Transient ischaemic attacks (TIA) Flashcards
What initial investigations would you arrange for TIA?
- Chest radiograph
- Full blood count
- Blood glucose
- Blood lipids
- ECG
- Urea and electrolytes
- Liver function tests
- Skull x-ray
- Troponin levels
- ESR
The patient is hypertensive and a smoker and he needs further investigation for end – organ damage and other risk factors for atheromatous disease (especially diabetes and hyperlipidaemia). Skull x-ray is not indicated, nor troponin levels.
- Chest radiograph
- Full blood count -check for hypercoag e.g. polycythaemia
- Blood glucose
- Blood lipids
- ECG
- Urea and electrolytes
- Liver function tests
- ESR - check for risk of vasculitides
As well as urgent investigation of the cause for TIAs, this patient does require other treatment. Which of the following measures should be considered?
- Prophylactic low dose anticoagulant, e.g. Rivaroxaban 5mg OD
- Treatment of hypertension
- Treatment of hyperlipidaemia if present
- Treatment of diabetes if present
- Dietary advice
- Consider exercise regime once investigation/treatment TIAs completed to facilitate weight loss
- Advice on stopping smoking and reduction of alcohol consumption
- Introduction of an anti-platelet agent (e.g. Aspirin)
- Treatment of hypertension
- Treatment of hyperlipidaemia if present
- Treatment of diabetes if present
- Dietary advice
- Consider exercise regime once investigation/treatment TIAs completed to facilitate weight loss
- Advice on stopping smoking and reduction of alcohol consumption
- Introduction of an anti-platelet/anti-thrombotic agent (e.g. Aspirin)
Anticoagulation should not be used in this case.
Define TIA.
TIA’s are defined as: a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction
(updated from time-based definition to tissue-based because even short periods of ischaemia can cause pathological tissue changes)
What is the prognosis with untreated TIAs?
Without intervention, more than 10% patients will go on to have a stroke within a week.
What is the aetiology of TIA?
- Atherothromboembolism from the carotid is the chief cause: listen for bruits (though not a sensitive test).
- Cardioembolism: mural thrombus post-mi or in AF, valve disease, prosthetic valve.
- Hyperviscosity: eg polycythaemia, sickle-cell anaemia, myeloma.
- Vasculitis is a rare, non-embolic cause of TIA symptoms (eg cranial arteritis, PAN, SLE, syphilis, etc.).
What are the risk factors for TIA?
- AF
- Valvular disease
- Carotid stenosis (high risk >70%)
- Congestive heart failure
- HTN
- DM
- Smoking
- Alcohol
- Age
- PFO (patent foramen ovale)
- High chol
- Inactivity and obesity
- Hypercoagulability
What is the visual sign associated with TIAs?
Amaurosis fugax - retinal artery is occluded causing unilateral progressive vision loss “like a curtain descending”
Give 2 examples of global symptoms which are not associated with TIAs?
Syncope
Dizziness
Describe the signs and symptoms associated with TIAs.
- unilateral weakness or sensory loss.
- aphasia or dysarthria
- ataxia, vertigo, or loss of balance
- visual problems
- sudden transient loss of vision in one eye (amaurosis fugax)
- diplopia
- homonymous hemianopia
Other:
- single/many attacks of sudden onset breif duration
- Hx of cardiac disease/atherosclerosis
- Increased BP after event
- Carotid bruits
What does a crescendo TIA suggest?
“Crescendo” TIAs suggest a critical intracranial stenosis (commonly superior division of MCA)
What immediate investigations should you do for TIA?
Neurological examination - determine deficits
Bloods:
- FBC (excl. polycythaemia) + clotting profile, PT and PTT - if young and thrombophilia suspected
- Glucose
- Lipids
- ESR/CRP - excl. vasculitis
CT brain should not be done ‘unless there is clinical suspicion of alternative diagnosis that CT could detect’
- Urgent carotid doppler - evaluate need for carotid intervention
- ECG
- ECHO
Refer to TIA clinic within 24hrs + diffusion weighted and blood sensitive sequences MRI - SHOULD BE DONE ON SAME DAY AS SPECIALIST ASSESSMENT
What % carotid stenosis is abnormal?
>50%
Carotid endarterectomy considered if stenosis:
- >70% according to ECST criteria (*European Carotid Surgery Trialists’ Collaborative Group)
- >50% according to NASCET criteria
How was risk of stroke following TIA previously assessed ?
ABCD2 - score >4 indicates high risk of early stroke, >6 predicts stroke (8.1% in 2 days, 35% in week). No longer recommended by NICE.
What is the immediate management of TIA?
300mg aspirin - loading dose (x3 reduced risk of recurrent stroke)
- +/- PPI
- OR clopidogrel if aspirin allergic
Refer for specialist assessment within 24hrs + arrange for MRI (on the day of specialist assessment if possible)
What is the management of TIA after specialist review?
Switch aspirin to clopidogrel once TIA confirmed- aspirin + dipyridamole should be given to patients who cannot tolerate clopidogrel
Control cardiovascular risk factors:
- Optimize: bp (cautiously lower; aim for <140/85mmHg)
- Hyperlipidaemia if present
- DM if present
- AF - anticoagulate with LMWH or direct thrombin inhibitor (dabigartran) or Xa inhibitor/DOAC (apixaban)
- Help to stop smoking.
Carotid endarterectomy if >50% of >70% stenosis according to NASCET and ECST respectively
- Do not stop aspirin preop
Advise not to drive for 1 month
