Cerebrovascular Anatomy

M. Christopher Wallace M.D.

The Toronto Western Hospital,

University Health Network

University of Toronto

Postgraduate Lecture Series

Division of Neurosurgery

Friday October 6, 2000

Collateral Circulation

• Circle of Willis• Variation• Leptomeningeal

Collateral

Cerebral Autoregulation

• Maintenance of blood flow during variation in blood pressure

• Change in blood flow related to metabolic activity

Mechanism for Cerebral Autoregulation?

• Myogenic

• Neurogenic

• Metabolic

Measurement of Cerebral Blood Flow

• Seymour Kety• Delivery of blood flow to given wt of brain per

time period– 50ml/100grams/minute

Brain takes 12-15% of cardiac output

Internal Carotid Artery

• Divisions: cervical, petrous, cavernous, infraclinoid, supraclinoid

• Branches: meningohypophyseal trunk• dorsal meningeal artery, tentorial artery, inferior

hypophyseal

• artery of the inferior cavernous sinus

• capsular arteries of McConnell

Internal Carotid Artery

Internal Carotid Artery

• Supraclinoid

• Branches – Ophthalmic– Posterior communicating– Anterior choroidal

Bifurcation

Middle Cerebral Artery

• Variation

• Divisions (M1-M4)

• Lenticulostriate arteries

– medial

– lateral• putamen, caudate, sup

internal capsule

Anterior Cerebral Artery

• Variation• Divisions (A1-A4) • Anterior communicating artery

• Lamina terminalis, septal region, fornix, preoptic/hypothalamus

Recurrent artery of Heubner

Anterior putamen, pallidum and internal capsule