Stroke Flashcards
1
Q
what is stroke?
A
- syndrome characterised by rapidly developing clinical symptoms and/ or signs of focal loss of cerebral function lasting for more than 24 hours
2
Q
what is stroke due to?
A
- vascular origin
3
Q
what is a stroke less than 24 hours called?
A
- transient ischemic attack (TIA)
- mini stroke
4
Q
what is a mini stroke? (TIA)
A
- temporary ischemia due to attack/ disruption of the blood supply
5
Q
what may the mini stroke act as?
A
- may act as a warning sign of being predisposed to a stroke
6
Q
what many stroke deaths are there per year?
A
- 5.45 million stroke deaths per year
7
Q
how many stroke survivors are there?
A
- 9 million
8
Q
how many people with stroke die?
A
- 20 to 50%
9
Q
how many people are very affected from stroke?
A
- 1 in 3 people
10
Q
what does MCA stroke stand for?
A
- middle cerebral artery
- brain damage occurs due to disrupted blood flow in middle cerebral artery
11
Q
what does PCA stroke stand for?
A
- posterior cerebral artery
- can restrict the blood supply of multiple brain regions
12
Q
is MCA or PCA more common?
A
- MCA is more common
13
Q
what percentage of body weight is the human brain?
A
- it is 2% of body weight
14
Q
how much cardiac output goes to the brain?
A
- 15% of cardiac output goes to the brain
- 750 to 1000ml/ min
15
Q
what is the oxygen consumption of the brain?
A
- 20% of the whole boy
16
Q
how long does it take for the brain to shut down?
A
- 3 to 6 minutes
- blood supply is cut off
17
Q
how quick do the neurons shut down?
A
- shut down after 30-60 secons
18
Q
what happens to the patient when the brain shuts down?
A
- faint towards the floor as more blood can travel to the head
19
Q
what should you do to the patient when the blood supply is cut off?
A
- patient should be laying
- helps to restore blood supply
- elevate the legs to ensure more blood pumped to upper trunk
20
Q
where do arteries that supply the brain arise from?
A
- arise from the arch of the aorta
21
Q
what specific artery gives rise to different arteries?
A
- common carotid arteries
22
Q
what are the 9 main arteries?
A
- common carotid artery
- internal carotid artery
- external carotid artery
- anterior cerebral artery
- middle cerebral artery
- posterior cerebral artery
- vertebral artery
- subclavian artery
- basilar artery
23
Q
what do all the arteries form?
A
- form a complete circle
- called circle of willis
24
Q
where are the vertebral artery? what do they form?
A
- they are at the back
- they joint to form the basilar artery
25
what artery gives rise to the PCA?
- basilar artery gives rise to the posterior cerebral artery
26
what artery gives rise to the ACA and MCA?
- internal carotid artery
27
what happens if one artery is blocked?
- if artery is blocked on one side then the artery on opposite side is still viable
28
what do the communicating arches do?
- bridges between arteries to try push blood to the other side
29
what is the communicating artery?
- link between two main arteries to compensate and complete circle
30
what are the communicating arches of vertebral arteries?
- ACA connected via anterior communicating artery
- MCA and PCA linked via posterior communicating artery
31
what does the anterior cerebral artery supply?
- ACA supplies top of inner aspect
32
what does the middle cerebral artery supply?
- MCA supplies most of the lateral aspects
33
what does the posterior cerebral artery supply?
- posterior cerebral artery supplies the bottom aspects
34
what can a CT scan of a stroke patient identify? - give an example
- can use area of damage to identify which artery is blocked
e.g., blood clot in the middle aspect = ACA blocked
35
what problems may arise from ACA being blocked?
- motor problems
- sensory problems
36
what problems may arise from MCA being blocked?
- speech problems
37
what could go wrong in stroke patients?
- something inside could expand if there's a bleed and structures get crushed
38
what is an acute haemorrhagic stroke?
- no movement on one side
- as swelling comes down, some of the neurons start activating and the connections reorganise to allow some activity
39
what is an ischaemia stroke?
- loss of blood supply due to blockage
40
what can happen in the lateral stages of ischaemia strokes?
- gaps filled with fibrous or fluid
- lost action sense, just a collection of fluid
41
what is necrosis?
- death of brain cells
42
what are the four risk factors of ischaemic strokes?
- cardio- embolic
- atherothrombo- embolic
- small vessel disease
- others
43
what are the four aspects that cardio-embolic include?
- atrial fibrillation
- mural thrombus
- paradoxical embolism through patent foramen ovule
- infective endocarditis
44
what is a cardioembolic stroke?
- caused by blood clot or debris from the heart, blocking vessels
45
what are the four aspects of atherothrombo- embolic?
- carotid, vertebral, cerebral artery occlusion and carotid dissection
46
what is an atherothrombosis stroke?
- formation of a thrombus on an existing atherosclerotic plaque that dislodges and embolus blocks blood
47
where can an atherothrombosis stroke form? (4)
- carotid arteries
- vertebral arteries
- cerebral arteries
- where connected artery splits
48
what are the three aspects of small vessel disease?
- hypertensive arterial disease
- diabetic vasculopathy
- vasculitis
49
what is small vessel disease?
