Ischaemic Stroke

• What is Ischaemic Stroke?
• Statistics on Ischaemic Stroke
• Risk Factors for Ischaemic Stroke
• Progression of Ischaemic Stroke
• Symptoms of Ischaemic Stroke
• Clinical Examination of Ischaemic Stroke
• How is Ischaemic Stroke Diagnosed?
• Prognosis of Ischaemic Stroke
• How is Ischaemic Stroke Treated?
• Ischaemic Stroke References
• Drugs/Products Associated with Ischaemic Stroke

What is Ischaemic Stroke?

Statistics on Ischaemic Stroke

In the United States:

• The number of new or recurrent stroke cases is about 700,000 every year.
• On average, a stroke occurs every 45 seconds.
• Stroke is the third leading cause of death, killing about 157,000 people a year.
• Men are at a higher risk than women for stroke.
• In 2003, the stroke death rates per 100,000 population for specific groups were 51.9 for white males, 50.5 for white females, 78.8 for black males and 69.1 for black females.

In Australia:

• Stroke is also the third largest cause of death, and one of the leading causes of disability.
• There are over 48,000 new cases of stroke a year, with a stroke occurring every 11 minutes.
• At the current rate, this figure is predicted to reach 74,000 by the year 2017.
• One third of stroke patients die in the first 12 months.
• More than 50% of strokes occur in people under 75 years old, and 5% are under the age of 45.

In general, ischaemic stroke accounts for around 80% of all strokes, and haemorrhagic stroke makes up about 20%.

Risk Factors for Ischaemic Stroke

Risk factors for ischaemic stroke include:

• Age (the risk doubles with every 10 years)
• High blood pressure
• High cholesterol
• Smoking
• Diabetes mellitus
• Heart disease
• Previous stroke
• Family history of stroke
• Atrial fibrillation (irregular heart rhythm)
• Transient ischaemic attacks (TIA) - warning strokes. Even though the symptoms disappear after a short time, TIAs are strong indicators of a possible major stroke.
• Thrombophilia (conditions that make the blood more prone to clotting, especially in young patients).

General Cardiovascular Disease 10-Year Risk Calculator

This risk assessment tool is based on data from the Framingham Heart Study to estimate 10-year risk for general cardiovascular disease outcomes (coronary death, myocardial infarction, coronary insufficiency, angina, ischaemic stroke, haemorrhagic stroke, transient ischaemic attack, peripheral artery disease, heart failure). This tool is designed to estimate risk in adults aged 30-74 years of age without CVD at baseline examination. Use the calculator below to estimate 10-year risk.

Predictors

Age		years
		Male	Female
Gender
		Yes	No
Have you been diagnosed with Type II diabetes?
Are you a smoker?*
Are you prescribed medication to lower your blood pressure?
If you do not know the following blood pressure and cholesterol parameters ask your General Practitioner on your next visit.
Systolic blood pressure**		mmHg
Total cholesterol***	mmol/L      OR	mg/dl
HDL cholesterol****	mmol/L      OR	mg/dl

Results

Significant (> 20%)
Elevated (10–20%)
Mild risk (< 10%)
You have a significant risk of future cardiovascular disease requiring aggressive risk factor modification. You should see a health professional to ensure appropriate management.

• If diabetic, your sugar levels should be well controlled.
• Continue to avoid tobacco use or if you are a smoker, consider stopping this is something your General Practitioner can help you with.
• Blood pressure should be monitored closely. If elevated you should consider either lifestyle modification or appropriate medication. Your general Practitioner can advise you on this.
• Cholesterol levels should be assessed at least annually. Depending on your level, you might be advised to commence lifestyle changes or medication.

Significant (> 20%)
Elevated (10–20%)
Mild risk (< 10%)
You have an elevated risk of future cardiovascular disease requiring risk factor modification. You should see a health professional to ensure appropriate management.

