)
- Posterior auricular to ICA (stylomastoid)
- Maxillary to ICA:
- Middle meningeal to ophthalmic (ethmoidal)
- Artery of foramen rotundum/accessory meningeal to
inferolateral trunk of ICA
- Vidian artery to infratemporal ICA
- Anterior and deep temporal arteries to ophthalmic
(lacrimal, palpebral, muscular)
- Persistant fetal carotid-vertebral anastemoses (higher risk of aneurysm)
- Primitive trigeminal most common (besides fetal
PCA), 0.1-0.5%
- From: ICA (usually proximal to cavernous sinus) or meiningohypophyseal
trunk
- To: basilar artery between SCA and AICA
- Persistent otic/acoustic through internal acoustic
meatus
- From: petrous ICA
- To: basilar
- Persistent hypoglossal 2nd most frequent,
0.1%; through hypoglossal canal
- From: cervical ICA
- To: basilar
- Proatlantal intersegmental artery
- From: ECA or cervical ICA
- To: vertebral artery between C1 and occiput
- Blood Supply to Dura
- Anterior meningeal artery from ophthalmic
- Middle meningeal artery from maxillary branch of external
carotid
- Posterior meningeal from occipital and vertebral arteries