2 Ndy r Symposium

7/29/2019 2 Ndy r Symposium

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Slides and explanatory notes

available on

www.dcn.ed.ac.uk/studentnotes


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Aims of todays symposium

What is stroke?

Why is it important?

How can be recognise/diagnose it?How do we investigate it?

How can we localise the brain lesion?

How to distinguish different pathological

types?

How can we treat it?


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Also:

some epidemiological principles

incidence, prevalence, prognosis

simple, clinically relevant neuroanatomy

cerebral localisation

basics of evidence based medicine

randomised trials


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StrokeCerebrovascular Accident (CVA)

Definition

Asyndrome characterised by:

rapidly developingsymptoms and/orsignsoffocalloss ofcerebralfunction

symptoms last more than 24 hours or lead to

death no apparent cause other than a vascular

origin


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Transient Ischaemic Attack (TIA)

A stroke where the symptoms completely

resolve within 24 hours

An arbitrary concept which has some value

in clinical practice and research

may act as a warning

different differential diagnosis to stroke

more difficult to diagnose with certainty

therefore if excluded from stroke makes the

latter a more homogenous group.

Dont bother with other terms e.g. RIND


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Why is stroke important?

It is common

It is often fatal

Many survivors remain disabled It has major cognitive and psychological

effects

It accounts for about 5% of all NHSresources

It has a huge impact on families etc


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Stroke is common

Incidence (no. new cases/unit pop/yr)

about 200/100,000/yr

120,000/yr in UK

Prevalence (no. cases in population at a

single point in time)

about 800/100,000


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Stroke is often fatal

Case fatality is

20% by 30 days

30% by 6 months

3rd most common cause of death (after

coronary heart disease and cancer)

70,000 deaths per year in UK


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The Bath Principle

Prevalence

Incidence

Case fatality


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Other consequences

Impairments

weak limbs, absent speech, loss of vision,

depression

Disabilities

cannot walk, dress, feed themselves etc

Handicapcannot fulfil role in society e.g. breadwinner,

grand parent


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How do we diagnose a stroke?

Listen to the patients story (the history)

where were they?

what were they doing?

what did they first notice wrong?

how did their symptoms progress?


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Common symptoms of Stroke

Focal

weak/clumsy arm, leg

or both(mono/hemi paresis/plegia)

loss of feeling or

sensation

loss of speech

(dysarthria, dysphasia)

loss of balance

General

Headache

Vomiting

h d i d d


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The symptoms and signs depend on

which part of the brain and which

artery is affected


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Blocked blood vessels


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Remember

In stroke

the symptoms come on rapidly

the symptoms depend on which part of the

brain is affected


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The speed of onset influences

ones certainty of diagnosis


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Why do the symptoms come on rapidly?the relationship of blood flow and neuronal function


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Extension Of Infarction


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If the patients story suggests a stroke

Is the patient the sort of person to have had

a stroke?

are they elderly?

have they got vascular disease elsewhere?

angina, heart attacks, bad circulation in the legs

have they got vascular risk factors? High blood pressure, smoking, diabetes, high

cholesterol


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What is a risk factor

Somebody with the characteristic or risk

factor has a greater risk of developing the

disease

The importance of a risk factor is

reflected by:

how common it is in the population

the strength of its association (relative risk)

the absolute risk of the person

It may or may not be on the causal pathway


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Causal Pathways

Atrial Fibrillation

Clots in the atrium

Embolism to the brain

Stroke

Hypertension

Disease of

cerebral vessels


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A typical story

A 75 year old woman wakes up and tries to

get out of bed

She falls over and cant get up She tries to speak to her husband but cannot

find the words

She cannot move her right arm or leg When she arrives at hospital the weakness

has improved a bit.


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A typical story

Her husband tells us:

she has been on treatment for high blood

pressure

she has angina and diabetes

she smoked until recently


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We examine the patient looking for:

signs compatible with focal damage to the

brain - ones search is guided by the history

evidence of underlying vascular problems

irregular pulse, high blood pressure, heart

murmurs, bruits over arteries.

signs of other diseases which may cause strokes


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Having made a diagnosis of a stroke based

on the story and examination we assess our

certainty that we are right. We carry out tests to confirm the diagnosis,

to identify risk factors and to screen for or

diagnose rare causes. The number of tests we do depends on how

able we are to answer the following

questions.


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Important questions to answer when

assessing a patient with a probable stroke How likely is it to be a stroke?

Which part of the brain is affected

What sort of stroke is it?

Ischaemic (blocked blood vessel)

Haemorrhagic (burst blood vessel)

What is the likely cause?

What problems has this caused?


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There are lots of causes of stroke


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Tests (Laboratory Investigations)

Full Blood Count tell us:

how many red cells (erythrocytes)

too many - polycythaemia

too few - anaemia

how many white and type of white cells

might indicate infection, leukaemia

how many platelets (sticky bits which form clot)

too many - thrombocythaemia

too few - thrombocytopenia


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Tests (Laboratory Investigations)

Erythrocyte Sedimentation Rate (ESR)

reflects the fibrinogen level in the blood and

is a non specificindicator of inflammation

Blood glucose will identify

too low (hypoglycaemia)

too high (hyperglycaemia) - diabetes

Cholesterol

Urea & Electrolytes (renal function and

hydration)


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Other tests

Electrocardiogram - ECG

Is the heart rhythm normal (e.g. AF)?

Has the patient had a heart attack?

Is there evidence of prolonged high blood

pressure?

Echocardiogram

Is there a structural abnormality in the heart

which could be a source of embolism to the

brain?


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Brain imaging

Computerised Tomography (CT)

Is there another pathology causing the

symptoms (e.g. brain tumour)?Are there signs of a stroke?

Is the stroke ischaemic or haemorrhagic?

Magnetic resonance imaging


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Computerised Tomography (CT)


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A cortical infarct


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An ischaemic stroke


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An haemorrhagic stroke


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A cerebellar

haemorrhage

withhydrocephalus


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Haemorrhage into an infarct


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Bilateral subdural haematoma


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A brain tumour


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Imaging the blood vessels

Carotid and Vertebral artery Ultrasoundcan show atheroma and occlusions of vessels in

neck

Transcranial Doppler (TCD)can show flow (or lack of flow) in large

intracerebral vessels

Magnetic resonance angiographycan show extra and intra cranial blood vessels

Catheter angiography


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Carotid Duplex


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Carotid Duplex


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Carotid

Angiography


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Stenosis of

the origin of

the InternalCarotid

Artery


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What is stroke?

Why is it important?

How can be recognise/diagnose it?

How do we investigate it?

How can we localise the brain lesion?

How to distinguish different pathological

types?

How can we treat it?


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Also:

some epidemiological principles

incidence, prevalence, prognosis

simple, clinically relevant neuroanatomy

cerebral localisation

basics of evidence based medicine

randomised trials

Documents

2 Ndy r Symposium