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) 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. Previously, symptoms had to last more than 24 hours, but the American Heart Association guidelines (2009) propose that patients with a visible ischaemic event on magnetic resonance imaging are categorised as ischaemic stroke even if event lasts for <24 hours Stroke 2009;40: , Stroke. 2011;42:

Definition of Transient Ischaemic Attack (TIA) It had previously been defined as sudden onset of focal neurological disturbance, assumed to be vascular in origin, and lasting <24 hours However, in 2009, the definition was amended to include magnetic resonance brain imaging criteria –a brief episode of neurological dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction on brain imaging Stroke 2009;40:

How common is a stroke? 3 rd most common cause of death Commonest cause of severe adult disability; 50% survivors disabled at 6 months 120,000 strokes per year in UK A stroke occurs every 5 minutes in the UK ( In USA: about 795,000 suffer a stroke and 140,000 die each year ( stroke/stroke-statistics/)

3 rd Most Common Cause of Death

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) –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 some stroke ‘mimics’ (e.g. Brain tumour) and to differentiate haemorrhagic from ischaemic stroke Two main types of brain scans: Computed tomography (CT) and magnetic resonance (MR) CT is the most accessible type of imaging and is quick to perform. MR now available in most hospitals, but not all patients are able to tolerate it CT is usually the ‘first-line’ brain imaging-it can identify fresh blood very easily and so distinguish ischaemic from haemorrhagic stroke, and it can identify some stroke mimics e.g. brain tumours

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

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)

TOAST classification-which considers aetiology Large-artery atherosclerotic infarction, (extracranial or intracranial) Embolism from a cardiac source Small-vessel disease Other determined cause e.g. dissection, hypercoagulable states, sickle cell disease Infarcts of undetermined cause (Adams et al Stroke. 1993; 24: 35–41)

Referral for exercise: Classification of Patients (data from STARTER)

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

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)

Summary Stroke is 3 rd most common cause of death Most common cause of adult disability 85% are Ischaemic (blocked artery) Symptoms depend on part of brain affected Oxfordshire Community Stroke Project Classification frequently used to categorise patients Different causes and risk factors for stroke