This lecture was presented to the Osteopathic students at the Pacific Northwest University of Health Sciences in Yakima Washington.

1. DR. MICHAEL THOMAS
CEREBRAL VASCULAR ANATOMY

2. Chapter 8
Cerebral vascular system
Causes of vascular compromise
Internal carotid system
Vertibrobasilar system
Arteries and infarcts
Circle of Willis
Veins
Spinal cord blood flow
The blood-brain barrier
Focus on these aspects:
1. Classification of bleeds
2. Principal branches and areas supplied by the internal carotid system
3. The vertebral and basilar arteries and the associated areas
4. Anastomoses between ICS and VBS
5. The circle of Willis
6. Superficial and deep venous drainage of the brain
7. The blood-brain barrier

3. HEMODYNAMICS
 BRAIN REQUIRES 20% OF TOTAL BODY O2
 CEREBRAL BLOOD FLOW IS16% OF CARDIAC
OUTPUT
 CEREBRAL PERFUSION PRESSURE (CPP) –
MUST BE GREATER THAN 50mmHg TO
MAINTAIN CELLULAR INTEGRETY
 IRREVESIBLE BRAIN DAMAGE OCCURS AFTER
4 MIN OF CIRCULATORY ARREST

4. CPP=MAP-ICP
NORMAL ICP <20 mmHg
MAP-mean arterial pressure

5. ANTERIOR CIRCULATION
 ICA –INTERNAL CAROTID ARTERY
 ACA –anterior cerebral artery
 Acom – anterior communicating artery
 MCA – middle cerebral artery

6. POSTERIOR CIRCULATION
 VERTEBROBASILAR SYSTEM
 PICA – posterior inferior cerebellar artery
 AICA – anterior inferior cerebellar artery
 SCA – superior cerebellar artery
 PCA – posterior cerebral artery
PRIMARY SOURCE OF BLOOD FOR BRAIN
STEM AND CEREBELLUM

7. INTERNAL CAROTID ARTERY SEGMENTS
 CERVICAL – common carotid bifurcation to skull base
 PETROUS –encased by petrous portion of temperal bone
 CAVERNOUS – contained within cavernous sinus
(hypophyseal and meningeal branches)
 CEREBRAL – cavernous carotid to terminus
(opthalmic, posterior communicating, and anterior choroidal
arteries)

8. 4 Main Branches of the Internal Carotid Artery and Sub-branches
Posterior communicating
artery.Usually small artery that connects to
Frontal branches
the vertebral system
Parietal branches
Anterior choroidal artery.Small
artery that supplies the optic track (anterior
choroidal artery syndrome), and internal
capsule
Middle cerebral artery. The major
branch. Supplies most of superolateral
surface of the hemispheres
M1 + lenticulostriate (sylvian cistern) internal
superior and inferior
M2 insular cortex
M3 opercular (over the insula)
M4 cortical
Anterior cerebral artery. Other major
branch. Supplies the medial surface of the
frontal and parietal cortex and corpus
callosum
A1 cistern of the lamina terminalis
A2 infracallosal
A3 precallosal
A4 supracallosal
A5 postcallosal
Temporal branches
Anterior communicating
artery. Short stout channel
between the two anterior cerebral
arteries near their origin
Frontopolar arteries supply
anteromedial frontal lobe.
Pericallosal artery sweeps
posterior just superiorly to the
corpus callosum
Callosomarginal artery
usually in the cingulate sulcus

9. ACA
MCA
Larger in 70%
Ophthalamic
Post communicating
Anterior choroidal
Pierces dura
Hypophysial and
meningial
Carotid canal

10. Coronal section middle cerebral artery
Supply basal ganglia and internal capsule

11. Dorsal surface branches

12. Medial surface of hemispheres and inferior surface of temporal lobe
border

13. MCA M4 surface segments

14. Regions served by ACA / MCA / PCA

15. VERTEBRAL ARTERY
 4 SEGMENTS V-1 TO V-4
 V-1 ORIGIN SUBCLAVIAN TO C-6
TRANSVERSE FORAMEN
 V-2 C-6 TRANSVERSE FORAMEN TO C-2
 V-3 C2 TO ATLANTO-OCCIPITAL
MEMBRANE
 V-4 TRAVERSES DURA TO UNITE WITH
OPPOSITE VERTEBRAL ARTERY

