Blood supply of brain, only arterial anatomy presented at National Institute of Neurosciences as weekly Anatomy session presentation

1. BloodBlood
Supply ofSupply of
brainbrain

3. Two Systems:
• Carotid System ( 80% )
• Vertebrobasilar System (20%)
Polygonal anastomosis at the base of brain-circle of willis

4. Developme
nt

5. Development

6. Development
Foxc1
Required for early stage telencephalic vascular development

7. Blood- Brain Barrier (BBB)

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.

9. •Cervical segment, C1
•Petrous segment, C2
•Lacerum segment, C3
•Cavernous segment, C4,
•Clinoid segment, C5.
•Ophthalmic, or supraclinoid segment, C6
•Communicating, or terminal segment, C7
INTERNAL CAROTID ARTERY (ICA)

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)

18. Anterior cerebral artery:
• 5 Segments A1 – A5

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

21. Anterior cerebral artery: Cortical Distribution

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

28. Posterior communicating artery
:
- It passes backwards to join the
posterior cerebral artery.

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.

30. Middle cerebral artery: Course

32. • Nomenclature
Tree and trunk method
Stem
Lateral Lenticulostriates
Superior and Inferior Division
78% bifurcation pattern
12% Trifurcation
10% no branching
Prefrontal, Precentral, Central, Superior temporal, angular, etc
In relation to anatomical landmarks
M1 (limen insula), M2 (insula), M3 (operculum), M4 (convexity).
Middle cerebral artery:

33. Middle cerebral artery: segments
 M1: Sphenoidal/ Horizontal segment- origin of Lat.
Lenticulostriate perforators
 M2: Insular/ Sylvian segment
 M3: Opercular segment
 M4: Cortical/ Terminal
segment

39. MCA Infarct

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.

43. Vertebral Artery

46. Vertebral Artery : Branches
From
Intradural
Segment
(V4)
 Posterior Inferior
Cerebellar
Arteries (PICA)
lateral medulla, tonsil,
inferior vermis /
cerebellum, choroid
plexus of 4th ventricle
 Anterior Spinal
Arteries
upper cervical spinal
cord, inferior medulla
Posterior Spinal
Arteries
dorsal spinal cord to
conus medullaris
Lower
Extradural
Segments
(V1,V2,V3)
 Cervical muscular,
Meningeal & spinal
branches
 Segmental branches

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)

51. Basilar Artery

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

55. Posterior Cerebral Arteries

56. Posterior Cerebral Arteries

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

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

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

69. Internal Capsule : Blood Supply

70. Intracerebral Haemorrhage (ICH)
• Causes:
• Hypertension, Amyloid angiopathy,
Aneurysm
• AVM, Coagulopathy, Vasculitis.
• Hypertensive patients develop
microscopic aneurysm known as
charcot- bouchard aneurysm which
ruptures.
• sites of bleed:
• Gangliothalamic
Region(hypertensive )
• Other sites lobar area, brain stem &
cerebellum

71. Subarachnoid haemorrhage (SAH)
• Causes:
• Cerebral Aneurysm-70-75 %
• AVM-5%
• Bleeding diathesis,
• Anticoagulants
• Tumors,
• Vasculitis-5%
• Undefined-15%
• Diagnosis:
• CT: blood in basal cistern, sylvian
fissure, interhemispheric fissures.
• LP- Uniformly blood stained or
xanthochromia.

72. Visualization of vascular anatomy
• CT angiogram
• MR Angiogram
• DSA

73. Digital Subtraction Angiography
(DSA)

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

76. Cerebral Aneurysms

77. Arteriovenous malforamation

79. Thank you