8. INTERNAL CAROTID ARTERY (ICA)
Begins – bifurcation of Common Carotid A
Enters middle cranial fossa through the carotid canal at
the base of skull
Lies beside dorsum sellae
In the cavernous sinus: Lies Horizontal
Emerge out – medial side of Ant. Clinoid Process-
perforates dura & arachnoid mater- enters subarachnoid
space
Turns posteriorly- below optic nerve
Turns upwards- lateral to optic chiasma
Now is under anterior perforated substance
Divides- into ANTERIOR & MIDDLE Cerebral
Arteries.
13. •C1: Branches from the cervical portion - none.
•C2: Branches from the petrous portion
• Caroticotympanic arteries
• Artery of pterygoid canal (vidian artery)
•C3: Branches from the lacerum portion - none
•C4: Branches from the cavernous portion
• Branches of the meningohypophyseal trunk:
• Meningeal branch - to the meninges of the anterior cranial fossa
• Clivus branches - tiny branches that supply the clivus
• Inferior hypophyseal artery
• Capsular branches wall of cavernous sinus
• Inferolateral trunk: Branches to trigeminal ganglion - to trigeminal ganglion
•C5: Branches from the clinoid portion - none
•C6: Branches from the ophthalmic portion
• Ophthalmic artery
• Superior hypophyseal artery
•C7: Branches from the communicating portion
• Posterior communicating artery
• Anterior choroidal artery
• Anterior cerebral artery (a terminal branch)
• Middle cerebral artery (a terminal branch)
14. Hypophyseal arteries
•They arise from the intracavernous section of the
internal carotid to supply the neurohypophysis.
Ophthalmic artery:
•It passes into the orbit through the optic foramen.
•It supplies the structures of the orbit, frontal and
ethmoidal sinuses, frontal part of the scalp and dorsum
of the nose.
15. Anterior choroidal artery:
•It supplies the optic tract, choroid plexus
of the lateral ventricle, hippocampus and
some of the deep structures of the
hemisphere, including the internal capsule
and globus pallidus.
•The territory supplied by it includes the
motor and sensory cortices for the lower
limb.
16. Anterior cerebral artery:
• Passes medially above the optic nerve
and then passes into the median
longitudinal fissure between the frontal
lobes where it joins the corresponding
vessels of the opposite side by anterior
communicating artery.
• Supplies oxygenated blood to most
midline portions of the frontal lobes and
superior medial parietal lobes.
• Part of the Circle of willis
• Right and Left connected by Anterior
Communicating Artery (AcomA)
19. Segments….
• AI; ACA from origin to ACoA
• A2; from ACoA to branch-
point of callosomarginal
• A3; from branch-point of
callosomarginal to
superiorsurface of cc
• A4: pericallosal
• A5: terminal branch
26. Anterior cerebral artery stroke
Stroke occurs Only If a blockage occurs in the A2 segment or later
27. Anterior cerebral artery stroke
Paralysis or weakness of the foot and leg on the
opposite side, due to involvement of leg part of the
motor cortex
Cortical sensory loss in the opposite foot and leg
Gait apraxia (impairment of gait and stance)
Abulia, akinetic mutism, slowness and lack of
spontaneity
Urinary incontinence which usually occurs with
bilateral damage in the acute phase
Frontal cortical release reflexes: Contralateral
graspreflex, sucking reflex, paratonic rigidity
29. Middle cerebral artery:
It is the largest branch of the 3 cerebral arteries and its
cortical territory is the largest. It passes laterally to enter
the lateral fissure within which it subdivides.
Its branches supply the whole of the lateral surface of the
frontal, parietal and temporal lobes except those areas
which are supplied by the anterior cerebral artery.
It supplies the primary motor and sensory cortices for the
whole body excluding the lower limb. The auditory
cortex and the insula in the depth of the lateral fissure.
