stroke 1&2 Flashcards
how many hemispheres is the cerebrum split into? and what are they?
split into 2 hemispheres- dominant and non-dominant
what does each side of the cerebrum control?
Dominant side–Speech–Language–Rational thinking
Non dominant side–Intuition/Insight
what is the frontal part of the brain for?
•FRONTAL–Reasoning and judgment
what is the parietal part of the brain for?
PARIETAL–Motor/sensory for contralateral side
what is the cerebellum used for?
CEREBELLUM–Balance/posture
what is the brainstem used for?
BRAINSTEM–Medulla controls respirations and heart rate
what are the 4 lobes in the brain?
occipitical/ frontal/ parietal/temporal
what does the occipital lobe do?
OCCIPITAL–Visual experience including experience of colour, motion, depth of perception, pattern, form and location in space
what does the temporal lobe do?
TEMPORAL–Auditory association or perception and long term memory recall
what are the 6 functions of the brain?
regulatory center / seat of consciousness / sensation/Source of voluntary acts •Seat of emotions •Higher mental processes
how much cardiac output does the brain receive?
20%-800 to 1000 mL per minute
what is the primary regulator for CNS blood flow?
CO2- primary vasodilator in the CNS
ensures adequate blood supply
what are the brain supply blood features?
Continuous oxygen requirement- if not death
high oxygen supply
Neurons - Predominantly aerobic
Sensitive areas:–Adults -Hippocampus, 3,5th& 6thlayer of cortex
children- brain stem nuclei
how much earlier do black Africans tend to develop a stroke?
10 years earlier
define stroke
is defined as a clinical syndrome, of presumed vascular origin, typified by rapidly developing signs of focal or global disturbance of cerebral functions lasting more than 24 hours or leading to death
what is a transient ischemic attack?
(TIA) is defined as an acute loss of focal cerebral or ocular function with symptoms lasting less than 24 hours and which is thought to be due to inadequate cerebral or ocular blood supply as a result of low blood flow, thrombosis or embolism associated with diseases of the blood vessels, heart, or blood
define Subarachnoid haemorrhage (SAH)
is a haemorrhage from a cerebral blood vessel, aneurysm or vascularmal formation into the subarachnoid space (the space surrounding the brain where blood vessels lie between the arachnoid and pia mater).
how does an SAH usually present?
sudden onset of severe headache and vomiting, with non-focal neurological signs which may include loss of consciousness and neck stiffness.
what are the two types of stroke you can get?
ischemic
SAH
What are the two types of ischemic stroke?
Thrombotic- blood blocks clot flow in the brain
–Embolic- clot/ fatty breaks down and allows it to flow to brain where it blocks an artery
what are the two types of Haemorrhagic strokes?
Intracerebral(within the brain)–
Subarachnoid(between the brain and the skull)
what happens in a local infraction?
cell death is 6 min
what happens in a central infaction?
area orumbra, surrounded by a penumbra of ischemic tissue that may recover
define haemorrhage
Haemorrhage: Extravascular release of blood causes damage by cutting off connecting pathways, resulting in local or generalized pressure injury
if resolved in 24 hours what is it known as?
TIA-same as ischemic stroke(cerebral infraction )mostly due to blockage of cerebral artery ( 80%)
what is an Intracerebral haemorrhage?
due to rupture of the vessels into the brain substance (15%)
what is an Subarachnoid haemorrhage?
due to rupture ofvessels into the subarachnoid space (5%)
how does an ischemic stroke occur?
interruption of cerebral blood flow due to obstruction or rupture of an artery supplying blood to the brain tissue
what happens after an ischemic stroke occurs?
Suppression of electrical activity within 12– 15sec
•Inhibition of trans-synaptic excitation after 2- 4min
•Inhibition of electrical excitability after 4- 6 min
•Breakdown of metabolism shortly thereafter
does neurons and glia remain alive after an ischemic stroke?
remain alive but functionless for as long as 30 min before cellular death occurs
what happens to the perfusion pressure after arterial occlusion occurs?
fall in perfusion pressure
define Apoptosis
programmed cell death-triggered by ischemia, evolves over 2 hours
what does cerebral blood flow (CBF) depend on?
The occlusion of a large vessel (such as MCA) is rarely complete and cerebral blood flow (CBF) depends on the degree of obstruction, and collateral circulation
what are the factors that influence progression and extent of ischemic injury?
