What is a stroke?A stroke occurs when an artery supplying the brain

either blocks or bursts

Definition of a stroke

• Sudden onset

• Focal neurological disturbance e.g. speech problem, limb weakness

• Vascular in origin (i.e. blood clot or bleed)

• Symptoms last more than 24 hours

• Definition includes subarachnoid haemorrhage (bleeding which occurs from a small swelling in blood vessel in the brain) which presents with severe headache with or without focal neurology.

Definition of Transient Ischaemic Attack (TIA)

• Sudden onset • Focal neurological disturbance• Assumed to be vascular in origin• Lasts <24 hours

• Symptoms improve because blocked blood vessel spontaneously unblocks and blood supply returns

How common is a stroke?

• 3rd most common cause of death

• Commonest cause of disability; 50% survivors disabled at 6 months

• 120,000 strokes per year in UK

• 15,000 strokes per year in Scotland

• Approx. 700 hospital admissions per year in Edinburgh

• 2.3 million deaths due to stroke per year in U.S

3rd Most Common Cause of Death

Cortex

(movement, sensation, intellect, language etc)

Cerebellum

(balance and control of movement)

Brain stem

(controls breathing, blood pressure, sleep

etc)

Symptoms Depend on part of Brain Affected

Neurological effects of stroke (and TIA) • Weakness down one side of body (opposite side of brain)

• Poor balance

• Sensory symptoms (e.g. numbness)

• Speech problems: language (usually dominant i.e. left side of brain) (affects both production of language and understanding)

• Speech: articulation • Swallowing problems

• Visual problems (e.g. double vision, loss of visual field) • Dyspraxia (difficulty with complex tasks)

• Perceptual problems e.g. neglect• Memory and thinking

• Incontinence

Symptoms Depend on part of Brain Affected

Is it a Stroke or not? • Other medical conditions can ‘mimic’ a stroke (brain

tumour, seizure, migraine, low blood sugar, infection) • About a fifth of patients with suspected stroke turn

out not to have had a stroke

• Brain scans essential to exclude stroke ‘mimics’

• Two main types of brain scans: CT and MR

• CT is the most accessible type of imaging. MR less widely available

Two Main Types of Stroke

• Haemorrhage (due to bleeding into the brain): cause about 15% of strokes

• Ischaemic (due to a blocked blood vessel): cause about 80% of strokes

CT Scan of a Patient with a Haemorrhagic Stroke

Fresh blood shows up as a white ‘blob’

http://www.strokecenter.org/radiology/browser.aspx, case #14832

Examples of Scans - Ischaemic Stroke

Oxfordshire Community Stroke Project Classification for: Haemorrhagic and Ischaemic Stroke

TACS • Visual field loss• Weakness arm or leg• Dysphasia or inattention

or dyspraxia

PACS • Only two of the three

symptoms of TACS

LACS • Weakness or sensory

loss• No other symptoms

POCS • (brain stem or cerebella

symptoms)

Total Anterior Circulation Syndrome (TACS)

• 60 year old lady• Found on floor by husband • Right sided weakness (no movement in arm, slight

movement leg)• Looking to left and ‘ignoring’ right side • Right facial droop • Right visual field loss • Drowsy• No speech and not following commands • Sounded ‘chesty’

Partial anterior circulation syndrome

(PACS)

• 80 year old man• Sudden onset right hand weakness whilst drinking a

cup of tea, spilt tea

• Difficulty finding the ‘right words’• Able to understand people• Vision fine, leg fine

• Symptoms improved over 48 hours, only mild right hand weakness remained

Typical stroke (Lacunar Syndrome)

• 58 year old lady

• Walking down the road

• Suddenly noted tingling in right arm and then some weakness in right arm and leg

• Speech was normal

• 5 years ago had had a similar episode on left side of body

Typical Stroke (Posterior Circulation Syndrome)

• 65 year old man• Sitting in a chair• Suddenly room starting spinning• Tried to get up, felt like he was ‘drunk’ and fell over• Double vision• Vomited

Referral for exercise:

Classification of Patients (data from STARTER)

0

5

10

15

20

25

30

35

TACS PACS LACS POCS

number

Possible descriptions of stroke when patients referred for exercise

Pathological subtype• Ischaemic, infarction

• Description of likely cause e.g. embolic

• Haemorrhagic, ‘intracerebral haemorrhage’, ‘ICH’, ‘PICH’

Classification• Oxfordshire Community

classification• Site of lesion on brain

scan– Middle cerebral

artery territory, posterior cerebral artery territory

Risk Factors for Ischaemic Stroke Common • Hypertension• Diabetes mellitus• Cigarette smoking• Atrial fibrillation• Carotid stenosis• Cardiac disease• Alcohol• High cholesterol• Obesity• Reduced physical activity• Diet

Rarer • Vasculitis• Polycythaemia• Leukaemia• Hyperviscosity• Thrombophilias• Anti-phospholipid

syndrome• Neurosyphilis• Endocarditis

Risk Factors and Causes of Haemorrhage

Primary Intracerebral Haemorrhage• Hypertension• Coagulation disorder• Aneurysm• Arterio-venous malformation (AVM)• Cigarette smoking• Amyloid angiopathy• Drug abuse

Causes of Ischaemic Stroke

• Blood clot forms in artery in brain e.g. middle cerebral, or small deep artery in brain

• Blood clot forms at another site and ‘travels’ to brain (embolism)– Aorta (main artery in chest)– Carotid artery (in neck)– Heart

Left Atrial Thrombus

http://content.nejm.org/cgi/content/full/328/11/771/F1

Blood Tests for Stroke • Blood glucose (for diabetes and low sugar)• Cholesterol• Full blood count

– Anaemia (low haemoglobin) or polycythemia (too many red cells)

– White cells (? Infection)– Platelets (? Too many or too few)

• Electrolytes (e.g. sodium and potassium)• Urea and creatinine (kidney function and hydration)• ESR (for inflammation)• Blood clotting (for haemorrhagic stroke)

Other tests

• Chest X-ray (heart size, lungs)

• Electrocardiogram (ECG)

• Some patients may have carotid Dopplers (to look for narrowing of carotid artery)

• Some patients may have echocardiography (i.e. ultrasound of the heart) to look for blood clot in heart and abnormalities of the heart valves)

Electrocardiogram (shows electrical rhythm of heart)

Echocardiography (left ventricular thrombus)

http://content.nejm.org/cgi/content/full/346/18/e5

Colour duplex Doppler from tight internal carotid stenosis

Summary

• Stroke is 3rd most common cause of death

• Most common cause of disability• 85% are Ischaemic (blocked artery)• Symptoms depend on part of brain affected

• Oxfordshire Community Stroke Project Classification in widespread use

• Different causes and risk factors for stroke