transient ischaemic attacks in east lancashire 21 november 2012 dr arun kumar singh consultant...

Transient Ischaemic Attacks

in East Lancashire

21 November 2012

Dr Arun Kumar SinghConsultant Physician East Lancashire Hospital NHS Trust

Transient ischaemic attack (TIA)A clinical syndrome characterized by an acute loss of focal cerebral or monocular function with symptoms lasting less than 24 hours and which is thought to be due to inadequate cerebral or ocular blood supply as a result of low blood flow, arterial thrombosis or embolism associated with diseases of the arteries, heart or blood.

Hankey & Warlow 1994

TIA = “brain attack” =

“Mini stroke”

Definition as for stroke except lasts < 24 hours (and not fatal)

Vast majority are ischaemic

TIA: Background About 70 000 transient ischaemic attacks (TIAs) are

diagnosed every year in the in the UK with an overall incidence approaching that of ischaemic stroke

Patients with TIA are generally unstable

However, most patients with TIA will have a benign short-term course

Identification of those at highest and lowest risk of stroke would allow appropriate use of costly secondary prevention strategies, including hospital admission

5% - subarachnoid haemorrhage

15% - intracerebral haemorrhage

80% - ischaemic stroke

Pathology of TIA/stroke

Atherothromboembolism50%




Atherothromboembolism50%






Lenticulostriate arteries arising from the trunk of the middle cerebral artery

Intracranial small vessel disease

25%




Pathology of stroke

Intracranial small vessel disease

25%

Lacunar infarction

Prognostic Indicators

The ABCD2 Score

Age > 60 years 1 point

BP (sys >=140 or dias >=90 1 point

Clinical features of TIA Unilateral weakness or… 2

points Speech impairment without weakness 1 point

Duration > 60 minutes 2 points 10 – 59 minutes 1 point

Diabetes Mellitus 1 point

Score Range 0 - 7

Use of ABCD2 score

Does not replace clinical diagnostic skill or acumen

This has be incorporated into new local TIA guidelines for investigation or fast-track out-patient referral

A score of 4 or more in a patient with a clinical TIA will likely trigger referral for seeing patient within 24 hrs

Use of ABCD2 scoreTIA patient

After 72 hoursSingle Event

Within 72 hoursAfter 72 hours but>1 Event in 1 week

ABCD2

score

0-3

Weekly TIA clinic

4-7

ImmediateTelephone RBH

page Stroke coordinator

TIA SERVICE IN ELHT

7 Days service On Weekends only high risk TIA seen

Only 1 Doppler slot

REFERRAL TO TIA SERVICE Ring RBH switchboard and page 387 (Stroke

coordinator) Have Patient present with you Anyone with ABCD2 score of 4 or more will be

given appointment on the same day or next day as you ring

All other referrals will be seen within a 7 days period

Ensure patient understands this is an emergency clinic – may have to wait

Numbers not capped

Patients’ Journey TIA or non stroke pathology decided in clinic

TIA○ Carotid Doppler if appropriate ○ Anti-platelet ○ Cholesterol Management○ BP management○ Cardiac Investigations ○ Driving advice○ Lifestyle advice by Stroke nurse

NICE guidelines: Rapid recognition of symptoms and diagnosis

In people with sudden onset of neurological symptoms a validated tool, such as FAST, should be used outside hospital to screen for a diagnosis of stroke or TIA

In people with sudden onset of neurological symptoms, hypoglycaemia should be excluded as the cause of these symptoms

Assessment – High Risk People who have had a suspected TIA who are at

high risk of stroke (that is, with an ABCD2 score of 4 or above) should have aspirin (300 mg daily) started immediately specialist assessment and investigation within 24 hours of

onset of symptoms measures for secondary prevention introduced as soon as

the diagnosis is confirmed, including discussion of individual risk factors

People with crescendo TIA (two or more TIAs in a week) should be treated as being at high risk of stroke, even though they may have an ABCD2 score of 3 or below

Assessment - low risk If risk of stroke low (i.e. an ABCD2 score of 3 or

below) should have: aspirin (300 mg daily) started immediately specialist assessment and investigation as soon as

possible, but definitely within 1 week of onset of symptoms

measures for secondary prevention introduced as soon as the diagnosis is confirmed, including discussion of individual risk factors

People who have had a TIA but who present late (more than 1 week after their last symptom has resolved) should be treated as though they are at lower risk of stroke