Complication of several disorders
•Atherosclerosis – most common
.•Hypertension, smoking, diabetes.
•Heart disease – Atrial fibrillation.
what are the 9 types of investigations for ischemic injury - to confirm its presence or absence?
CT of the brain without contrast –location/ext
.•Electrocardiogram -heart
•Chest x-ray -heart
•complete blood count, platelet count –hemat.
•PT, aPTT –coagulation
•Serum electrolytes –complications
•Blood glucose -DM
•Renal and hepatic chemical analyses –status
•National Institutes of Health Scale (NIHSS)score
what is the treatment for suspected TIA?
Suspected TIA:
•Aspirin 300mg immediately
•Assess within 24 hours
what is the treatment for confirmed TIA?
•Clopidogrel (300mg loading dose and 75mgdaily thereafter) and high intensity statin therapy (atorvastatin 20-80mg daily) started immediately.
+ antihypertensives -NICE
what is the treatment for ischaemic stroke?
Remove any obstruction and restore blood flow to your brain.
what is emergency treatment for ischaemic stroke?
Clot-busting drugs must start within three hours.
•Injection of a clot-busting (thrombolytic)drug —such as a tissue plasminogen activator (TPA) I.V e.g. alteplas
if allergic to aspirin, when having an ischaemic stroke, what do you give?
clopidogrel
if dypepsia when having an ischaemic stroke, what do you give?
PPI
when do you use the CHA2DS2-VASc stroke risk score?
symptomatic or asymptomatic paroxysmal, persistent or permanent atrial fibrillation
•atrial flutter
•a continuing risk of arrhythmia recurrence after cardioversion back to sinus rhythm
when do you use the HAS-BLED score?
to assess the risk of bleeding in people who are starting or have started anticoagulation.
what do you offer if the person has a CHADVASC sore above 2?
offer anticoagulants- Prescribe warfarin or a direct oral anticoagulant drug
what anticoagulants do you not prescribe alone?
Do not prescribe aspirin or clopidogrel alone.
what is initiated by secondary care on diagnosis of ischaemic stroke or TIA without paroxysmal or permanent atrial fibrillation for long-term vascular prevention?
antiplatelet therapy
what is the antiplatelet therapy?- NB
The standard treatment is clopidogrel 75mg daily
Modified-release dipyridamole 200 mg twice daily may beused if both clopidogrel and aspirin are contraindicated or cannot be tolerated.
Aspirin 75mg daily may be used if both clopidogrel and modified-release dipyridamole are contraindicated or cannot be tolerated.
Aspirin 75 mg daily with modified-release dipyridamole 200mg twice daily may be used if clopidogrel cannot betolerated.
what is not recommend to people who suffer with an acute stroke? -lipid management
NOT statin-Continue statin treatment in people with acute stroke who are already receiving statins.
what lipid modification treatment is recommended for acute stroke?
A high intensity statin (such asatorvastatin 20–80mg daily)•The aim of statin therapy is to reduce non-HDL cholesterol by more than 40%-should clear within 3 months
where should statin treatment be avoided?
Statin treatment should be avoided in people with primary intracerebral haemorrhage unless advised for other indications.
what blood pressure aim- when taking antihypertensives?
present beyond 6 hours of symptom onset or have asystolic blood pressure greater than 220 mmHg
.•aim for a systolic blood pressure target of 130 to 140mmHg within 1 hour of starting treatment and maintainthis blood pressure for at least 7 days.
what is Carotid endarterectomy?
used to treat ischemic stroke
An incision in your neck to expose your carotid artery. The artery is opened, the plaques are removed, and then close the artery.
what is Angioplasty?
The balloon is inflated, compressing the plaques against your artery walls.•
A metallic mesh tube(stent)is usually left in the artery to prevent recurrent narrowing
what antiplatelet drug would you prescribe for ischaemic stroke?
Aspirin•300mg orally then combination of low-dose aspirin and the anti-platelet drug dipyridamole, to reduce blood clotting
•If aspirin can not be prescribed anti-platelet(allergic to or genuinely intolerant) drug clopidogrel
what anticoagulants would you prescribe for ischaemic stroke?
Heparin( short term- in hospital) and Warfarin(long term)
what is heparin?
A sulfated mucopolysaccharide stored in the secretory granules of the mast cells
high mol negatively charged
true/ false - as we increase the dose of asprin it becomes more toxic
true
what does ADP cause?
platelet activation
