Stroke Flashcards
Name the classification system that assess stroke severity.
NIHSS - national institutes of health stroke scale
Name the oxfordshire community stroke project classifications.
TACS - total anterior circulation syndrome
PACS - partial anterior circulation syndrome
POCS - posterior circulation syndrome
LACS - lacunar syndrome
What is total anterior circulation syndrome?
The symptoms of a patient who clinically appears to have suffered a total anterior circulation stroke, but hasn’t had a diagnostic test yet
The symptoms are
- higher cortical dysfunction (dysphasia, visuospatial disturbances and decreased level of consciousness)
- homonymous hemianopia
- hemiparesis
What is the most common cause of TACS?
Proximal middle cerebral artery or internal carotid artery occlusion
What is partial anterior circulation syndrome?
The symptoms of a patient that suggests they have had a partial anterior circulation stroke. The symptoms are - isolated higher cortical dysfunction OR 2 OF - hemiparesis - higher cortical dysfunction - hemianopia
What is the most common cause of PACS?
Occlusion of a branch of the middle cerebral artery
What is posterior circulation syndrome?
The symptoms of a patient who clinically appears to have had a posterior circulation stroke The symptoms are - isolated hemianopia OR - brainstem syndrome
What is the most common cause of POCS?
Disruption of the posterior cerebral or cerebellar arteries
What is lacunar syndrome?
The symptoms of a patient who clinically appears to have had a lacunar stroke The symptoms ONE OF - pure motor stroke - pure sensory stroke - sensorimotor stroke - ataxic hemiparesis - clumsy hand-dysarthria
What is the most common cause of LACS?
Small vessel disease or a perforating artery in a small (<1.5cm) area of the brain
What are the two types of stroke?
Ischaemic stroke - blockage of blood vessels causing lack of blood flow to the affected area
Hemorrhagic stroke - rupture of blood vessels causing leakage of blood into the brain
Where is a normal place for a hemorrhagic stroke in hypertensive patients, and why?
In the perforating arteries branching directly off the middle cerebral artery
- the sudden change from wide blood vessel to small blood vessel, coupled with the hypertension, leads to a very sudden increase in pressure, causing the vessels to burst
- this is known as a hypertensive pattern of stroke
How are intracerebral haemorrhages treated?
ABCs Admit to the stroke unit Prevent haematoma expansion Neurosurgery (only when indicated) Treat pyrexia DVT prophylaxis - intermittent pneumatic compression stockings Nutrition and early rehab
How can haematoma expansion be prevented?
Reverse anticoagulants - prothrombin complex concentrate is better than fresh frozen plasma - reversal agent for dabigatran - vitamin K infusion for warfarin Lower BP
In what circumstances should an intracerebral haemorrhage be treated with neurosurgery?
When the haematoma is less than 1cm from the cortical surface
It’s a clinically deteriorating posterior fossa haematoma
Surgery done too early may be harmful
What can cause an ischaemic stroke?
Embolism (not often a thrombus like in MI)
- cardiac origins include AF, MI or a patent foramen ovale
- an atheroma from the aorta
- arterial origins include atheroma and dissection
Thrombosis
- large vessel disease (atherosclerosis)
- small vessel disease (lipohyalinosis and atherosclerosis)
Briefly describe the pathophysiology of an embolytic ischaemic stroke.
Blood clot forms and travels in the bloodstream up to the brain.
Once there it blocks an artery in the brain, preventing an area of the brain from being oxygenated, and thus causing ischaemia and tissue death
- cells burst and release calcium which activates lots of enzymes (cytotoxic storm)
- inflammatory response causes damage to the brain
Draw and label the circle of Willis.
Supplied by the two carotids and the two vertebral arteries
- the carotids supply become the middle cerebral arteries
- the vertebrals become the basilar artery
PICTURE
What is the ‘stunned’ area of brain that can be saved with fast reperfusion treatment?
Penumbra
- this area has slow blood flow, which allows it to be fully restored if blood flow is rectified
How should an ischaemic stroke be treated?
Thrombolysis - alteplase can be used up to 4.5 hours - 32% chance of benefit - small risk of brain haemorrhage Antiplatelets - 1st line if presenting after 4.5 hours - otherwise shouldn't be given before the 24 hour scan
What is endovascular therapy?
A guidewire is passed through the groin and into the brain.
A stent remover on the end is used to pull out the clot
What are the criteria for use of endovascular therapy in ischaemic strokes?
Availability
Received rtPA within 4.5 hours of the stroke
When the clot is in the internal carotid or middle cerebral artery
Patient is 18 or older
NIHSS >6
The brain scan shows a small core and good collateral (rescue) vessels
Onset to groin puncture is less than 6 hours
When can alteplase/rtPA not be used?
The patient is already on antiplatelets or they have a coagulopathy
They have a systolic BP of more than 185mmHg
What are the risk factors for an ischaemic stroke?
Age Hypertension Heart disease (including atrial fibrillation) Smoking Diabetes Hypercholesterolaemia Previous stroke/TIA Family history
What are the risk factors of an intracerebral stroke?
HYPERTENSION Cerebral amyloid angiopathy (high risk of recurrence) Anti-coagulants Anti-platelets Dementia Age Male sex Alcohol Smoking Drugs (cocaine, amphetamines) Hypocholesterolaemia Vascular lesions (aneurysms, AVMs, cavernomas)
Once someone has been treated for a stroke and they are recovering, what further investigations should be done?
Cardiac
- BP
- ECGs
- 72 hour ECG and loop recorder (trying to find AF)
- Echo (in some patients, to look for carotid stenosis)
Vascular
- carotid assessment
- CT angiogram/MR angiogram/doppler ultrasound
What prophylaxis treatments will people be put on after having an ischaemic stroke?
Antiplatelets
- reduces risk of secondary stroke by 22%
- clopidogrel = aspirin and dipyridamole (and is more effective than both)
- aspirin is more commonly used acutely is they arrive after 4 hours than as a discharge drug
Anti-hypertensives
Statins
Warfarin/NOACs
- used if the patient has AF
Carotid endarterectomy
- for carotid stenosis of more than 70%
What are the typical discharge drugs after a person has had an ischaemic stroke?
Clopidogrel or apixiban Simvastatin 40mg Perindopril 4mg (ACE inhibitor) Bendrofluazide 2.5mg (thiazide diuretic) Smoking cessations tools