42. Vertebral Artery
Branch of first part of subclavian A
Passes- foramen transversarium C6- C1
Enters through foramen magnum – perforates dura &
arachnoid mater – enters subarachnoid space
Turns upwards, forwards, medially – medulla
oblongata
Lower border of pons – joins opposite side to form
Basilar A.
47. Lateral medullary syndrome of
Wallenberg
Occlusion of the posterior inferior
cerebellar artery (PICA) or one of its
branches or of the vertebral artery
Vomiting, vertigo, nystagmus
Ipsilateral Cerebellar signs
Ipsilateral facial hemisensory loss
Contralateral hemisensory loss
Ipsilateral lower cranial nerve palsy
Ipsilateral Horner’s Syndrome
48. Medial medullary syndrome of
Dejerine
Occlusion of the paramedian branches of
Anterior spinal Arteries or vertebral
artery
Ipsilateral Hypoglossal nerve palsy
Contralateral hemiplegia
Contralateral loss of discriminative
touch
49. Subclavian steal syndrome (SSS)
Caused by proximal narrowing of
Subclavian Artery.
Blood flows retrogradely away from heart
from Vertebral arteries to supply the limbs.
Cause TIA, Syncope and Neurologic deficit
due to circulatory insufficiency in posterior
circulation.
More severe in times of exercise or
strenuous limb activity.
Causes: Atherosclerosis, Cervical rib,
Takayasu’s arteritis
50. Basilar Artery
Formed by the union of the two vertebral arteries at
the lower border of Pons
Ascends on the front of the pons lodged in the
Basilar groove
Ends at the upper border of the pons by dividing into
2 Posterior cerebral arteries (PCA)
53. Basilar Artery : Branches
Group
Paramedian
Perforating/ Short
circumferential
Paired long
circumferential
branches
Pontine branches
Labyrinthine
arteries
Anterior inferior
Cerebellar arteries
(AICA)
Superior Cerebellar
Arteries (SCA)
Posterior Cerebral
arteries (PCA)
54. Due to hemorrhage or infarction of pons due to occlusion
of proximal & middle segment.
Quadriplegia with preserved consciousness & preserved
vertical eye movement.
suggest complete pontine & lower mid brain infarct.
Total locked-in syndrome, or completely locked-in state
(CLIS), is a version of locked-in syndrome wherein the
eyes are paralyzed as well
Locked in syndrome
57. Posterior Cerebral Arteries:
Segments
P1: Basilar bifurcation to Posterior Communicating A
P2: Portion in the peri-mesencephalic cistern
P3: Portion in the Calcarine fissure
58.
59.
60.
61.
62.
63.
64. Posterior cerebral artery stroke
Contralateral loss of pain and temperature
sensations.
Visual field defects (contralateral hemianopia
with macular sparing).
Prosopagnosia with bilateral obstruction of the
lingual and fusiform gyri.
Superior Alternating Syndrome (Weber's
syndrome)
Ipsilateral deficits of oculomotor nerve,
Contralateral deficits of facial nerve (only lower
face, upper face receives bilateral input), vagus nerve
and hypoglossal nerve
Horner's Syndrome
65.
66. Artery of Percheron (AOP)
Rare anatomic variation in which a single arterial
trunk arises from the posterior cerebral artery
(PCA) to supply both sides of brain structures; the
thalamus and midbrain.
Occlusion by a clot, could result in an infarct
impairing structures on both sides of the brain. This
can produce a bizarre disturbance such as sleep from
which the patient cannot be awakened.
67. Circle of Willis
• Lies in the interpeduncular fossa at the
base of the brain
• Formed by anastomosis between two
ICA and two vertebral arteries
• The A.com artery, ACA, PCA, P.com
artery and Basilar artery contribute
• Allows blood to be distributed to any
part of both cerebral hemispheres.
