Diagnosis and management of
TIA and ischaemic stroke in
the acute phase
BMJ 2011
McArthur et al.
University of Glasgow
Background
• Big change in recent years in care of people with
acute ischaemic stroke – both stroke and TIA
now recognised as medical emergencies that
should be treated as urgently as MI.
• Thrombolysis widely adopted
• “Cautious optimism has replaced therapeutic
nihilism” but still an important cause of death
and disability
• An estimated 900,000 stroke survivors in
England, half of whom dependent on others for
care (estimated cost £8bn per year). Number
likely to increase as demographics change
Terminology, classification
• Stroke (cerebrovascular event, brain attack) still
classified as haemorrhagic or ischaemic
• TIA – similar symptoms but last less than 24
hours, but truly “transient” attack, with no
cerebral infarction, only minutes; longer attacks
probably should be considered as stroke, and
terminology likely to change in the future
Oxford classification –
• TACS, PACS, LACS, POCS
• Once confirmed as ischaemic, terminology
changes to e.g. PACI (Partial anterior circulation
infarct).
Pathological process
• Sources of cardiac emboli – AF, mural thrombus,
valve disease large intracerebral arteries (e.g.
MCA)
• Atherosclerotic disease typically affects the
extracranial internal carotid artery, also vertebral
and basilar arteries
• Lacunar infarction – from occlusion of deep
perforating arteries (both anterior and posterior
circulation)
white matter of cerebral
hemispheres and brainstem
Oxford system of stroke
classification
Total anterior circulation stroke
(TACS)
All three of:
• Contralateral motor or sensory
deficit
• Homonymous hemianopia
• Higher cortical dysfunction*
Posterior circulation stroke
(POCS)
Any one of:
• Isolated homonymous
hemianopia
• Brain stem signs
• Cerebellar ataxia
Partial anterior circulation stroke
(PACS)
Two of:
• Contralateral motor or sensory
deficit
• Homonymous hemianopia
• Higher cortical dysfunction
Lacunar stroke (LACS)
Any one of:
• Pure motor deficit
• Pure sensory deficit
• Sensorimotor deficit
*Higher cortical dysfunction includes
dysphasia/visiospatial disturbance.
Is it a stroke?
One study of 350
admissions for suspected
stroke – 30% had nonstroke diagnosis
Tools do help diagnosis –
• FAST (Face Arm Speech
Test) – PPV of 78%
• ROSIER scale – similar
Frequency of common
conditions that mimic stroke
• Seizure 21%
• Sepsis 13%
• Toxic/metabolic 11%
• Space occupying lesion 9%
• Syncope 9%
• Delirium 7%
• Vestibular 7%
• Mononeuropathy 6%
• Functional 6%
• Dementia 4%
• Migraine 3%
• Spinal cord lesion 3%
• Other 3%
Imaging
• Non-contrast CT – still widely used – useful for
excluding haemorrhage and SOL
…but...detection of ischaemia is poor in very early
stages
• Differentiating ischaemia from haemorrhage can
be difficult after several days
• MRI – preferable – much better sensitivity in
detection of early ischaemia (83% vs CT 26%)
TIA
• If ongoing symptoms (even if only mild), treat as possible
stroke and admit urgently
• Overall 7 day risk of stroke = 5.2% (recent systematic
review)
• ABCD2 estimates risk of recurrence at 2 days - useful in
risk stratification and in diagnosis – many centres offer
same day appts for those at highest risk – this should
probably be the aim for all patients with TIA
• NICE & SIGN guidelines recommend aspirin 300mg and
urgent referral, with ABCD2 score >4 seen within 24 hrs
• EXPRESS study got TIA patients seen in Oxford with
“immediate access” – achieved 80% reduction in
recurrent stroke at 90 days (if replicated could mean
10,000 stroke events prevented annually).
What will specialist centres do?
• Confirmation of stroke diagnosis
• Identification of causes
• Timely initiation of evidence based
treatment
– TIA
– Ischaemic stroke
• Aspirin
• Thombolysis
• Surgical intervention
Patients with TIA
Treatments are aimed at
preventing a further event
Confirmed atrial fibrillation or
mural thrombus
anticoagulants
All patients ->
• antiplatelet or anticoagulant
drugs
• lipid lowering therapy
• antihypertensive therapy
• carotid surgery,
• treatment of diabetes
• advice about diet, lifestyle, and
smoking cessation.
