Transcript Neuroanatomy: Blood Supply

SCRUBS Neuroanatomy Workshop
Blood Supply to the Brain
Jake Ahmed
[email protected]
Introduction
• Anatomy overview
• Intracerebral supply
– Anterior Circulation
– Posterior circulation
– Territories of supply
• Strokes
• Classification
• Presenting features
• Summary
R Subclavian A.
R
O
A
T
A
L Internal Carotid A.
R Internal Carotid A.
L V e r t e b r a l A.
R Common Carotid A.
L Common Carotid A.
Anterior
Circulation
R V e r t e b r a l A.
Anatomy Overview
Posterior
Circulation
Circle of Willis
Anterior Cerebral A.
anterior communication a.
Middle Cerebral A.
Anterior
Circulation
Origin
posterior communication a.
Superior Cerebellar A.
Pontine a.
Anterior-Inferior Cerebellar A.
Posterior-Inferior Cerebellar A.
Posterior
Circulation
Origin
Circle of Willis
(Double thumbs-up of Ahmed)
Anterior Cerebral A. = ACA
Middle Cerebral A. = MCA
L-MCA
Posterior Cerebral A. = PCA
R-MCA
Superior Cerebelllar A. = SCeA
Anterior-Inferior Cerebellar A. = AICeA
L-VA
Posterior-Inferior Cerebellar A. = PICeA
Vertebral A. = VA
R-VA
Arterial Territories
Striate & Choroidal
Striate
Medial – from ACA
Lateral – from MCA
Choroidal
Anterior – from ICA
Posterior – from PCA
ANTERIOR
CIRCULATION
SUPPLY
ACA
MCA
PCA
SCeA
AICeA
PICea
POSTERIOR
CIRCULATION
SUPPLY
Overview of blood supplies & territories
Lobes of the brain
Strokes
The outcome of compromised blood supply to the brain
Clinical Definition
Deficit: Focal neurological
Onset: Sudden
Origin: Vascular
Duration: >24 hours
TIAs = Strokes that last <24hours
Bamford Classification of Strokes
TACS =
PACS =
LACS =
POCS =
Total Anterior Circulation Syndrome
Partial Anterior Circulation Syndrome
Lacunar Syndrome
Posterior Circulation Syndrome
Also classified on compromised factor
Ischaemic Stroke
80%
Thromboembolic
Atherosclerotic
Haemorrhagic Stroke
20%
Worse outcome (usually)
MCA
occlusion
Hemispheric
haematoma
TACS
PACS
HEMIPARESIS
2/3 of criteria
For TACS
HOMONOMOUS HEMIANOPIA
DYSPHASIA/INATTENTION
LACS
4 classical syndromes
OR any of these 3
Isolated cortical dysfunction
Loss of proprioception in 1 limb
Monoplegia
Distal
MCA
occlusion
Distal
ACA
occlusion
POCS
Isolated visual field deficit
Cortical
perforation
Vessels
(from MCA)
1. Pure motor hemiparesis
2. Pure hemisensory loss
3. 1+2 together
4. Ataxic hemiparesis
(ipsilateral corticospmal and cerebellar- like dysfunction
due to supratentorial and brainstem lesions)
Opthalmoplegia
Cerebellar signs (PIGHAND)
Cranial nerve palsy + contralateral
motor/sensory deficit
Cortical
perforation
Vessels
(from MCA)
Meningeal Bleeds
Extradural
Meningeal arteries
Pterion = anatomical weak-spot
Hx of trauma / LoC / Lucid period
Sub-dural
Bridging veins across subdural space
Acute/Subacute(3-7/7)/Chronic(2-3/52)
At risk groups
Infants
Alcoholics
Elderly
Pts on Anticoagulants
Subarachnoid
Cerebral arteries
Berry aneurysm rupture/burst
THUNDER CLAP HEADACHE
Xanthochromic CSF 12h later
Linked to ADPKD
Summary
•
Anatomy overview of Blood supply to the brain
•
Circle of Willis (Double thumbs-up of Ahmed)
•
Territories of different arteries
•
Strokes
– Definition
– Classifications
– Presenting features to clinically distinguish types
•
Meningeal Bleeds