Blood supply of brain

1. BY: DR. ANKIT KUMAR GARG
GUIDE: DR. S.L. MATHUR SIR
BLOOD SUPPLY OF BRAIN AND SPINAL
CORD AND DISEASE OF SPINAL CORD

2. CONTENT
 BLOOD SUPPLY OF BRAIN
 CIRCLE OF WILLIS
 CAROTID SYSTEM
 ACA & MCA SUPPLY & STROKE
 VERTEBRAL SYSTEM
 BRAIN STEM STROKES
BLOOD SUPPLY OF SPINAL CORD
DISEASE OF SPINAL CORD

3. INTRODUCTION
 The continuous blood supply to brain is utmost important because of its high metabolic
demands of oxygen and glucose
 Highly sensitive to hypoxia and hypoglycemia
 Consciousness is lost within 10 seconds of cessation of blood flow, irreversible damage starts
to occur at about 4 minutes and is completed within 10 mins
 Although brain constitute 2%(1/50th) of total body weight , it receives 20%(1/5th) of total
cardiac output.
 Adequate Normal cerebral blood flow 50-55ml/100gm/min.
Electrical failure occurs when blood flow <18ml/100gm/min
cell damage <10ml/100gm/min.

4. Blood supply of brain

Carotid system vertebral
system
(internal carotid artery) (vertebrobasilar
system)
80% 20%

5.  Internal Carotid Artery : branch of Common
Carotid artery
 Right Common Carotid arises from brachio-cephalic
trunk(right subclavian & right common carotid)
 Left arises directly from arch of aorta
 Vertebral Artery : branch of postero-superior portion
of Subclavian artery

8. CIRCLE OF WILLIS

9. CIRCLE OF WILLIS
SITE: at the base of the brain
FUNCTION: important anastomoses between two
internal carotid arteries in front and vertebro-
basilar system behind. The importance of this
wide anatomoses is to maintain the blood
circulation in brain even if any one or 2
component is compromised.
ARTERIES forming it:
 Right and left internal carotid arteries
 Rt. and lt. ACA.
 Rt. and lt. PCA.
 Posterior communicating arteries .

11. BRANCHES OF ICA
 MEMONICS TO REMEMBER- OPAAM
O- Opthalmic artery(1st branch)
p- posterior communicating artery
A-Anterior choriodal artery (post. Choriodal is a
branch of PCA)
A- Anterior cerebral artery
M- Middle cerebral artery

12. BRANCHES OF ACA
Medial striate artery(recurrent artery of Heubner)
(supplies the lower part of the anterior limb and genu of the internal
capsule)
Orbitofrontal branches
Frontopolar artery
Callosomarginal artery
Pericallosal artery

13. CORTICAL BRANCHES OF
ACA

14. CORTICAL STROKE: Anterior cerebral
artery stroke
• 3 important structures supplied by anterior
cerebral artery (ACA) are:
a) Prefrontal cortex(executive functions)-
responsible for personality, complex behaviour
and decision making.
b) Supplementary motor area- changing
between motor behaviours, micturating
inhibitory area.
c) Paracentral lobule- have sensory and motor
fibres of contralateral lower limb.

15. ACA BLOCKAGE
Capsular branch occlusion(Heubner artery):
Facio-brachial monoplegia
Frontal branches occlusion
1.Severe behavior disturbance (apathy or abulia,akinetic)
2. Perseveration
3.Grasp reflexes, and diffuse rigidity –gegenhelton

17. MIDDLE CEREBRAL ARTERY
(MCA)
 Passes through the sylvian fissure to appear
superficially on lateral part of the brain giving various
branches.
 In the sylvian fissure, it gives off lenticulostrial branches
which supplies much of the basal ganglia and upper
part of internal capsule.
 When superficial, its gives off a superior superficial
branch(which runs superficially on lateral surface) and
an inferior superficial branch which runs deep in the
sylvian fissure.
 Superior branch supplies motor and the sensory
strips/ areas.
 In the dominant hemisphere(commonly left
hemisphere), it supplies the Brocas and the

19. 1. Superior division(frontoparietal area)
A) Prefrontal
B) Precentral (prerolandic)
C) Central (rolandic)
2. Inferior division(temporoparietal area)
A) Middle temporal
B) Posterior temporal
C) Angular
D) Parietal

20. Middle cerebral artery

21. MCA STEM BLOCKAGE
 Contralateral hemiplegia, hemianesthesia
 Homonymous hemianopia with macula sparing
 Gaze preference towards side of lesion (in cerebral hemisphere)
 Dysarthria (due to facial weakness)
 Global aphasia---dominant hemisphere involvement
 Constructional apraxia, neglect, anosogonosia---non dominant
hemisphere involvement