16. The vertebrobasilar artery system.
Supply spinal cord, brainstem, cerebellum,
and posteroinferior cerebral hemisphere.
1. Spinal arteries branch from the vertebral.
Anterior and posterior spinal artery
Basilar
2. Posterior inferior cerebellar artery
branches from each vertebral artery.
Supplies lateral medulla and PI cerebellum
3. Basilar artery formed from union of two
vertebral arteries
4. Basilar artery ends in bifurcation into
paired posterior cerebral arteries

17. PICA
 LOCATION CISTERNA MAGNA
 MAJOR BLOOD SUPPLY TO THE MEDULLA
 POSTERIOR SPINAL ARTERY USUALLY
BRANCHES FROM PICA
 POSITIONED NEXT TO CRANIAL NERVES
9, 10, AND 11

18. AICA
 BLOOD SUPPLY TO VENTRAL-LATERAL
CEREBELLUM, PONS, CHOROID PLEXUS
 POSITIONED NEXT TO CRANIAL NERVES
7&8

19. SUPERIOR CEREBELLAR ARTERY
SUPPLIES MEDIAL, LATERAL, AND SUPERIOR CEREBELLAR CORTEX AND CEREBELLAR
NUCLEI AND MIDBRAIN
PASSES JUST CAUDAL TO CN III THROUGH AMBIANT CISTERN

20. PCA
 P-1 – FROM BASILAR BIFURCATION TO PCOM (
GIVES OFF SMALL BRAINSTEM FEEDERS)
 P-2 – FROM PCOM TO INFERIOR TEMPERAL
BRANCHES ( GIVES OFF SMALL THALAMOGENICLATE BRANCHES)
 P-3 – PORTION THAT GIVES RISE TO TEMPERAL
BRANCHES
 P-4 – BRANCHES MEDIAL FORMING
CALCARINE AND PARIETAL-OCCIPITAL
ARTERIES

21. DORSAL BRAINSTEM VIEW

22. VENTRAL BRAINSTEM VIEW

23. The circle of Willis. A series of arteries that provides
anastomotic communication between the left and right arterial
trees and between the internal carotid and vertebral systems
1.
2.
3.
4.
5.
Anterior communicating artery
Anterior cerebral artery
Internal carotid artery
Posterior communicating artery
Posterior cerebral artery
Ganglion arteries (not shown)
branch from the circle of
Willis and supply
diencephalon and base of
telencephalon
Segments of the anterior
and posterior cerebral
arteries

24. DEEP GANGLIONIC PERFORATING ARTERIES

25. Spinal cord blood supply
3 MAIN ARTERIES
-ANTERIOR SPINAL ARTERY
- 2 POSTERIOR SPINAL
ARTERIES
- ADAMKIEWCZ- ORIGIN IS
LEFT SPINOMEDULLARY
ARTERY T-12 – L1 SUPPLIES
LOWER THORACIC AND
UPPER LUMBAR CORD

26. Venous Circulation

27. CEREBRALVENOUSCHARACTERISTICS
 MULTIPLE ANASTOMOTIC CHANNELS
 MULTIPLE VENOUS SINUSES
CAVERNOUS,PETROSAL, SUPERIOR,
INFERIOR, STRAIGHT, TRANSVERSE,
SIGMOID
 NONVALVULAR SYSTEM
 4 UNPAIRED VEINS
SUPERIOR SAGITAL SINUS, INFERIOR
SAGITAL SINUS, VEIN OF GALEN,
STRAIGHT SINUS