Suspected TIA – referral for urgent brain imaging

TIA who are at high risk of stroke (vascular territory or pathology is uncertain) should undergo urgent brain imaging (preferably diffusion-weighted MRI [magnetic resonance imaging])

TIA who are at lower risk of stroke (vascular territory or pathology is uncertain) should undergo brain imaging (preferably diffusion-weighted MRI)

Diffusion-weighted MRI is the investigation of choice except where contraindicated in which case CT (computed tomography) scanning should be used

MRI SCAN

Duration of attack and percentage of patients with a relevant infarct on CT

0

5

10

15

20

25

30

35

40

45

50

% of patients withinfarct on CT scan

1-30

min

31-6

0min

1-4

hour

s

5-24

hou

rs

1-7

days

1-6

wee

ks

Per

sist

ing

Duration of symptoms

Koudstaal et al 1992 JNNP;55:95

Warfarin-Aspirin Recurrent Stroke Study (WARSS) Trial

Is Warfarin Really a Reasonable Therapeutic Alternative to Aspirin for Preventing Recurrent Noncardioembolic Ischemic Stroke?Warfarin Is Equally Effective as Aspirin

As warfarin is used secondary to a cause (AF, DVT, Metal valve etc) there is no need to stop warfarin

This is different if patient has a stroke

AMAUROSIS FUGAX

…and the role of

Carotid Endarterectomy

Definition Unilateral transient loss of vision. This may

be partial or complete, related to retinal arterial microembolization or hypoperfusion.

It is mostly painless Described as fleeting darkness or blindness

Retinal transient ischemic attack (RTIA)Transient monocular blindness (TMB)

Accounts for 25% of anterior circulation transient ischemic attacks (TIAs).

Amaurosis Fugax..

Amaurosis fugax is a symptom of carotid artery diseases

It occurs when a piece of plaque in a carotid artery breaks off and travels to the retinal artery in the eye

Etiologies:Transient visual loss

Occlusive retinal artery diseaseAtheroembolic, cardioembolic, arteritic,

hematological disorders, congenital, orbital tumor

Low retinal artery pressureOcular ischemia syndrome, arteriovenous fistula,

congestive heart failure, anemia

Optic disc disease and anomaliesPapilloedema, Glaucoma, Drusen

Vasospasm (ophthalmic migraine) Miscellaneous

Uhthoff’s phenomenon, classic migraine

Conclusions

Amaurosis Fugax is caused by ischemia to the retina, often associated with carotid stenosis, and is a risk factor for stroke

Prognosis is better for patients with amaurosis fugax treated both medically and surgically compared to patients with hemispheric TIAs

Amaurosis Fugax should be recognized, with strong consideration for carotid endarterectomy with high grade carotid stenosis, vascular risk factors present, and low complication rate of procedure in your centre

Driving advice: Updated: May 2012

Group 1 entitlement ODL – car, motorcycle

TIA No need to notify DVLA, must not drive for 1 month

Driving Advice- Group 2 entitlement vocational – lorries, busesLicence refused or revoked for 1 year.

○ Can be considered for licensing after 1 year○ No debarring residual impairment likely to

affect safe driving○ No other significant risk factors.

(This is subject to satisfactory medical reports including exercise ECG testing)

Imaging evidence of less than 50% carotid artery stenosis no previous history of cardiovascular disease

(Group 2 licensing may be allowed without the need for functional cardiac assessment

However, if there are recurrent TIAs or strokes functional cardiac testing shall still be required

Key points TIA is a medical emergency There is no diagnostic test for TIA Diagnosis can be very difficult or relatively easy Diagnosis rests almost entirely on the history,

balance of risk factors and selected targeted investigations Attacks occur suddenly, are maximal in severity

within seconds-minute, affect all areas simultaneously

Loss of consciousness is EXCEEDINGLY uncommon

Isolated Dizziness or diplopia is EXCEEDINGLY uncommon

Peripheral pain is very UNUSUAL Headache is not unusual (15-20%)

Key points…

Prescribe ASPIRIN 300mg stat then 75mg Clopidogrel regularly

Fax referral to TIA clinic Patients with > 1 TIA in 1/52 or high ABCD2

score >5 should be investigated in hospital

ALWAYS ADVISE ON DRIVING

transient ischaemic attacks in east lancashire 21 november 2012 dr arun kumar singh consultant...

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