Transient ischaemic attack (TIA) investigation and management in the emergency department

1. TIA – The questions
Jim Fleet

2. Introduction
• Common encountered diagnosis and
very common differential
• Often initial presentation to A&E
– Or GP ushered
• Fairly rapidly evolving evidence base
• Still many unanswered questions
• Variable approach to
management/service provision

3. Topics
• Stroke and TIA diagnosis
• Risk assessment
• Service provision and investigation
• Secondary prevention

4. Case - Mr O
• 37 year old man
• PMH:
– Marfan’s syndrome
– Ulcerative colitis
• Presents with:
– Episode of memory loss 2/52 ago
• Could recall simple instructions at work
– Headache of gradual onset 3/7, more
prominent on left, intermittent
– 3-4 episodes of right arm weakness and
numbness
• Lasting 15 minutes
– 2 episodes of buttock numbness

5. Mr O
• Normal neurological examination
• Normal cardiovascular exam (BP
128/84)
• ECG – SR
• CTB ....
• What to do??

6. First question - Is it a stroke/TIA?
• Most important questions across
spectrum on acuity
• What are the common mimics and how
can you find them?
• Sudden onset
• Worse within minutes of onset
Hand , 2006

7. Collapse and TIA
• Consciousness disturbance indicates
pathology of reticular activating system
• Diffuse pathway – requires significant
vascular insult
– Likely to have focal deficits and CT changes
within hours if anterior
– Unlikely to recover rapidly – “never” a TIA
• Diagnosis – Syncope, seizure,
hypoglycaemia
• Pitfalls
– Focal neurology in seizure & hypoglycaemia
– Thalamic syndromes and secondary delirium
• Still likely to have subtle focal neurology in
neurologically robust patients

8. He’s vertiginous – it is a stroke
• Need to distinguish peripheral vs central
– Peripheral usually benign - no A&E
neuroimaging required
– Central - needs admission for MRI
• Key is examination if ongoing symptoms
– Focal neurology
– Nystagmus
• Central is multi-directional or up beating
• Peripheral is uni-directional and horizontal
– Eye ROM including skew test
– VOR – the head thrust test
– Application of these principles sensitivity
similar to MRI (HINTS study, Kattah, 2009)
• Other “red flags” - Headache & hearing
loss
• TIA very tricky!

9. Head thrust test

10. Confusion
• Receptive dysphasia
– Can come in under the stroke radar
– Paraphasic errors and neologisms
– Attention key
• Transient global amnesia
– Profound but isolated inability to form
new memories
– loss of self-awareness and intact
higher functions excludes TGA
– Prominent perseveration
– Lasts less than 24 hours

11. Delirium
• Fluctuations in over time
• Attention is the key!
• Can be very difficult differential in a person
with an aged or demented brain
• Stroke diagnosis principles apply as delirium
complicates stroke in the aging brain
– As above - onset, focal deficits, vascular
territory
• Other acute medical condition
• Consider chronic medical condition prone to
delirium e.g. Decompensated cirrhosis

12. Functional
• Examination key here
– Gait
– Hoover’s sign
– Pronator drift
– Distraction & variability
– Give way weakness
• Beware of overlay and resolved
transient phenomenon
• Difficult to interpret psychological co-
morbidity

13. Migraine
• Headache often occurs after onset of
neurology
• Spotted by
• Gradual spreading of symptoms over
vascular territories
• Positive symptoms
– Scintilating scotoma
• Flashing lights
• Zigzagging
• Haze
– Strange sensory abnormalities - water
flowing down skin, paraesthesia still can be
stroke
• Hemiplegic migraine rare in onset over

14. Vision deficit
• Common presentation
• Transient painless visual loss is a stroke
case
– Most people don’t check if one or both eyes
involved
• Ophthalmology review however very
useful
– Retinal detachment/tear, venous occlusion
– Stroke aetiology
• Visualising an embolus very helpful
• ? Roth spots
• Similar stroke work up
– Less high risk however

15. TIA
• High risk of subsequent stroke
– Likely higher than completed stroke using
traditional definitions
• Witnessed population based success
– Treating TIAs urgently reduces the risk of
stroke by 80% (EXPRESS, 2007)
• In 2004, one in 10 TIAs led to a stroke
within a week in UK
• In 2012, about one in 20 TIAs led to a
stroke within a week

16. I think he’s had a TIA – what now?
• Do I need a scan in A&E?
– CT helpful
– Silent ischaemia
– Approx 1% in people will have non-
ischaemic scan
• Convexity SAH, SDH
• Tumour
• Scan the amaurosis?