68. Formed by:
Anterior Cerebral A
Anterior Communicating A
Internal Carotid A
Posterior Communicating A
Posterior Cerebral A
Perforating Branches
Antero-median group
Antero- lateral group
Postero-median group
Postero lateral group
74. Visualization of vascular anatomy
• Intraoperative visualization
• ICG: Indocyanine green
• Fluorescent microscopy
• Real time augmented reality images
75. • An aneurysm is an abnormal, balloon-like, swelling of an
artery. Rupture of this artery may cause subarachnoid
haemorrhage or intracerebral haemorrhage. A sudden
severe headache and neck stiffness are followed by coma and
neurological deficits.
• An angioma or arteriovenous malformation (AVM) is a
congenital collection of swollen, blood vessels that can rupture
causing cerebral haemorrhage or steal blood from adjacent
brain regions leading to epilepsy and a focal cerebral syndrome.
Pathologies
BLOOD BRAIN BARRIER Exists at capillary level, from inside to outside consists of: • endothelial cells of capillaries with tight junctions • Basement membrane of endothelial cells • Perivascular extensions of astrocytes • Intercellular space filled with tissue fluid • Neuronal cell membrane
it first ascends a short distance, then curves anteriorly and medially. The artery lies at first in front of the cochlea and tympanic cavity; from the latter cavity it is separated by a thin, bony lamella, which is cribriform in the young subject, and often partly absorbed in old age. Farther forward it is separated from the trigeminal ganglion by a thin plate of bone, which forms the floor of the fossa for the ganglion and the roof of the horizontal portion of the canal.. The artery is separated from the bony wall of the carotid canal by a prolongation of dura mater, and is surrounded by a number of small veins and by filaments of the carotid plexus, derived from the ascending branch of the superior cervical ganglion of the sympathetic trunk.
it first ascends a short distance, then curves anteriorly and medially. The artery lies at first in front of the cochlea and tympanic cavity; from the latter cavity it is separated by a thin, bony lamella, which is cribriform in the young subject, and often partly absorbed in old age. Farther forward it is separated from the trigeminal ganglion by a thin plate of bone, which forms the floor of the fossa for the ganglion and the roof of the horizontal portion of the canal.. The artery is separated from the bony wall of the carotid canal by a prolongation of dura mater, and is surrounded by a number of small veins and by filaments of the carotid plexus, derived from the ascending branch of the superior cervical ganglion of the sympathetic trunk.
Petrous short segment that begins above the foramen lacerum and ends at the petrolingual ligament, a reflection of periosteum between the lingula and petrous apex (or petrosal process) of the sphenoid bone
The cavernous segment, or C4, of the internal carotid artery begins at the petrolingual ligament and extends to the proximal dural ring. formed by the medial and inferior periosteum of the anterior clinoid process. first ascends toward the posterior clinoid process, then passes forward by the side of the body of the sphenoid bone, and again curves upward on the medial side of the anterior clinoid process, and perforates the dura mater forming the roof of the sinus. The curve in the cavernous segment is called the carotid siphon. This portion of the artery is surrounded by filaments of the sympathetic trunk and on its lateral side is the abducent nerve, or cranial nerve VI.
The cavernous segment, or C4, of the internal carotid artery begins at the petrolingual ligament and extends to the proximal dural ring. formed by the medial and inferior periosteum of the anterior clinoid process. first ascends toward the posterior clinoid process, then passes forward by the side of the body of the sphenoid bone, and again curves upward on the medial side of the anterior clinoid process, and perforates the dura mater forming the roof of the sinus. The curve in the cavernous segment is called the carotid siphon. This portion of the artery is surrounded by filaments of the sympathetic trunk and on its lateral side is the abducent nerve, or cranial nerve VI.
Passes medially above the optic nerve and then passes into the median longitudinal fissure between the frontal lobes where it joins the corresponding vessels of the opposite side by anterior communicating artery.
Supplies oxygenated blood to most midline portions of the frontal lobes and superior medial parietal lobes.
Part of the Circle of willis
Right and Left connected by Anterior Communicating Artery (Acom)
Passes medially above the optic nerve and then passes into the median longitudinal fissure between the frontal lobes where it joins the corresponding vessels of the opposite side by anterior communicating artery.