A recent focus of research
has been the potential
benefits of early
antiplatelets, statins,
and antihypertensives
(results of EXPRESS
may be down to this).
“acute” prescription of
antihypertensives may
have no clinical benefit,
although results from
current studies
awaited.
Patients with acute ischaemic stroke - Aspirin
• for every 1000 patients treated acutely with aspirin (160300 mg) 13 fewer deaths occurred by the end of followup - systematic review of antiplatelets after ischaemic
stroke (n=43041)
• UK guidelines recommend that patients with acute
ischaemic stroke are prescribed aspirin 300 mg daily for
two weeks, followed by a long term secondary
preventative antiplatelet strategy.
• Aspirin should be withheld for 24 hours after
thrombolysis.
• rectal preparations may be used is swallowing a
problem.
• Use clopidogrel if patients unable to take aspirin
• no evidence to support early anticoagulation as a
treatment for acute ischaemic stroke.
Patients with acute ischaemic stroke –
benefits of early thrombolysis
• Alteplase (rt-PA) is beneficial if given within 4.5 hours of acute
ischaemic stroke.
• Reduces longer term disability but not improved survival or
immediate neurological improvement
• Two recent pooled meta-analyses of the major thrombolysis trials
(n=277521 and n=367022) demonstrated early thrombolysis ->
clear benefit with significantly better outcomes. In the larger analysis
the odds ratios of a favourable outcome with rt-PA were
–
–
–
–
2.55 (95% CI 1.44 to 4.52) for 0-90 minutes,
1.64 (1.12 to 2.4) for 91-180 minutes,
1.34 (1.06 to 1.68) for 181-270 minutes,
1.22 (0.92 to 1.61) for 271-360 minutes
• Trials have reported that mortality rates at three months are
equivalent to placebo.
Patients with acute ischaemic stroke –
problems with early thrombolysis
• Limited time window is a major barrier to its delivery.
• The risk:benefit ratio beyond 4.5 hours has not been fully
established and ongoing clinical trials aim to provide further
evidence.
• Patients older than 80 years were excluded from most of the clinical
trials. Observational data suggest that their risk:benefit ratio is
similar to that of other patients
• Risk of iatrogenic intracerebral haemorrhage after thrombolysis patient selection guidance is designed to minimise this risk.
• Contraindications to thrombolysis an evolving landscape, so refer
anyway
• Provision of a comprehensive thrombolysis service demands
substantial economic investment and infrastructural change – still
considerable geographical disparity in availability and use of rt-PA
Patients with acute ischaemic stroke –
surgical intervention
• “Malignant” swelling of an infarcted cerebral hemisphere
can occur in first few days esp following TACI/PACI
– uncommon
– associated with a very high mortality.
• surgical intervention saves lives and reduces disability in
selected patients <60.
• meta-analysis of three RCTs - surgical craniotomy
NNT=2 to reduce disability.
• But…reducing mortality at the expense of substantial
disability remains a possibility – accurate selection of
patients is vital, more research needed.
Key messages
• Education of patients and their relatives to recognise signs of stroke
and transient ischaemic attack (TIA) is crucial to promote early
presentation to medical services
• TIA and stroke are medical emergencies; refer for urgent specialist
opinion
• Eligibility for acute treatments is constantly evolving, discuss any
patient with possible acute stroke with the local stroke team
• The risk of further cerebrovascular event following TIA is substantial,
immediate, quantifiable, and preventable; do not be reassured by
resolution of symptoms
• Effective treatments for selected stroke patients include: aspirin
within first 48 hours; intravenous thrombolysis; surgical
decompression of cerebral oedema
• A sudden change in consciousness of an acute stroke patient may
indicate a treatable complication and warrants urgent investigation
• Admission to a dedicated stroke unit offers mortality and functional
benefits to all patients with stroke
So...does this review help us?
• What was new to you?
• In what areas do you need to change your
approach or your practice?
• What are you going to share with your
colleagues back at the surgery?