22. MCA: STROKE
ARTERY
AFFECTED
AREA
INVOLVED
SYMPTOM
LENTICULOSTRIAL
ARTERY
INTERNAL CAPSULE CONTRALATERAL
MOTOR WEAKNESS +/-
SESNSORY
INVOLVEMENT+/-
HOMONYMOUS
HEMIANOPIA
SUPERFICIAL ARTERY LATERAL SURFACE OF
SAME HEMISPHERE –
precentral /postcentral area
WEAKNESS (MOTOR+/-
SENSORY)OF
CONTRALTERAL FACE
AND UPPER LIMB
*sparing lower limb as it is
supplied by ACA
a) if DOMINANT
LOBE
(Broca’s &
Aphasia
(MOTOR/SENSORY/GLO
BAL)

23. POSTERIOR CEREBRAL
ARTERY(PCA)
• Early in its course it gives deep branches to thalamus and a part of midbrain.
• Superficial branches to – 1) Occipital lobe
2) Inferior aspect of temporal lobe and part of parietal lobe.
3)Splenium of corpus callosum (carries fibres between two occipital lobes).
• Structural variation is quite common in PCA.
• In occipital lobe, we have our primary and associated visual area, important
in perception and interpretation of visual information supplied by PCA.

24. PCA course and its branches

25. P1 Syndrome
 Midbrain, sub-thalamic and thalamic sign due to occlusion of P1
segment PCA or its penetrating branches.
 Infarction usually occurs in the ipsilateral sub-thalamus and medial
thalamus and in the ipsilateral cerebral peduncle and mid brain.
 Claude’s syndrome: 3rd nerve palsy with contralateral ataxia
 Weber syndrome: 3rd nerve palsy with contralateral hemiplegia
 Thalami Dejerine Roussy syndrome: it is thalamic stroke.
Bcoz involvement of spinothalamic tract, contralateral hemisensory
loss followed by agonizing,searing or burning pain in affected areas

26. P2 SYNDROME
 Occlusion of the distal PCA causes infarction of the
medial temporal and occipital lobes.
 Contralateral homonymous hemianopia without macular
sparing
 Memory disturbance due to hippocampal involvement.
 Alexia without agraphia due to involvement of splenium
of corpus callosum.

27. INTERNAL CAPSULE : blood
supply

28. STROKE – Internal Capsule
Can present as :
A) Pure motor stroke caused by infarct in internal
capsule is the most common form of lacunar
stroke syndrome.
B) Mixed sensorimotor weakness is also seen
when posterior limb of internal capsule is
affected.
C) Upper motor neuron signs seen with internal
capsule stroke are hyperreflexia, spasticity,
babinski positive, clonus.

29. LACUNAR STROKE SYNDROME: 5
classic syndrome
1) Pure motor stroke- most common syndrome, usually
occurs with infarction of posterior limb of internal
capsule or basilar surface of pons. Affect face arm or
leg with equal proportion.
2) Ataxic hemiparesis - 2nd most common. Seen with
lacunar infarct of internal capsule, corona radiata,or
basilar surface of pons. It is characterised by
combination of cerebellar and motor signs. Affects
foot/ leg more than hand/arm.
3) Pure sensory deficit – seen with infarction of VPL
nucleus of thalamus
4) Dysarthria-clumsy hand syndrome- seen with
infarction of Genu or basilar surface of pons.
5) Mixed sensorimotor – seen with infarction thalamus

30. WATERSHED AREAS &ITS
STROKE
• Defined as an ischemic or blood flow blockage that
is localised to the border zone between the territorial
of 2 major or arteries in brain.
• 10 % of all ischemic strokes area watershed strokes.
• 2 primary region in brain are cortical/external and
internal/subcortical. Cortical (external )watershed are
localised between the watershed territories of
ACA/MCA/PCA. Internal watershed are in the white
matter along and slightly along the lateral ventricle
between superficial and deep arterial system of MCA
or between superficial system of MCA & ACA.

31. WATERSHED AREAS

33. Branches of 4th part of Vertebral Artery
 Anterior spinal artery
 Posterior spinal A
 Posterior inferior cerebellar artery (PICA)
 Medullary artery
 Meningeal artery

34. Branches of Basilar Artery
 Anterior inferior cerebellar A
 Superior cerebellar A
 PCA
 Pontine artery
 Labyrinthine artery

35. BLOOD SUPPLY OF
MIDBRAIN
 Posterior cerebral artery (PCA)
 Superior cerebellar artery
 Posterior communicating artery
 Anterior choroidal artery

36. BLOOD SUPPLY OF PONS
 Basilar artery(paramedian area)
 Superior cerebellar artery
 Pontine branches(upper lat.
Area)
 Anterior inferior cerebellar
artery(lower lat. Area)

37. BLOOD SUPPLY OF MEDULLA
 Vertebral artery
 PICA
 Anterior spinal artery
 Posterior spinal artery

38. BLOOD SUPPLY OF
CEREBELLUM
 Superior cerebellar A(sup.
/upper part)
 Anterior inferior cerebellar
artery (lateral part)
 Posterior inferior cerebellar
Artery(lower part)

