Transient ischaemic attacks Flashcards
What is a TIA?
TIA involves a temporary non-functioning of a focal area of the brain due to disruption of the blood flow
What is a TIA typically caused by?
Embolus
What is the pathophysiology behind an embolus causing a TIA?
This disruption is typically caused by an embolus, a dislodged blood clot that can travel in the bloodstream and block cerebral arteries.
The reduced blood flow deprives brain cells of oxygen and nutrients, leading initially to a reversible neurologic deficit.
If blood flow is restored before permanent brain injury occurs, the TIA resolves.
What happens if the blood flow is not restored after a TIA?
ischaemic stroke
What 2 conditions are important to identify as they have a higher rate of early recurrent stroke?
- Atrial Fibrillation
- Carotid Stenosis
What are the risk factors for TIA?
- Increasing Age
- Sex - men slightly higher than women
- Smoking
- Hypertension
- AF
- Diabetes
- Family history
- Prior TIA or stroke
- Vasculitis
What is important to identify a TIA to differentiate them from other disorders?
The most important clinical features to identify are the sudden onset of symptoms and short duration.
The clinical features should appear immediately. The average duration of a TIA is less than 10 minutes.
What are the vague symptoms of TIA?
- Weakness
2, Numbness or tingling - Speech problems
- Vision changes
- Dizziness or loss of balance
- Headache
Name 4 differential diagnoses for TIAs?
- Hypoglycaemia
- Migraine aura
- Seizure
- Syncope
Give 5 presentations associated with TIAs in anterior circulation (carotid system):
- Amaurosis fugax
- Aphasia (trouble speaking)
- Hemiparesis (partial weakness on one side of body)
- Hemisensory loss
- Hemianopia visual loss
What is amaurosis fugax?
sudden loss of vision in one eye caused by optic embolisation (the emboli can be seen on fundoscopy)
Give 5 presentations associated with TIAs in posterior circulation (vetebrobasiular system):
1) diplopia, vertigo and vomiting
2) choking and dysarthria
3) ataxia
4) hemisensory loss
5) hemianopic visual loss
What is diplopia?
Double vision`
What is ataxia?
Loss of coordination of voluntary muscle movements.
What is dysarthria?
Difficulty in speech due to weakness of speech muscles
How are TIAs diagnosed?
based on patient description (it is unusual to witness an attack and TIAs will not produce signs on imaging)
What scoring system is used to assess risk for a TIA patient having a future stroke?
ABCD2
List the ABCD2 scoring system:
1) age (>60: 1 point)
2) blood pressure (>140/>90: 1 point)
3) clinical features (unilateral weakness: 2 points, speech disturbance: 1 point)
4) duration of symptoms (>60 mins: 2 points, 10-59 mins: 1 point)
score of >6 is high risk for a stroke within 7 days of a TIA
How should TIA patients be managed?
all patients with a suspected TIA event should be referred to a TIA clinic and be seen, investigated and managed within 24 hours
Give 3 appropriate investigations for TIAs:
1) Doppler ultrasound of internal carotid arteries
2. ECG
3. MRI/CT/ CT angiography
What is the name given to swollen, non-functional areas surrounding ischaemic stroke sites that remains structurally intact?
ischaemic penumbra (can regain function following revascularisation)
What is the Acute management of fully resolved TIAs?
- 300mg Aspirin
- Refer for assessment
- Screen for AF and carotid stenosis
- If TIA is confirmed and not at high risk of haemorrhage, dual antiplatelets for 21 days (aspirin and clopidogrel)