- walls of small arteries/ blood vessels are damaged, which affects the blood flow to the brain
50
what happens to the arteries in small vessel disease? (3)
- arteries become eroded, inflame or regenerated
51
what is the other risk factor of an ischemic stroke?
- venous thrombosis
52
what is venous thrombosis?
- rare condition where person lays down for a long time so the calf muscles aren't working and cannot pump the blood back to the heart
53
what happens in deep vein thrombosis? what should you check?
- blood is left stagnated and forms clots
- check if the calf muscle is swollen due to fluid accumulation
54
what is a haemorrhage?
- bleed into the brain causing blood flowing to crush the brain cells
55
what are the two types of haemorrhages?
- sub-arachnoid
- parenchymal
56
what is the sub- arachnoid?
- membrane that surrounds the brain and the spinal cord
57
what are the two aspects of sub- arachnoid?
- arterio venous malformation
- aneurysm
58
what is the parenchymal?
- essential functioning tissue of the brain, consisting of neurons, glial cells and blood vessels
59
what are the two aspects of parenchymal?
- hypertensive arterial disease
- amyloid angiopathy
60
what is the atherosclerotic etio- pathology?
- fatty streaks on the intimal layer of the wall
61
what happens if the bleed in the brain continues?
- holes will be drilled an the blood is drained out so that the brain can expand
62
what happens the more the blood is pushed down? what does this control?
- the more the blood is pushed down = more brainstem is pushed down
- brainstem controls all vital functions
63
what substances are present in the clinical presentation of atherosclerosis? (2)
- massive extracellular lipids (fatty deposits)
- fibrous plaques with deposits of platelets an fibrin
64
what happens to the arteries in atherosclerosis? what does this decrease?
- stiffness
- kinking of artery
- occlusion/ narrowing
- decreases perfusion pressure
65
what narrows in atherosclerosis? what does this reduce?
- lumen narrows
- reduces perfusion
66
what is a major risk for injury? what else does it increase?
- hypertension
- risk for injury, stretch to the walls and burst vessel
67
what people do blood clots form in?
- form in people with increased cholesterol, hypertension & diabetes
68
what do blood clots cause? what happens when it breaks?
- causes friction on the tubes as it accumulates and builds
- when build up breaks, it moves inside the arteries
69
what is thromboembolism risk factor?
- thrombus formation within the artery
70
what happens when the thrombus breaks down? what does it cause?
- when it breaks down, the embolus is pushed further upwards by the blood
- it then blocks small arteries and hence blocks any blood flow
71
what are the two other congenital risk factors?
- berry aneurysm
- arteriovenous malfunction
72
what is a berry aneurysm? what happens to it when blood is pumping?
- little pouch in the artery, which is weak
- when blood is pumping, the pouch is at risk of cracking and bleeding
73
where does berry aneurysm occur? (2)
- occurs in circle of willis
- as well as high pressure areas
74
what is arteriovenous malfunction?
- abnormal capillary bed as the arteries don't dissociate the oxygen so it continues into the waste as there's not enough capillaries
75
what comes in after an advanced stroke? what does this cause?
- sodium and potassium ions rush in, causing patient to use anaerobic mechanisms
- causes necrosis so debris accumulates
76
what is lost as neurons die?
- neuronal integrity lost
77
what does a mild- moderate stroke have inadequate supplies of?
- inadequate oxygen and glucose
- inadequate energy supply
78
what fails in mild to moderate stroke?
- failure of neuronal activity and regional brain dysfunction
79
what is there an influx of in severe stroke?
- influx of H20, Na+, Cl- and Ca+ causing anaerobic mechanisms to occur
80
what does severe stroke lead to? what accumulates?
- irreversible cellular injury
- lactic acid accumulates
- H+ compromises neuronal integrity
81
what is lost in advanced stroke? what does this cause?
- loss of function and accumulation of chemical influx of H20, Na+ and Ca+
- causes destruction of cells
82
what is penumbra? what does this provide a potential for?
- reversibly injured brain tissue around the ischemic core
- potential for recovery
83
what is a collateral circulation?
- network of blood vessels designed to preserve cerebral blood flow when primary route fails
84
when can brain start reactivating? what happens when the area of penumbra is activate?
- brain starts reactivating when the oedema comes down
- when area of penumbra activated an supplied with blood and glucose then you can remove more activity
85
what are the 9 risk factors of stroke?
- increased age
- males
- african americans
- diabetes mellitus
- prior stroke/ transient ischemic attacks
- family history of stroke
- asymptomatic carotid bruit (hear a murmur as blood flows through showing friction and clumping)
- geography/ climate
- socio- economic factors
86
what are the 5 major risk factors of stroke?
- hypertension
- high blood pressure
- heart disease, especially atrial fibrillation, angina
- cigarette smoking
- transient ischemic attacks
87
what are 5 secondary risk factors?
- increased serum cholesterol/ lipids
- physical inactivity
- obesity
- excessive alcohol intake/ drug abuse
- acute infection
88
how is stroke diagnosed?
- MRI shows specific cause and area shown
89
when is a CT scan not useful for stroke patients?
- not useful in early hours unless it is a huge bleed
90
what are the 4 factors that stroke prognosis depends on?
- type
- extent of lesion
- access to emergency care
- multidisciplinary input i.e., stroke physios and stroke nurses understand prognosis