28. DIVISIONS
1.
BASAL VIENS
(LATERAL SINUS,
ROSENTHAL,
PETROSAL SINUS,
CAVERNOUS SINUS)

29. 2. CEREBRAL –
(SUPERIOR SAGITAL SINUS,
ANASTOMOTIC VEINS - TROLARD,LABBE,
SUPERIOR MIDDLE CEREBRAL VEIN

30. 3. INTERNAL VEINS – DRAIN INTO THE VEIN
OF GALEN

31. Galen
Vein of
Straight sinus
VEIN OF GALEN
MALFORMATION

32. Blood Brain Barrier

33. BLOOD BRAIN BARRIER
- PHYSIOLOGICBARRIERPREVENTS
MOVEMENT
OF HIGH MOLECULAR WEIGHT MOLECULES
- ABSENT FENESTRATIONS
- TIGHT JUNCTIONS

34. REGIONS WITH NO BBB
1. AREA POSTREMA
2. PINEAL AND PREOPTIC RECESSES
3. TUBER CINEREUM
4. HYPOPHYSIS
5. CHOROID PLEXUS

35. BBB DISRUPTION
GLIOBLASTOMA MULTIFORME WITH
VASOGENIC EDEMA
BBB BREAKS DOWN UNDER
DISEASE STATES

36. CEREBRAL SPINAL FLUID
PRODUCTION & ABSORPTION

37. SUPERIOR SAGITAL SINUS OCCLUSION FROM MENINGIOMA

38. Causes of vascular compromise:
A. Aneurysm
small (berry or saccular)
large >2cm
fusiform (elongated)
85% ICA system
15% VB system
B. Embolism
thrombus – blood
transient ischemic attack
septic emboli
C. arteriovenus malformation
teens and young adult
share some features of
neoplasm
1. dynamic
2. lead to hemorrhage

39. SUBARACHNOID HEMORRHAGE
 CLOSED HEAD INJURY MOST COMMON ETIOLOGY
 ANEURYSM RUPTURE ALMOST ALLWAYS CAUSE SAH
 TRAUMATIC SAH OCCURS COMMONLY AT CONVEXITIES
 ANEURYSMAL SAH OCCURS COMMONLY IN BASILAR CISTRNS
 RARELY ANEURYSMAL SAH WILL EXTEND INTO THE
VENTRICLE
 MAY CAUSE HYDROCEPHALUS

40. SUBARACHNOID HEMORRHAGE
POSTERIOR
COMMUNICATING
ARTERY ANEURYSM

41. CEREBRAL ANEURYSMS
 85% ANTERIOR CIRCULATION
 OCCURS NEAR BRANCHING VESSELS
 CAN CAUSE COMPRESSIVE CRAINIAL
NEUROPAHTY(pcom aneurysm compressing
cn III causing ptosis AND PUPIL DILATION
 3 TYPES
SACCULAR
FUSIFORME
MYCOTIC

42. Common patterns of aneurysms: branches and tortuous turns
ICA system
VB system

44. ANEURYSM TREATMENT
 SURGICAL CLIP LIGATION
 ENDOVASCULAR COILING
 ANEURYSM BYPASS AND CLIP LIGATION
 COMBINATION COILING AND CLIPPING

45. Basilar Artery Apex
Aneurysm
Occipital AVM

46. The cavernous sinus
Aneurysm
Fistula

47. ARTERIAL VENOUS MALFORMATION
 DIRECT CONNECTION BETWEEN ARTERY AND





VEIN
CAPILLARY BED IS ABSENT
NO INTERVIENING BRAIN TISSUE
MEDIUM TO HIGH FLOW
USUALLY PRESENTS WITH HEMORRAGE OR
SEIZURE
PREGNANCY MAY CAUSE AVM TO GROW

48. AVM TREATMENT
SURGICAL RESECTION
 INDICATED IF ELEQUENT BRAIN IS NOT
INVOLVED
EMBOLIZATION
 ENDOVASCULAR TECHNIQUES MAY HELP
FACILITATE SURGERY. USUALLY REQUIORES
MULTIPLE PROCEDURES
RADIATION
 STEREOTACTIC RADIATION MAY BE USED FOR
COMBINATION
THERAPY
 ALL THREE TREATMENT OPTIONS MAY BE
SMALL AVMs.
USED FOR COMPLEX AVMs

49. AVM

50. ARTERIOVENOUS MALFORMATION

51. SUBDURAL HEMORRHAGE