• If diabetic, you should aim for your sugar levels to be well controlled.
• Continue to avoid tobacco use or if a smoker, consider stopping this is something your general practitioner can help you with.
• Blood pressure should be monitored closely. If elevated you should consider either lifestyle modification or appropriate medication. Your general Practitioner can advise you on this.
• Cholesterol levels should be assessed at least annually. Depending on your level you might be advised to commence lifestyle changes or medication.

Significant (> 20%)
Elevated (10–20%)
Mild risk (< 10%)
You have a mild risk of future cardiovascular disease, consider risk factor modification. You may like to see a health professional to ensure appropriate management.

• If diabetic, you should aim for your sugar levels to be well controlled.
• Continue to avoid tobacco use or if a smoker, consider stopping this is something your general practitioner can help you with.
• Blood pressure should be monitored closely. If elevated you should consider either lifestyle modification or appropriate medication. Your general Practitioner can advise you on this.
• Cholesterol levels should be assessed at least annually. Depending on your level you might be advised to commence lifestyle changes or medication.

^*For these purposes "smoker" means any cigarette smoking in the past month.
^**Use current blood pressure, regardless of whether the person is on antihypertensive therapy.
^***Total cholesterol values should be the average of at least two measurements obtained from lipoprotein analysis.
^****HDL cholesterol values should be the average of at least two measurements obtained from lipoprotein analysis.

References:

1. D'Agostino RB, Vasan RS, Pencina MJ, Wolf PA, Cobain M, Massaro JM, Kannel WB. General cardiovascular risk profile for use in primary care: the Framingham Heart Study. Circulation 2008; 117: 743-753.
2. National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation 2002; 106: 31433421.
3. Stancoven A, McGuire DK. Preventing macrovascular complications in Type 2 Diabetes Mellitus: glucose control and beyond. American Journal of Cardiology 2007; 99: 5H-11H.

Progression of Ischaemic Stroke

As mentioned earlier, ischaemic stroke can be due to thrombosis, embolism or systemic hypoperfusion.

Thrombotic stroke

Thrombotic strokes are those in which clot formation reduces blood flow, or a clot breaks off and travels to a later part of the blood vessel. Thrombotic strokes can be divided into large and small vessel disease. Thrombosis-related symptoms progress in a stepwise or stuttering fashion, with some periods of improvement.

Embolic stroke

Embolism (particles of travelling debris originating elsewhere) may be from the heart, the aorta or other large vessels. Symptoms often start suddenly and improve very quickly.

Systemic hypotension

Reduced blood flow is more global and does not affect isolated regions. Symptoms are more generalised and without a particular focus, in contrast to thrombosis and embolism.

Symptoms of Ischaemic Stroke

Because other conditions (e.g. seizures, syncope, migraine, and low sugar level) may mimic an ischaemic stroke, the doctor will want to find out the following points from the patient/relative:

• Intake of insulin or oral medications for diabetes
• History of a seizure disorder or drug overdose
• Medications on admission
• Recent trauma
• Hysteria

The doctor will also find out about the pace and course of symptoms, risk factors (diabetes, high blood pressure, high cholesterol level, smoking, a strong family history, known heart diseases), previous transient ischaemic attacks (TIA) and activity at the time when symptoms began.

Stroke is associated with a sudden onset of neurological problems:

• Weakness or loss of function on one side of the body
• Impairment of sensation on one side of the body
• Speech difficulty
• Articulation difficulty
• Visual disturbance on one side
• Imbalance, nausea, dizziness, seeing double

Clinical assessment in most patients should be able to determine whether the stroke involves the vessels supplying the front (anterior) part of the brain (anterior circulation syndrome), back (posterior) of the brain (posterior circulation syndrome), or small vessels supplying a small part (lacunar syndrome).

Generally, anterior involvement causes weakness, sensory loss, visual defect and speech difficulty. Posterior involvement leads to imbalance, dizziness, and seeing double. A stroke involving a small vessel is associated with more focused clinical features (e.g. limited to only muscle weakness, or sensory defect, etc).