17. MRI in TIA
• Acute MRI most helpful in clarifying
difficult cases
– 50% of traditional thought of TIA have DWI
abnormality
– Risk stratification significantly improved
– More common internationally
– Resultant tissue based definition
– Future: MRI perfusion

18. Other investigations
• Time critical (EXPRESS, 2007; SOS-TIA, 2007)
– Investigation to identify modifiable risk
factors
– Rapid initiation of stroke secondary
prevention
• Investigations
– Vascular anatomy
• Dopplers
– Early endarterectomy effective (NNT=6
at 2 years)
• CTA/MRA
– Dissections esp. young people
– Posterior circulation – high risk if
stenosis

19. Investigations
• Cardiac work up
– Up to ¼ have indication for anticoagulation
(broadly)
– ECG mandatory (and easy)
– Further telemetry/holter helpful
– Echocardiogram needed in most patients

20. In patient vs outpatient management?
• Risk stratification plays a (health
economic) role
• ABCD2
– use your app!
• Often quoted that if > 4 should be
admitted
Score 2 day stroke
risk
7 day stroke
risk
1-3 (low) 1.0% 1.2%
4-5 (moderate) 4.1% 5.9%
6–7 (high) 8.1% 11.7%

21. ABCD2
• Developed for 10
care
• External validation inconsistent
• Poorly performing in
– Hospitals (high risk group)
– Vs Specialist assessment
• Probably very difficult to simplify to
simple risk model
• Possible mimic exclusion?
• Possible role of diagnostics/treatments in
hospital

22. Other risk features
– Known carotid disease
– Multiple/fluctuating course
• Capsular warning syndrome
• Possible artery-artery embolism
– AF (?)
• Traditional thought of as high risk
population
– DWI hits
• Practical relevance
• May be even higher than traditional
defined stroke
– ? Related to sub-type e.g. artery to artery
– Needs more work

23. Service provision
• Risk front loaded
– Traditionally 50% of 30 day stroke risk
in 1st 24 hours
• Imaging revealing increasing
recognised dynamic process
• New stroke or evolution
• Collaterals & spontaneous re-
canalisation
– Is this relevant to clinical practice?

24. Service provision – who to admit?
• Where should rapid diagnostic work up be
done?
– A&E
– Clinic
– Inpatient
– GP
• Who should get admitted for monitoring
– Potential deterioration - who?
—High risk groups – how to identify?
—Hyper-acute treatment – is it cost effective?
—Investigations - telemetry
—At risk if alone

25. Medical management - Antiplatelets
• Dipyridamole out
– Bd dosing + side effects
• Aspirin
– Largest evidence base (CAST + IST)
– Stroke prevention - NNT = 111 in first 2
weeks
– Combined cardiovascular outcomes NNT 25-
30 over 2 years
– Various doses used (300mg in CAST)
• Clopidogrel
– Better than aspirin (but NNT=200) (CAPRIE, 1996)
– Not tested in TIA or acute stroke
monotherapy

26. Antiplatelets
• Combination
– In conventional stroke
• Worse outcomes (MATCH trial, 2004; SPS3 2011
CHARISMA, 2006)
– In high risk TIA or smaller stroke (CHANCE,
2013)
• 28 days combination
• 90 recurrent stroke 3.5% ARR
• Chinese population
• A/W subgroups analysis
– Non-clinical data supporting (CARESS, 2005;
CLAIR, 2010)

27. Antiplatelets
• Future
– Combination therapy in non-asian
populations (POINT)
– Different subgroups
–Large artery atherosclerosis
– Triple therapy (TARDIS)
– More potent anti-platelets

28. Anticoagulation
• Heparin higher risk of death than
aspirin in acute ischaemic stroke (Berge,
2002)
• However – certain subtypes may be
beneficial
– Cardiac mural thrombus
– Intra-arterial thrombus?
• Note aspirin as effective as warfarin
(WARSS, 2002)
• May not need aspirin in addition if another
anticoagulation requirement

29. Lipids
• Atorvastatin 80mg tested in stroke
group in SPARCL trial
– 1 to 6 months after stroke
– Combined ARR over 5 years was 3.5%
– Similar RRR whatever baseline LDL-
cholesterol
• Start low as SE occur
• Simvastatin?
• Fibrates or ezetimibe?
• Targets?

30. Blood pressure
• Most important secondary prevention option
• Often transiently elevated in acute stroke
– ? TIA
• However little acute trial data
• Influenced most by PROGRESS trial
– Perindopril/indapamide
– Similar RRR across very broad BP range
• Goal is 130/80
• Start in A&E ?

31. Mr O
• Discharged on aspirin
• Urgent OPD MRI

32. Mr O
• Readmitted, symptoms settled with
aspirin
• Readmitted again 2 months later with
recurrent symptoms
– Anticoagulated
• Due for follow up neuro-imaging in few
months

33. Thanks!!