Transient ischaemic attack

Question 1

Define transient ischaemic attack

Answer 1

Transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction. There is sudden onset and complete resolution of symptoms and signs.

Transient ischaemic attack (TIA) = rapidly developing focal disturbance of brain function of presumed vascular origin that resolves completely within 24 hours

Question 2

What are the causes of transient ischaemic attack

Answer 2

Carotid disease is by far the most common cause

In situ thrombosis of an intracranial artery or embolism of thrombus as a result of stenosis or unstable atherosclerotic plaque (16%). Either “white” or “red” clot
Cardioembolic events - in response to secondary risk factor such as stasis from impaired ejection or atrial fibrillation (29%)
Small vessel occlusion - microatheromas, fibrinoid necrosis, lipohyalinosis or small penetrating vessels (16%)
Occlusion due to hypercoagulability, dissection, vasculitis, vasospasm or sickle cell (3%
Uncertain (36%)

Question 3

What are the areas of perfusion of the brain (TIA)

Answer 3

The anterior cerebral artery perfuses the frontal lobe and the strip across the top
The middle cerebral artery perfuses the lateral part of the brain
The posterior cerebral artery supplies the occipital lobe and inferior part of the temporal lobe

Question 4

What are the risk factors for transient ischaemic attack

Answer 4

Cardiac disease: AF, Valvular disease, Carotid stenosis, Congestive heart failure
Hypertension
Diabetes mellitus
Smoking
Alcohol-use disorder
Advanced age
Hyperlipidaemia
Patent foramen ovale (PFO)
inactivity
Obesity
Hypercoagulability

Question 5

What are the symptoms and signs of transient ischaemic attack

Answer 5

Unilateral weakness or paralysis, sensory loss
Dysphasia
Ataxia, vertigo, loss of balance
Sudden transient painless loss of vision in one eye (amaurosis fugax) - Embolic from ICA occludes ipsilateral retinal artery → temporary arrest of blood flow → vision loss
Homonymous hemianopia
Diplopia
Aphasia
Cranial nerve defects
Vertigo
Incoordination
Ataxia
Syncope

Absence of +ve symptoms (shaking, scotoma, spasm) – most cerebrovascular ischaemic events have a deficit (negative)
Absence of headache
Absence of seizure prior to neurological deficit (Seizure with post-seizure (Todd’s) paralysis is a common stroke mimic)
No Hx of epilepsy

Question 6

Differentials for transient ischaemic attack

Answer 6

Stroke
Migraine
Epilepsy
Cerebral tumour
Meningitis
Encephalitis

Question 7

What investigations should be done for transient ischaemic attack

Answer 7

ECG
BP

Lipid profile
Glucose (exclude hypo)
Coagulation screen
FBC
LFTs

CXR
Carotid US doppler→ MRI/CT

Question 8

What is the management for transient ischaemic attack

Answer 8

As soon as suspected → aspirin 300mg ± PPI
Risk stratify - CHA2DS2 - VASc HAS BLED ABCD2

Confirmed
- Clopidogrel 75mg, aspirin + dipyridamol
- Statins (atorvo)
- Anticoagulate e.g. LMWH

Confirmed carotid artery stenosis → carotid endarterectomy

+ follow up

Question 9

What is the criteria for carotid endarterectomy

Answer 9

Doppler and MRI or CTA of neck)
Stenosis >50% (NASCET criteria) + <2 weeks of s/s

Question 10

What is the follow up for transient ischaemic attack

Answer 10

<7 days since first TIA = <24 hours specialist review
>7 days since first TIA = <7 days specialist review
>1 TIA (‘crescendo TIA’) or suspected cardioembolic source or severe carotid stenosis or patient is on warfarin/DOAC or patient has a bleeding disorder = admit and investigate

Question 11

What is the prognosis for transient ischaemic attack

Answer 11

There are no residual symptoms from the primary event
The most significant risk is a second event that causes permanent disability
8% will have a stroke during their hospitalisation
>10% seen in A&E will have a stroke in 3 months
Also indicative of underlying cardiac or atherosclerotic disease
5% will be dead 6 months after the event