Imaging in Acute Stroke – the clinical case for change

Dr Jim McilmoyleConsultant in Stroke MedicineBlackpool Victoria Hospital

2 June 2009

Time is brain

Neurons lost Accelerated aging

Per Minute 1.9 million 3.1 weeks

Per Stroke 1200 million 36 years

J. Saver; Stroke 2006;37;263-266

How effective is thrombolysis

NNT to improve the mRS by 1 point = 3NNT to prevent 1 patient being dependent or

dead = 10

NNH with symptomatic deterioration = 16NNH with worse outcome at 3 months = 30

For every 100 patients treated 32 have a better final outcome and 3 a worse outcome.

Arch Neurol. 2004;61:1066-1070

Converting a stroke into a TIA.

Baseline Day 1

National Sentinel Audit of Stroke 2008

59% of stroke patients have brain scanning within 24 hours of stroke98% of patients had a brain scan

21% of patients had scan within 3 hoursApproximately 15% of patients are eligible for thrombolysis – only 1% receive it.

What is the best imaging strategy for acute stroke?

Average cost of a NHS CT in Scotland :-£30 - £90 in normal working hours£55 - £173 out of hours

“Scan all immediately” cost least and achieved most QALYs

Cost of providing CT is less than inpatient care

Wardlaw JM et al, Health Technol Assess 2004;8(1)

Stroke Mimics

SeizuresSepsisSyncopeSomatisation

Rapid Access TIA clinics

Why TIA’s are important

Warning that blood clots are affecting the brain.

40% of strokes are preceded by a TIA

20% risk of stroke within 4 weeks

Half of this risk is within the first 48 hours.

ABCD2 stroke predictor post TIAThe Lancet 2007;369:283-92

Age 60 yrs or older 1

Blood pressure >140/90 mmHg 1

Clinical features Unilateral weaknessSpeech disturbance (no weakness)Other

21

0

Duration 60 min or longer10 – 59 minutes< 10 minutes

210

Diabetes 1

Rapid Access TIA clinics

DiagnosisOne stop shop – carotid doppler +/- MRI DWI scan1 performed at one visitOptimisation of secondary preventionEarly referral for carotid endarterectomy if indicatedAdvice on healthy lifestyle, driving & stroke

1. NICE Guidelines Stroke 2008

TIA mimics

Glioblastomas and other intracranial tumorsHemiplegic migraineFocal seizures caused by AVM, cavernous angioma, tumors and old strokesDemyelinating lesionsTemporal arteritis

NICE Guidelines Stroke 2008

Potentiality

550 deaths avoided annually

1700 more people with full recovery annually

£20 million saved

NAO: Reducing Brain Damage: Faster access to better stroke care - Nov 2005

Clinical trials of iv tPA in stroke

ECASS I – Oct 1995

NINDS – Dec 1995

ECASS II – Oct 1998

SITS-MOST – Jan 2007