39. BRAIN STEM STROKE SYNDROMES

40. PONTINE SYNDRMES

41. LATERAL MEDULLARY (WALLENBERG)
SYNDROME
 Occlusion of any of five vessel may be responsible- vertebral, PICA,
superior, middle or inferior lateral medullary arteries.
 ON THE SIDE OF LESION:
1. Pain, numbness, impaired sensation over one half of face:
descending tract and nucleus of 5th nerve.
2. Ataxia of limb, falling to the side of lesion: restiform body,
cerebellar hemisphere, cerebellar fiber, spinocerebellar tracts.

42. 4. Nystagmus, nausea, vomiting, vertigo: vestibular nucleus(8th)
5. Horner’s syndrome: descending sympathetic tract.
6. Dysphagia, hoarseness, paralysis of palate and vocal cord:
issuing fiber of 9th and 10th nerve.
7. Numbness of ipsilateral arm, trunk or leg: cuneate and gracile
nuclei.
 ON SIDE OPPOSITE TO LESION:
1. Impaired pain and temperature over half the body:
spinothalamic tract

43. MEDIAL MEDULLARY
SYNDROME
(dejerine anterior bulbar syndrome)
• Occurring due to involvement of basilar artery or
occlusion of vertebral artery.
AFFECTED STRUCTURE SYMPTOMS
12TH NERVE NUCLEI Tongue deviation to same side
MEDIAL LEMINISCUS Loss of joint position sense and
vibration on opposite side
PYRAMIDS Weakness of opposite side limbs

44. VENOUS DRAINAGE OF
BRAIN
• Venous drainage of brain is by two type of
vessels – sinuses and veins. Sinuses are vessels
between meningeal layers and periostium. They
are not true blood vessels and site outside dura.
• Veins are true blood vessels. Separated into two
2 system : 1) Superficial cerebral vein- around
superficial surface of hemisphere under Dura in
subarachanoid space draining the hemisphere.
• 2) Deep vein – drain subcortical matter and
white matter around lateral ventricle.

46. • Principle sinus is the Superior Saggital Sinus (SSS) in the
falx cerebri. Superficial cerebral vein drain into SSS via
venous lacunae.
• Superior middle cerebral vein travel along lateral sulcus and
then drain into cavernous sinus which then drain into
sigmoid sinus via inferior petrusal sinus .
SUP. SAGGITAL SINUS
CONFLUENCE OF SINUSES
RIGHT AND LEFT LATERAL SINUSES
SIGMOID SINUS

47. DEEP VENOUS SYSTEM
• Inferior saggital sinus along superior surface of corpus
callosum running parallel to superior saggital sinus.
• Internal cerebral vein run along the top of the third ventricle to
form great cerebral vein ( great vein Galen ) .
• Inferior sagital sinus
STRAIGHT SINUS
LATERAL SINUS
SIGMOID SINUS
INTERNAL JUGULAR VEIN
Anterior cerebral vein (travel along ACA ) drains medial and
inferior part of hemisphere which the drain into deep middle
cerebral vein to form BASILAR vein which drains into great
vein Galen via internal cerebral vein .

49. Spinal cord anatomy
 It is 46 cm in length.
 Extends from lower medulla to lower border of L1.
 whereas dura or arachnoid matter upto S2.
 piamatter attach to coccyx.
 Conus- it is lower most portion of spinal cord.
(S3,4,5,cx)
 Epiconus-just above the conus.
(L4,5,S1,2)
 Cauda euina-roots below L2.

51. Blood supply of spinal cord
 Anterior spinal artery- branch of vertebral artery.
Single in number.
Supplies anterior 2/3rd of spinal cord.
 Posterior spinal artery- branch of vertebral/PICA.
2 in numbers.
Supllies posterior 1/3rd of spinal cord.
 Radicular artery/radiculomedullary artery.
 Artera radicularis magna(artery of adamkiewicz)
arises from aorta
unilateral,usually from left side.
In the lower thoracic or the upper lumbar levels(T9 and
L2)
supplies the lumbar enlargement.

56. Brown sequard syndrome
 Most common in extramedullary lesion.
 BELOW LEVEL-
C/L loss of pain and temp.(lat spinothalamic tract)
I/L proprioceptive
I/L UMN
 AT LEVEL-
I/L loss of pain and temp.
I/L proprioceptive
LMN

57. Central cord syndrome
 Causes-
hyperextension injury(men in barrel type)
central mass
syringomyelia
 Arm weakness out of proportion to leg weakness
 dissociated sensory loss(loss of pain and temp.
sensations over the shoulders,lower neck, and upper
trunk(cape distribution)

58. THANK YOU!!
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