TIA / Stroke

Question 1

In general what happens in a TIA and stroke?

Why does TIA need to be recognised early?

Answer 1

• TIA and stroke are a spectrum of disease involving brain ischaemia
• prompt diagnosis of TIA leads to early start of treatment which can prevent a disabling stroke / death

Question 2

What is the definition of a transient ischaemic attack (TIA)?

What 4 features must be present for it to be classed as a TIA?

Answer 2

• temporary state of reduced blood flow causing reversible neurological deficit
  
  • this could be arm weakness, speech deficit, etc. but it reverses on its own
• onset is always sudden
  
  • ​if the onset is gradual, then this is NOT a TIA
• duration normally from 10 - 60 minutes
• resolves within 24 hours

Question 3

What is the newer definition of TIA that involves all patients being imaged with MRI?

Answer 3

• a transient episode of neurological dysfunction caused by focal brain or retinal ischaemia without acute infarction on imaging
• if an infarction is present on MRI, this is a stroke and not a TIA

Question 4

How is TIA diagnosed?

Answer 4

• diagnosis of TIA is based on taking a good history
  
  • all 4 features of TIA should be present:
  • sudden onset
  • resolves by itself within 24 hours
  • usually lasts for 10-60 minutes
• an MRI can be used to distinguish between a TIA and a stroke
  
  • ​if there is an infarct, this is a stroke

Question 5

Who should not be referred to a TIA clinic?

Answer 5

• patients who have gradual onset of symptoms
• patients with generalised weakness in all 4 limbs
• funny turns, dizzy spells or collapse/loss of consciousness without focal neurological signs / symptoms

Question 6

What is meant by focal neurological signs / deficits?

Answer 6

• impairments of nerve, spinal cord or brain function that affects a specific region of the body
• e.g. weakness in the left arm, paresis or plegia

Question 7

What is the ABCD² score used to determine?

Answer 7

• this is an indicator of the risk of a patient having a major / disabling stroke in the days and weeks following a TIA
• this is performed prior to a patient being seen at a TIA clinic to determine whether they are low or high risk

Question 8

How is the ABCD² score calculated?

Answer 8

• A - Age
  
  • anyone 60 or older scores 1 point
• B - Blood pressure
  
  • ​BP =/> 140/90 scores 1 point
• C - Clinical features
  
  • ​unilateral weakness scores 2 points
  • speech disturbance without weakness scores 1 point
  • unilateral weakness AND speech disturbance scores 3 points
• D - Duration of symptoms
  
  • ​if between 10 - 59 mins then scores 1 point
  • if 60 mins or longer then scores 2 points
• D - Diabetes
  
  • ​if patient has diabetes then this scores 1 point

Question 9

How is the ABCD² score used to determine if a patient is high risk or not?

What should be done with these patients?

Answer 9

• ABCD² score of 4 or more or someone with crescendo TIAs should be seen within 24 hours
• ABCD² score below 4 or amaurosis fugax are low risk TIAs and need to be seen within 1 week

Question 10

What is meant by crescendo TIAs?

Answer 10

• this involves having 2 or more episodes** of TIA **within 24 hours, with complete resolution each time

Question 11

What is meant by amaurosis fugax?

Answer 11

• this is retinal ischaemia due to a clot in the retinal artery
• it usually presents with sudden blindness in one eye, like a curtain dropping down and then suddenly being lifted
• it is temporary and is caused by a lack of blood flow to the retina

Question 12

What is the risk of stroke in a patient scoring 4 or more on the ABCD² score?

When is risk highest?

Answer 12

• 7 day risk of stroke following TIA can exceed 30% in patients scoring ABCD² of 4 or more
• risk is highest in the first 48 hours following TIA

Question 13

What type of advice is given to patients following a TIA?

Answer 13

• lifestyle changes
• cannot drive for 4 weeks following TIA
• cannot travel unless informed insurance about recent TIA
• need to warn patient that if they have any further events, ring 999 or go straight to A&E

Question 14

What are the risk factors for stroke / TIA?

Answer 14

• age > 65 years
• smoking
  
  • this is the single biggest risk factor for stroke / TIA
• hypertension
• diabetes
• hypercholesterolaemia
• atrial fibrillation
  
  • if not anticoagulated, risk of stroke is increased by 6 times
• previous TIA
• ischaemic heart disease / peripheral vascular disease
• migraine

Question 15

What are the typical findings on neurological examination in TIA?