Clinical Examination of Ischaemic Stroke

The doctor will examine the blood pressure, temperature, pulse rate, heart, eye, pulses in the neck, arms and legs, and also perform a full examination of the nervous system. Signs of injury to the head/neck will also be looked for.

How is Ischaemic Stroke Diagnosed?

Investigations of a stroke patient include:

• Brain computed tomography scan (CT): typical initial imaging study.
• Electrocardiogram (ECG) (heart tracing): to detect heart attack, irregular heart rhythm, enlargement of heart chambers that makes the heart more prone to clot formation
• Chest x-ray: if lung or heart disease is suspected.
• Blood tests: to check blood cells, clotting ability, cholesterol and fats level, kidney function, sugar level, markers for heart attack (if suspected), liver function, pregnancy status in women of child-bearing age, toxicology screen and blood alcohol level (in some patients).
• Ultrasound: of blood vessels in the neck (carotid artery Doppler) - to detect blockage or narrowing of the carotid arteries supplying the brain.
• Ultrasound of the heart (echocardiography).
• In young patients: investigations for conditions that make them more prone to clotting, holes in the heart, etc.

Prognosis of Ischaemic Stroke

Of the 48,000 Australians diagnosed of a stroke each year, approximately 1/3 will die in 12 months, 1/3 will be permanently disabled, and 1/3 will progress past 12 months without permanent disability.

How is Ischaemic Stroke Treated?

Treatment of ischaemic stroke is according to the National Stroke Foundation Guidelines:

General treatment

• Admission to stroke unit is preferable.
• Thrombolysis: treatment to break clots within 3 hours of stroke.
• If CT scan excludes bleeding in the brain, aspirin is given as soon as possible after the beginning of stroke symptoms.
• The ability to swallow will be assessed. If the patient is deemed to be unable to swallow, a speech therapist will be involved. Alternative methods of feeding via a tube will be considered, with possible involvement of a dietitian.
• Physiotherapy referral for mobility and rehabilitation.
• Occupational therapy referral for optimisation of daily functioning.
• Psychosocial issues addressed by psychologist if needed. Stroke is a major risk to depression.

Management of complications of stroke

• Fever will be investigated for any source of infection.
• Prevention of clots in the leg veins with early mobilisation, stockings, and possibly heparin.
• Fall risk will be assessed, and shoulder pain and pressure sores prevented.

Prevention of future events

• Aspirin, or a combination of low dose aspirin and modified release dipyridamole, or clopidogrel, should be given to all patients with ischaemic stroke not prescribed warfarin. 
• Carotid endarterectomy (removal of plaque or clots from the inner wall of the carotid artery in the neck) may be considered if there is significant narrowing or blockage of the artery.
• Warfarin may be considered in certain patients seven days after the onset of an ischaemic stroke.
• Blood pressure reduction.
• Cholesterol reduction with diet and medication.
• Lifestyle modification: smoking cessation, moderate alcohol consumption, weight reduction, low fat and high fibre diet, moderate exercise.

• Liaising with general practitioner
• Post-discharge needs (physical, emotional and social)
• Equipment and adaptations
• Family meetings
• Provision of information