Supplies oxygenated blood to most midline portions of the frontal lobes and superior medial parietal lobes.
Part of the Circle of willis
Right and Left connected by Anterior Communicating Artery (Acom)
The cortical branches. -Two or three orbital branches supply the
olfactory cortex,
gyrus rectus and
medial orbital gyrus. –
Frontal branches supply the
corpus callosum,
cingulate gyrus,
medial frontal gyrus and
paracentral lobule. –
Parietal branches supply the
precuneus -
the frontal and parietal supply a strip of territory on the superolateral surface that represent the lower limb.
CENTRAL BRANCHES: -they supply
the rostrum of the corpus callosum,
the septum pellucidum,
anterior part of the putamen,
the head of the caudate nucleus and
adjacent parts of the internal capsule
CENTRAL BRANCHES: -they supply
the rostrum of the corpus callosum,
the septum pellucidum,
anterior part of the putamen,
the head of the caudate nucleus and
adjacent parts of the internal capsule
Cortical branches
Frontal branches supply the
precentral, middle and inferior frontal gyri.
Two parietal branches are distributed to the
postcentral gyrus, the
lower part of the superior parietal lobule and
the whole inferior parietal lobule.
Two or three temporal branches supply the
lateral surface of the temporal lobe. -motor and somatosensory cortices, with the exception of the lower limb, the auditory area and the insula.
Two or three temporal branches supply the
lateral surface of the temporal lobe.
the lateral striate or lenticulostriate arteries - the lentiform complex and the internal capsule and the caudate nucleus
-motor and somatosensory cortices, with the exception of the lower limb, the auditory area and the insula. the lateral striate or lenticulostriate arteries - the lentiform complex and the internal capsule and the caudate nucleus
the lateral striate or lenticulostriate arteries - the lentiform complex and the internal capsule and the caudate nucleus
Medulla blood supply
• Two vertebral arteries.
• Anterior and posterior spinal arteries.
• Anterior and posterior inferior cerebellar arteries.
• Basilar artery
Mid brain blood supply
• Most of the blood supply is derived from branches of the basilar artery.
• Posterior cerebral
• Superior cerebellar
• Posterior communicating
• posterior choroidal
Pons blood supply
• Numerous (pontine) branches from the basilar artery.
• Superior cerebellar artery.
Medulla blood supply
• Two vertebral arteries.
• Anterior and posterior spinal arteries.
• Anterior and posterior inferior cerebellar arteries.
• Basilar artery
• P1 or Peduncular segment • short segment from the basilar tip to the PComA –
Mesencephalic br. – Cr. Nv. Nuclei 3 - 6 –
Thalamoperforating arteries - diencephalon and midbrain
•P2 or ambient segment • runs in the ambient cistern from the PComA to the portion of paramesencephalic cistern –
Thalamogeniculate br. –
Medial posterior choroidal arteries –
Lateral posterior choroidal arteries –
Ant temporal
cortical branches.
Temporal branches-to the uncus and the parahippocampal, medial and lateral occipitotemporal gyri.
Occipital branches- the cuneus, lingual gyrus and posterolateral surface of the occipital lobe.
Parieto-occipital branches -cuneus and precuneus. -the visual areas of the cerebral cortex and other structures in the visual pathway.
The central branches the anterior thalamus, subthalamus, globus pallidus and lateral geniculate body .
the choroid plexus of the third and lateral ventricles and the fornix.
supply the peduncle and the posterior thalamus, superior and inferior colliculi, pineal gland and medial geniculate body.
Striate branches of anterior cerebral artery. (recurrent artery of Huebner). - genu and anterior limb
• Medial and lateral striate branches of the middle cerebral artery. (Charcot‘s artery of cerebral haemorrhage). -the posterior limb of the internal capsule.
• Central branches of the anterior choroidal artery -sublentiform part.
• Some direct branches from the internal carotid artery -genu.
• Central branches of the posterior communicating artery.
• Posterolateral central branches of the posterior cerebral artery -retrolentiform and sublentiform parts