Cerebral Vasculature Flashcards
How much weight does the brain make up?
2%
How much of the cardiac output does the brain use?
10-20%
How much of the oxygen does the brain use?
20%
How much of the liver glucose does the brain use?
66%
What is the process of venous drainage in the brain?
cerebral veins -> venous sinuses in the dura mater -> internal jugular vein (look at sinuses, circle of willis)
How would you get an extradural haemorrhage?
trauma, immediate clinical effects (arterial, high pressure)
How would you get a subdural haemorrhage?
- trauma, can be delayed clinical effects (venous, lower pressure)
- Space between dura and arachnoid
How would you get a subarachnoid haemorrhage?
ruptured aneurysms
How would you get an intracerebral haemorrhage?
spontaneous hypertensive - inside brain
What is a stroke?
- Cerebrovascular accident (CVA)
- “rapidly developing focal disturbance of brain function of presumed vascular origin and of >24 hours duration”
What are the two types of stroke?
thromboembolic + haemorrhage
How common is a thrombo-embolic stroke?
85%
How common is a haemorrhage stroke?
15%
What is a transient ischaemic attack (TIA)?
rapidly developing focal disturbance of brain function of presumed vascular origin that resolves completely within 24 hours
What is an infarction?
Degenerative changes which occur in tissue following occlusion of an artery
What is cerebral ischaemia?
Lack of sufficient blood supply to nervous tissue resulting in permanent damage if blood flow is not restored quickly
What is thrombosis?
formation of a blood clot (thrombosis)
What is an embolism?
plugging of small vessel by material carried from larger vessel e.g. thrombi from the heart or atherosclerotic debris from the internal carotid
What are the risk factors for a stroke?
- Age
- Hypertension
- Cardiac disease
- Smoking
- Diabetes mellitus
What are the symptoms in an anterior cerebral artery stroke?
- Paralysis of contralateral structures (leg more than arm or face)
- Disturbance of intellect, executive function and judgement (abulia)
3, Loss of appropriate social behaviour
What are the symptoms in a middle cerebral artery stroke?
- “Classic stroke”
- Contralateral hemiplegia: arm > leg
- (MCA also supply deep motor structures so may get complete hemiplegia on one side of body as deep structures taken out as well) - Contralateral hemisensory deficits
- Hemianopia
- Aphasia (L sided lesion)
What are the symptoms in a posterior cerebral artery stroke?
- visual deficits
- homonymous hemianopia
- visual agnosia
How does blood get to the head?
- Common carotid artery
- Internal carotid
- Vertebral artery
When is an extradural haemorrhage going to happen?
fracture pterion, middle meningeal rarely rupture (no pace between dura and skull) but because arterial high pressure constrict dura away from skull so raised intercranial pressure
