Cerebral vasculature Flashcards
what percentage resources does brain use?
brain makes up 2% body weight
uses 10-20% cardiac output
20% oxygen consumption
66% liver glucose
what are the arteries leading to the brain?
what are the arteries in the circle of willis?
what is the venous drainage of the brain?
cerebral veins -> venous sinuses in dura mater -> internal jugular vein
where do the dural venous sinuses lie?
dural venous sinuses lie between the periosteal and meningeal layers of the dura mater
what are the different venous sinuses?
what are the types of intracranial hemorrhage?
extradural
subdural
subarachnoid
intracerebral
what are the factors of extradural haemorrhage?
trauma cause
immediate clinical effects (arterial high pressure)
high BP in arteries -> between meninges-middle meningeal artery (PTERION= weakness) -> rupture -> dura stripped -> skull compression
what are the factors of subdural clinical effects?
trauma causes
can be delayed clinical effects
slow accumulation of blood in subdural space -> rupture of veins
what is the cause of subarachnoid haemorrhage?
ruptured aneurysms- in subdural space where CSF flows
what is the case of intracerebral hemorrhage?
spontaneous hypertensive rupture of small vessels
what is the classic symptom of a subarachnoid haemorrhage?
thunderclap headache
what are the layers after the skull?
what is a stroke?
cerebrovascular accident (CVA)
rapidly developing focal disturbance of brain function of presumed vascular origin and of >24 hours
what are the types of CVA?
thrombo-embolic (85%) or haemorrhage (15%)
what is a TIA?
transient ischemic attack
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 ischemia?
- Lack of sufficient blood supply to nervous tissue resulting in permanent damage if blood flow is not restored quickly
- Not just oxygen- everything (e.g. glucose)
what are the factors of a thromboembolic stroke?
- Thrombosis
- Formation of a blood clot (thrombus)
- Embolism
- Plugging of small vessel by material carried from larger vessel
- E.g. thrombi from heart of atherosclerotic debris from internal carotid
what is the rate of disability following stroke?
50% permanently disabled
70% obvious neurological deficit
how common is a stroke?
3rd most common cuase of death
what are the symptoms of a stroke?
- Face- asymmetry, loss innovation one side
- Arms- any paralysis or weakness on one side
- Speech- any impairment
what are the risk factors for a stroke?
- Age
- Hypertension
- Cardiac disease
- Smoking
- Diabetes mellitus
what are the different perfusion fields for cerebral arteries?
what are the symptoms of anterior cerebral artery stroke?
- Paralysis of contralateral structures (leg>arm, face- also supplied by middle cerebral artery)
- Disturbance of intellect, executive function & judgement
- Breakdown frontal lobe function is known as abulia
- Loss of appropriate social behaviour
what are the symptoms of middle cerebral artery stroke?
classic stroke
- Contra lateral hemiplegia (arm>leg)
- Contralateral hemisensory deficits
- Hemianopia
- Aphasia (L-sided lesion)
what are the symptoms of posterior cerebral artery stroke?
- Visual defects
- Homonymous hemianopia
- Visual agnosia
- Prosopagnosia-inability to recognise faces
