TIA 

• is defined as “rapidly developed clinical signs of focal or global disturbance of cerebral function lasting fewer than 24 hours, with no apparent non-vascular cause”.
• The lifetime risk of stroke is:
  • in 5 for women
  • 1 in 6 for men
• The risk of stroke following TIA is high
  • up to 1 in every 5 patients go on to have a stroke in the first 3 months
  • half the risk within the first few days.
• New evidence demonstrates aggressive, early management can reduce the incidence of stroke by up to 80%
• The traditional definition of TIA involves an arbitrary time cut off of 24 hours, in reality most attacks last approximately 20 minutes.
• Some authorities internationally have called for a revised definition in which the duration of symptoms is 1 hour or less.

History

• Nature – was the deficit of the motor, somatosensory, visual and/or other system?
• Quality – was there a loss of function (e.g. weakness or numbness) or gain of function (e.g. jerking, parasthesia)?
• Anatomical distribution – did the deficit involve the face, arm or leg; or face, arm and leg?
• Onset – was it sudden, stuttering or gradual?
• Evolution – e.g. did the deficit recover, stabilise or progress?

neurological examination

• Visual fields
• Plantars, reflexes and eye movements
• Speech, visual fields, eye movements, facial weakness, limb weakness & plantars
• Cranial nerves and sensory examination

Risk factor assessment and stratification

• ABCD2 – high risk of stroke within the first 7 days of TIA
  • A = AGE

>60 years (1 point)

• B = BLOOD PRESSURE

>140mmHg systolic ± =90mmHg diastolic (1 point)

• C = CLINICAL FEATURES: 

unilateral weakness (2 points)

speech impairment without weakness (1 point)

• D = DURATION

60mins (2 points)

10-59 mins (1 point)

• D = DIABETES (1 point)

• Interpretation: >4 = HIGH risk; <4 = LOW risk2

• high risk patients – Patients with ABCD2 >4
  • Urgent CT brain
  • Carotid duplex ultrasound
  • should be admitted to a stroke unit
  • where specialist assessment can be carried out urgently

• low risk patients – Patients with ABCD2 <4
  • may be managed in the community, by a GP, private specialist or where possible referred to a specialist TIA clinic
  • CT scan and carotid ultrasound (where indicated) as soon as possible (ie. within 48-72 hours)
  • seen within 7-10 days
  • Ideally the sooner the patient is seen and commenced on therapy the lower the risk of subsequent events.

Acute management of TIA

• Treat AF with anticoagulation – after excluding haemorrhage (INR 2.5)
• Minor stroke deficit which is rapidly improving, such is the case with TIA, is a contraindication to intravenous rtPA

Carotid Endarterectomy : Indication

• Carotid stenosis >70% ICA – stenosis in symptomatic TIA or CVA patients -> incidence of death or major CVA = 2-5%
• Carotid stenosis 50-69% ICA – CEA should only be considered where the benefits clearly outweigh potential harms.
• Eligible patients should undergo CEA within 2 weeks
• CEA is not recommended for those with <50% symptomatic stenosis or those with <60% asymptomatic stenosis

Secondary prevention

• Treat hypertension if > 140/90
• Antiplatelet therapy as above
• Blood pressure lowering agents
  • Using an ACE inhibitor alone or with a diuretic
• High potency statin – regardless lipids
• Behaviour change (e.g. smoking, diet, exercise, alcohol consumption)
• Lifescripts program is a national initiative which provides tools for
• TIA should not drive 2 weeks, 4 weeks if commercial

*In the PROGRESS trial, combination therapy with perindopril plus indapamide reduced stroke risk by 43% in hypertensive and non-hypertensive patients with a history of stroke or TIA.

metro GPs – Barriers/Potential solutions

• Unaware of local stroke units and protocols
  • Establish networks with local neurologists and stroke units
  • Direct communication between referring and receiving clinicians is essential to smooth transitions
  • Develop formal bypass or diversion protocols so that individuals who meet inclusion criteria for time-dependant therapy have an opportunity to receive them
• Lack of tools/ resources
  • Become involved in care pathway planning for patients with TIA and stroke
  • Use pre-hospital screening tools such as ABCD2
• Contact the National Stroke Foundation for additional information

rural GPs – Barriers/Potential solutions

• Rural centre – No CT on site
  • Develop internal protocol to transfer patient with suspected TIA to local private hospital with CT capabilities
  • Develop bypass or diversion protocols with local ambulance service
  • Conduct training of ambulance staff for rapid assessment of signs of TIA/stroke and transfer protocols

• No neurologist or experienced technician on site
  • Develop agreements with local private hospitals for CT scan interpretation or reporting
  • Support future training of local staff with CT imaging and interpretation Telehealth protocols

Driving  after Transient ischaemic attack (advisory only)

Private standards

• A person should not drive for at least 2 weeks following a TIA.
• A conditional licence is not required