Ischaemic Stroke References

1. Adams HP Jr, Bendixen BH, Kappelle, LJ, et al. Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial. TOAST. Trial of Org 10172 in Acute Stroke Treatment. Stroke 1993; 24: 35.
2. Adams RJ, Chimowitz MI, Alpert JS, et al. Coronary risk evaluation in patients with transient ischemic attack and ischemic stroke: a scientific statement for healthcare professionals from the Stroke Council and the Council on Clinical Cardiology of the American Heart Association/American Stroke Association. Stroke 2003; 34: 2310.
3. American Stroke Association. Impact of stroke [online]. 2006 [cited 2006 June 4]. Available from: URL: http://www.strokeassociation.org/presenter.jhtml?identifier=1033
4. Antithrombotic Trialists' Collaboration (2002). Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. BMJ, 324, 71-86.
5. Ay H, Furie KL, Singhal A, et al. An evidence-based causative classification system for acute ischemic stroke. Ann Neurol 2005; 58: 688.
6. Bruno A, Biller J, Adams HP Jr, et al. Acute blood glucose level and outcome from ischemic stroke. Trial of ORG 10172 in Acute Stroke Treatment (TOAST) Investigators. Neurology 1999; 52: 280.
7. Caplan LR. Laboratory investigations. In: Stroke: A Clinical Approach, 3rd ed, Caplan, LR, Butterworth-Heinemann, Boston, 2000.
8. CAST: Randomised Placebo-Controlled Trial of Early Aspirin Use in 20,000 Patients with Acute Ischaemic Stroke: CAST (Chinese Acute Stroke Trial) Collaborative Group Lancet 349: 9066 1641-49.
9. Eckert B, Zeumer H. Brain computed tomography. In: Cerebrovascular Disease: Pathophysiology, Diagnosis, and Management, vol 2, Ginsberg, MD, Bogousslavsky, J (Eds), Blackwell Science, Boston, 1998, p. 1241.
10. Gent M. A randomized, blinded trial of clopidogrel versus aspirin in patients at risk of ischemic events (CAPRIE), Lancet 1996; 348: 1329-39.
11. Markus HS, Hambley H. Neurology and the blood: Haematological abnormalities in ischaemic stroke. J Neurol Neurosurg Psychiatry 1998; 64: 150.
12. Markus HS. Current treatment in neurology: stroke. J Neurol 2005; 252: 260-7.
13. National Stroke Foundation. All about stroke [online]. 2006 [cited 2006 June 3]. Available from: URL: http://www.strokefoundation.com.au/pages/Default.aspx?PageID=2&id=1
14. National Stroke Foundation. Clinical Guidelines for Acute Stroke Management [online]. 2006 -cited 2006 June 11]. Available from: URL: http://www.strokefoundation.com.au/pages/Default.aspx?PageID=15&id=1
15. Patel MR, Edelman RR, Warach S. Detection of hyperacute primary intraparenchymal hemorrhage by magnetic resonance imaging. Stroke 1996; 27: 2321.
16. Schaer BA, Zellweger MJ, Cron TA, et al. Value of routine holter monitoring for the detection of paroxysmal atrial fibrillation in patients with cerebral ischemic events. Stroke 2004; 35: e68.
17. The ESPRIT Study Group, Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial, Lancet 2006; 367: 1665-73.
18. The International Stroke Trial (IST): a randomised trial of aspirin, subcutaneous heparin, both, or neither among 19435 patients with acute ischaemic stroke. International Stroke Trial Collaborative Group. Lancet 1997; 349(9065): 1569-81.
19. Touze E, Varenne O, Chatellier G, et al. Risk of myocardial infarction and vascular death after transient ischemic attack and ischemic stroke: a systematic review and meta-analysis. Stroke 2005; 36: 2748.
20. UpToDate: Caplan LR. Classification of stroke [online]. 2006 [cited 2006 June 4]. Available from: URL: http://www.utdol.com/utd/content/topic.do?topicKey=cva_dise/15187&type=A&selectedTitle=9~21
21. UpToDate: Caplan LR. Overview of the evaluation of stroke [online]. 2006 [cited 2006 June 11]. Available from: URL: http://www.utdol.com/utd/content/topic.do?topicKey=cva_dise/11962&type=A&selectedTitle=14~21

Symptoms of This Disease:

• Memory Loss

Drugs/Products Used in the Treatment of This Disease:

• Asasantin SR (Aspirin; Dipyridamole)

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Article Dates:

Modified: 9/2/2010

Created: 2/6/2006