Answer 15

• neurological examination should be normal as symptoms should have resolved by the time the patient is seen
• if neurological symptoms are present, this is a stroke !!

Question 16

What routine blood tests are performed in TIA?

Answer 16

• FBC
  
  • if patient has polycythaemia (high Hb) they have more viscous, thick blood that is more prone to forming clots
• U&Es
  
  • ​need to know renal function before starting ACEi
• LFTs
  
  • ​want to know baseline liver function as statins can affect the liver
• ESR
• HbA1c
  
  • ​to check if the patient is diabetic
• TFTs
• FLP - fasting lipid profile

Question 17

What other investigations might be performed following TIA?

Answer 17

• ECG to look for atrial fibrillation
• carotid USS to look for stenosis or dissection
  
  • stenosis tends to affect older patients
  • dissection tends to affect younger patients (<50)
• CT head in crescendo TIA or minor stroke
• MRI in crescendo TIA or cerebellar TIA
• In younger patients then a thrombophilia screen, autoantibody screen and echo with contrast are done
  
  • Echo will look for patent foramen ovale

Question 18

What is involved in the management of TIA?

Answer 18

• lifestyle changes
  
  • avoiding red meat
  • taking up swimming / gentle exercise
  • smoking cessation
  • weight loss
• antiplatelets - preferably clopidogrel
• statins - preferably atorvastatin
• ACEi / ARB / CCB if patient has hypertension
• anticoagulants if patient has AF - after calculating CHAD VASc score
  
  • ​they are offered the choice of warfarin or a DOAC/NOAC such as apixaban, rivaroxaban or dabigatran

Question 19

What are the benefits to choosing warfarin over a DOAC?

What are the benefits of choosing a DOAC over warfarin?

Answer 19

• warfarin has a very narrow therapeutic window so INR needs to be checked regularly
  
  • INR < 2 - blood is too thick and embolic event is likely
  • INR > 3 - blood is too thin and bleed is likely
• DOACs do not require blood tests
• warfarin has an antidote - vitamin K can be given to stop bleeding if INR is too high
  
  • only dabigatran currently has an antidote

Question 20

What is a carotid endarterectomy (CEA)?

When is this performed?

Answer 20

• this involves opening up a blocked carotid artery in carotid stenosis
• it is performed when a patient has significant stenosis on the symptomatic side
  
  • significant stenosis is stenosis of > 50%
• if someone has right arm / leg weakness, the left carotid is the symptomatic side
  
  • ​the left carotid artery supplies blood to the left brain, which supplies the right side of the body

Question 21

When is an urgent scan of the head required for suspected TIA?

Answer 21

• prior to thrombolysis treatment
• in severe headache when subarachnoid haemorrhage (SAH) is suspected
• when GCS < 13
• when patient is on any form of anticoagulants
• if symptoms are progressive / patient is having falls
• neck stiffness / pyrexia / papilloedema due to suspected meningitis
• (all other patients with suspected TIA are scanned within 24 hours)*

Question 22

What are the 2 different causes of stroke?

Answer 22

• 80% are due to infarction as a result of a thrombus forming within a blood vessel and restricting blood flow to the brain
• 20% are due to intracerebral haemorrhage

Question 23

What are the treatments for stroke due to infarction (blood clot)?

Answer 23

• ideal treatment is embolectomy
  
  • this involves going through the femoral artery and into the middle cerebral artery to remove the thrombus
  • not many hospitals offer this
• second line treatment is thrombolysis
  
  • ​this involves chemically dissolving the clot with alteplase
• if above 2 are not possible then antiplatelets are given
  
  • ​this is 300mg aspirin orally / rectally or NG

Question 24

What medications / interventions are implicated in the secondary prevention of stroke / TIA?

Answer 24

• statins
• antiplatelets
• antihypertensives
• diabetic control
• anticoagulation
• carotid intervention (if stenosis is present)

Question 25

What is involved in management of stroke due to intracerebral haemorrhage?

Answer 25

• if patient is on warfarin then give 10mg IV vitamin K
• octoplex and beriplex
• platelet transfusion is given if there is haemorrhage occurring after thrombolysis
• control of hypertension is important - need to keep BP < 160/90

Question 26

What groups may benefit from neurosurgical intervention following stroke?

Answer 26

• age < 60
• GCS more than 12
• lobar haemorrhage that occurs <1 cm from surface of brain
• when volume of blood lost is > 50 mls
• when there is bleeding into the ventricles and intraventricular blood < 5 mls
• cerebellar haemorrhage with brainstem compression and hydrocephalus