Acute Stroke and TIA Flashcards
If someone presented with clinical features suggestive of a stroke, what would you do?
- ABCDE
- History - Exact onset, changes/progression, Risk factors
- Examination - full neuro exam, CVS, systemic and risk factor exam
When would you treat hypertension in someone presenting with a stroke?
- Hypertensive emergency (encephalopathy/aortic dissection)
- If thrombolysis is being considered
How long after presentation with symptos of a stroke should someone get a CT head?
Within 1 hour
When is CT/MRI within the first hour of presentation with stroke sypmtoms essential?
- If thrombolysis considered
- High risk of haemorrhage
- Unusual presentation - fluctuating consciousness
What is the most sensitive imaging modality for detecting acute infarction?
Diffusion-weighted MRI
What happens at a cellular level when cerebral infarction occurs?
Hypoxic damage:
-
Na+/K+ pump Fails -> Na+ accumulates in the cell -> osmotic shift into cell -> cellular swelling
- Cells in the immediate area around the infarct die very quickly, as they swell and burst. Cells in “penumbra” are relatively less oematous, and can be “saved”
-
Excitotoxicity - Damage as a result of prolonged depolarisation of cells in affected area
- Results in failure of AMPA and NMDA receptors - allows excessive calcium into the cell. This causes release of free radicals, production of cytokines, and direct apoptotic effects in the penumbra
What specific things might you look for on examination in someone presenting with features of a stroke?
Assess extent and localise
- Thorough, full neruo exam - clinical diagnosis and lesion localisation
Look for risk factors
- Pulse (AF)
- Heart sounds (valve disorders)
- Carotid Bruit
- Signs of PVD
- Bruising/Bleeding
- Xanthalasma/Xanthoma/Corneal arcus
- Tar Staining
When would you consider thromblysis in someone presented with a stroke?
Once haemorrhage has been excluded as cause, and within 4.5 hour window of onset (benefits outweigh risks within this window)
Within what time frame are the best results achieved using thrombolysis?
Within 90 minutes of onset
What thrombolytic agent is most commonly used in stroke management?
Alteplase
What are contraindications to thrombolysis in a stroke?
Look them up - Impossible to remember all of them!!! - think of categories of contraindications
- Stroke related
- Neurological
- Bleeding tendency
- Trauma
- Medical problems
What are stroke related contraindications to thrombolysis
- Rapidy improving symptoms
- Ischaemia of >1/3 MCA territory
- Symptoms suggestive of SAH
- Seizure at start of stroke
What are neurological contraindications to thrombolysis?
History of intracrnal bleed, aneurysm or neoplasma
Spinal or cranial surgery/injury
What bleeding tendency risk factors are contraindicaitons to thrombolysis?
- Significant bleeding disorder
- Therapeutic anticoagulation - LMWH, DOACs, Warfarin
- Iron deficiency anaemia
- Thrombocytopenia
- Advanced liver disease
If thrombolysis was contraindicated, what treatment would you start someone on for acute treatment of a stroke?
Aspirin PO/PR OD for 2 weeks or
Clopidogrel 300mg PO STAT, then 75 mg OD
What are trauma related contraindications to thrombolysis in stroke?
- Significant head injury <3 months
- Major surgery/delivery/external heart massage <2 weeks
- Puncture of non-compressible blood vessel <2 weeks
What medical problems are contraindications for thrombolysis in stroke?
- SBP > 180/DBP >110
- Active internal bleeding
- Aortic aneurysm
- Bacterial endocarditis/pericarditis
- Acute pancreatitis
- Haemorrhagic retinopathy
- Oesophageal varices
- Ulceratie GI disease <3 months
- GI/GU haemorrhage < 3 weeks
Why does diffusion weighted MRI detect early abnormalities seen in infarction better than normal MRI or CT?
This type of MRI exploits the fact that damaged cells fill with water – and thus contain more water than normal cells in the early stages of damage.
What intial investigations would you consider doing in someone presenting with a stroke?
- CT/MRI - within 1 hour
- MRI angiography
- ECG
- CXR
- Bloods - ESR, FBC, clotting screen, glucose, Lipids/cholesterol
Why might you do an ESR on someone presenting with features of a stroke?
If with headache and tender scalp - Giant cell arteritis
Why might you do FBC or clotting in someone presenting with a stroke?
