Stroke Flashcards
The brain receives blood from 2 sources.
Name them.
1- Anterior circulation
2-Posterior circulation
What is the anterior circulation fed by? and what area of the brain does it supply?
- Fed by the internal carotid arteries
- Supplies most of the cerebral hemispheres.
What is the posterior circulation fed by? and what area of the brain does it supply?
- Fed by the vertebral arteries
- Supplies the brainstem, cerebellum, some of the temporal lobe and occipital lobe.
What are the 2 main vessels of the anterior circulation.
1-Anterior cerebral artery
2-Middle cerebral artery
What is middle cerebral artery a direct continuation of?
Is a direct continuation of the internal carotid artery.
Coritcal branches of the middle cerebral artery emerge from where to supply where?
- Emerge from the lateral fissure
- Supply the lateral aspect of the cerebral hemisphere, including the lateral parts of the frontal and parietal lobes as well as the superior temporal lobe.
What are the deep branches of the middle cerebral artery known as?
The lenticulostriate arteries
What structures do the lenticulostriate arteries supply?
They supply the deep grey matter structures including the lentiform nucleus, caudate nucleus and the internal capsule.
What is the anterior cerebral artery a branch of?
The internal carotid artery.
The left and right anterior cerebral arteries anastomose in the mideline via what?
The anterior communicating artery
Cortical branches of the anterior cerebral artery supply what?
The medial aspect of the frontal and parietal lobes
The anterior cerebral artery sends cortical branches to supply the medial aspect of the cerebral hemisphere. But it also has deep branches.
What deep white matter structure does the anterior cerebral artery supply?
The corpus callosum
The posterior circulation is composed of what main vessels.
1- Basilar Artery
2-Vertebral arteries
What vessel forms the posterior cerebral arteries?
The bifurcation of the basilar artery forms the posterior cerebral arteries.
What aspect of the brain does the posterior cerebral artery supply?
The occipital lobe,and the inferior aspect of the temporal lobe.
The posterior cerebral artery also has branches supplying the midbrain and the thalamus.
True or false
True
What forms the basilar artery?
The confluence of vertebral arteries.
What does the superior cerebellar artery supply?
The superior aspect of the cerebellum and midbrain.
What do the pontine arteries supply?
The pons - specifically the corticospinal tract; therefore if blocked can destroy the corticospinal tract and result in locked in syndrome.
What does the anterior inferior cerebellar artery supply?
The antero-inferio aspect of the cerebellum and the lateral pons.
What does the posterior inferior cerebellar artery supply?
The postero-inferio aspect of the cerebellum and the lateral aspect of the medulla.
Lenticulostriate arteries are deep branches of the middle cerebral artery. They supply deep brain structures and easily blocked resulting in lacunar strokes.
Explain why lacunar strokes are so variable in their presentation?
Because the lenticulostriate arteries supply many deep brain structures such as the thalamus, basal ganglia and internal capsule.
So depending where the infarct has occurred and what structure is deprived of blood will depend on the presentation seen.
e.g. thalamus- pure sensory stroke
internal capsule-pure motor stroke
The spinal cord has 2 main blood supplies.
State them.
1-Anterior spinal artery
2-Posterior spinal arteries
What does the anterior spinal artery supply?
Supplies the anterior ⅔rd of the spinal cord, including the spinothalamic tract and the corticospinal tract.
What do the posterior spinal arteries supply?
Supplies the posterior ⅓rd of the spinal cord. Including the dorsal column pathway.
If the anterior spinal artery is blocked what would be see?
- Would most likely have a bilateral affect as the artery is located along the midline.
- Would see loss of spinothalamic modalities below level of the blockage.
- Would also see upper motor neurone signs below level of the blockage due to ischaemia of corticospinal tract.
If the posterior spinal arteries were blocked, what would we see?
- Unilateral loss
- Get ipsilateral loss of dorsal column modalities below level of the blockage.
Lable the circle of willis.