Stroke Medicine Flashcards
What is a stroke?
Infarction or bleeding into brain manifests with sudden onset focal CNS signs due to hypoperfusion and action potential arrest
What are the types of stroke?
Ischaemic (85%), haemorrhagic (15%)
What are some causes of stroke?
Small vessel occlusion or thrombosis in situ
Cardiac emboli (AF, endocarditis, MI)
Atherothromboembolism
CNS bleeds
What are some risk factors for stroke?
HTN, smoking, DM, heart disease, peripheral vascular disease, carotid bruit
COCP, hyperlipidaemia, alcohol excess, ↑clotting
Describe the features of signs seen in stroke:
Worst at onset
Sudden, focal, predominantly negative
What scale can be used to assess the severity of a stroke?
NIH stroke scale
What conditions would be suggested by stereotyped stroke symptoms?
Capsular warning syndrome (intermittent hypoperfusion of lenticulostriate end arteries when MCA flow reduced)
Intracranial stenosis
What is the OCSP classification?
Classifies stroke into 4 syndromes: Total Anterior Circulation Syndrome Partial Anterior Circulation Syndrome Posterior Circulation Syndrome Lacunar Syndrome
What are the features of a TACS?
Hemiparesis AND higher cortical dysfunction AND homonymous hemianopia
What are the features of a PACS?
Isolated higher cortical dysfunction OR
any two of: hemiparesis, higher cortical dysfunction, hemianopia
What are the features of a POCS?
Isolated hemianopia, brainstem or cerebellar syndromes
What are types of lacunar stroke?
Pure motor Pure sensory Sensorimotor Ataxic hemiparesis Clumsy hand dysarthria
Which vessels tend to be occluded in TACS?
Proximal MCA or ICA
Which vessel tends to be occluded in PACS?
Branch MCA
Which vessels tend to be occluded in POCS?
Vertebral, basilar, cerebellar or PCA
Which vessels tend to be occluded in LACS?
Small penetrating arteries (usually lenticulostriate)
What is the acute management for stroke (scan, meds etc.)?
Protect airway
Screen swallow
Non contrast CT head or MRI head within 1hr
Aspirin 300mg once haemorrhagic stroke is excluded (continue for 2w)
Describe thrombolysis treatment and the indications:
Alteplase
Consider as soon as haemorrhage has been excluded and providing onset of symptoms was <4.5 hours ago
Best results within 90 mins
What should be done 24h after thrombolysis?
CT to identify bleeds
What are the complications of thrombolysis?
ICH, anaphylaxis, GI bleed
What are some contraindications to thrombolysis?
Haemorrhage, recent surgery or trauma, previous CNS bleed, aneurysm, stroke in past 3m, known clotting disorder, anticoagulants or INR > 1.7, BP > 180/105, intracranial neoplasm, LP in last 7d
How should intracerebral haemorrhage be managed?
BP control, correcting clotting derangement
Consider neurosurgery
What is act FAST?
Facial asymmetry, Arm/leg weakness, Speech difficult, Time to call 999
What are some examples of stroke mimics?
Subdural haematomas, brain tumours, MS
Migraine with aura, focal seizures, transient global amnesia, hypoglycaemia, sepsis, dehydration
What are some examples of stroke chameleons?
Venous infarcts, limb shaking TIA, occipital stroke
What are some post-stroke complications?
Recurrent stroke Immobility RICP Infections Mood and other cognitive issues Post stroke fatigue and pain
What is primordial prevention in regards to stroke?
Prevent onset of rf in general pop. e.g. stop smoking campaigns
What is primary prevention in regards to stroke?
Control rf in at risk groups
Look for and treat HTN, DM, hyperlipidaemia, cardiac disease, anticoagulation in AF
Help quit smoking, ↑exercise
What is secondary prevention in regards to stroke?
Control rf, lower BP and cholesterol (even if not
particularly raised)
Antiplatelets after stroke - 2w aspirin, then long term
clopidogrel
What is the MoA of aspirin?
COX1 inhibitor, suppressing prostaglandin and thromboxane synthesis
What is the MoA of clopidogrel?
Inhibits platelet aggregation by modifying platelet ADP receptors
What is the MoA of dipyradimole?
↑cAMP and ↓thromboxane A2
What is the target BP in stroke prevention?
130/80
How should carotid artery stenosis be investigated and when should pts have surgery?
Carotid Doppler US
If stenosis >70% (ECST) or >50% (NASCET), likely need carotid endarterectomy
What is the target HbA1c in stroke prevention?
<7%
What is the target total cholesterol in stroke prevention?
<3.5mmol/L
If cardiac source of emboli is suspected in stroke, what investigations can be done?
24h ECG for AF, echo
What score can be used to guide whether anti-coagulation is needed in AF patients due to risk of stroke?
CHA2DS2 VASc
What is a transient ischemic attack?
An ischaemic (usually embolic) neurological event with symptoms lasting <24h and without acute infarction
What are some causes of TIA?
Atherothromboembolism from carotid (primary causes)
Cardioembolism: mural thrombus, post MI, AF, valves
Hyperviscosity: polycythaemia, sickle cell
Vasculitis
What investigations should be performed in suspected TIA?
FBC, U+Es, glucose, lipids, CXR, ECG, carotid Doppler, CT/MRI, echo
What is the management for a TIA?
Control CV rf: HTN, lipids, DM, smoking
300mg aspirin for 2w then 75mg clopidogrel
Anticoagulation if cardioembolism
Carotid endarterectomy: within 2w if >70% stenosis
No driving for at least 1m
When can thrombectomy be used?
Within 6 hours of onset
Large artery occlusion in proximal anterior circulation