Look for evidence of clotting/bleeding disorders - thrombocytopenia, polycythaemia
What would you want to prioritise in your ABCDE assessment in someone presenting with a stroke?
- Maintain airway
- Prevent hypoxia
- Hydrate
- Treat fever / source of fever – this can help to limit the extent of damage
- Treat hypo / hyperglycaemia
What dose of aspirin would you give someone if thrombolysis was contraindicated?
300 mg
How long would you put someone on aspirin treatment for following a stroke?
2 weeks
If someone presented with a TIA with amaurosis fugax, where might the occlusion be taking place?
Retinal artery occlusion
What dose of clopidogrel would you give someone as long-term prophylaxis?
75 mg OD
What could you give someone if they did not tolerate clopidogrel for post-stroke prophylaxis?
Slow-release dipyridamole
What is the definition of a transient ischaemic attack?
A brief episode of neurological dysfunction due to temporary focal cerebral or retinal ischaemia without infarction, e.g. a weak limb, aphasia or loss of vision, usually lasting seconds or minutes with complete recovery. TIAs may herald a stroke. The arbitrary time of <24 hours is no longer used.
What are causes of TIA?
- Atherothromboembolism
- Cardioembolism - Mural thrombus, AF, Valve disease
- Hyperviscosity - polycythaemia, sickle-cell, myeloma
- Vasculitis - cranial arteritis, SLE, PAN
What are features of an anterior circulation TIA?
Carotid system
- Amaurosis fugax
- Aphasia
- Hemiparesis
- Hemisensory loss
- Hemianopic visual loss
What are features of a posterior circulation TIA?
- Diplopia, vertigo, vomiting
- Choking and dysarthria
- Ataxia
- Hemisensory loss
- Hemianopic visual loss
- Bilateral visual loss
- Tetraparesis
- Loss of consciousness (rare)
- Transient global amnesia (possibly)
If, on examination of someone presenting with signs of a TIA, you found there to be central retinal artery occlusion, where might this suggest there is stenosis in the carotid system?
Internal carotid artery stenosis
What scoring system could you use to stratify those who have had a TIA who might be at higher risk of stroke in the future?
ABCD2 score - score >/=4 indicates high risk of early stroke - assess by specialist in 24 hours
What differentials would you want to consider in someone presenting with features of a TIA?
- Hypoglycaemia
- Migraine aura
- Focal epilepsy
- Hyperventilation
- REtinal bleeds
- Malignant hypertension
- MS
- Intracrnaial tumours
- Peripheral neuropathy
- Phaeochromocytoma
- Somatization
What investigations would you consider doing in someone with a suspected TIA?
- Bloods - FBC, U+E’s, Glucose, Lipids
- CXR
- ECG
- Carotid doppler +/- angio
- CT/Diffusion weight MRI
- ECHO
How would you manage someone with a TIA?
- Control risk factors - BP, DM, Hyperlipidaemia, Smoking
- Antiplatelet therapy - Aspirin (300mg) for 2 weeks, then clopidogrel (75mg) long-term
- Consider anticoagulation - AF
- Consider carotid endartectomy - within 2 weeks of presentation if >70% stenosis and no contrindiations
How long after a TIA are individuals not allowed to drive?
1 month - Need to inform DVLA if stll symptomatic after 4 weeks or HGV driver
What risk factors would you ask about in the history of someone with a suspected stroke?
- Smoking
- HTN
- Diabetes
- AF
- CVS disease
How soon after TIA symptoms present would you want to get specialist review?
24 hours
What procedure would you consider doing following a TIA?
Carotid endarterectomy
What type of strokes is acute severe hypertension treated in?
Haemorrhagic, not ischaemic!!!
In the long terms, what investigations might you consider doing in someone who has had a TIA?
- ECG
- 24-hour tape
- ECHO +/- bubble study - patent foramen ovale
- Vasculitis screen
- Thrombophilia Screen
How long after a stroke would you start statin therapy?
48 hours
What medications would you start someone on as long term therapy following stroke/TIA?
- Antihypertensives
- Clopidogrel 75 mg OD - after 2 week therapy
- Statin
What specific medication would you consider putting someone on if their stroke was caused by AF?
Warfarin/DOAC
