stroke ( ischemic stroke )

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Ischemic stroke

DONE BY : MUSTAFA KHALIL IBRAHIMTBILISI STATE MEDICAL UNIVERSITY4th year, 2st semester, 1nd group

Neurology department

Epidemiology IntroductionPathophysiology Risk factors Etiology Signs and symptoms Complications Diagnosis Treatments Prevention Rehabilitation Prognosis References

1- Heart disease: 614,3482-Cancer: 591,6993-Chronic lower respiratory diseases: 147,1014-Accidents (unintentional injuries): 136,0535-Stroke (cerebrovascular diseases): 133,1036-Alzheimer's disease: 93,5417-Diabetes: 76,4888-Influenza and pneumonia: 55,2279-Nephritis, nephrotic syndrome, and nephrosis: 48,14610- Intentional self-harm (suicide): 42,773

Number of deaths for leading :causes of death

Stroke is the 5th leading cause of death in the US and is a major cause of disability.

Annually, 15 million worldwide suffer a stroke-5 million die and 5 million are permanently disabled .

WHO estimates a stroke occurs every 5 seconds.adult ~ 800,000 people in the US have a stroke each

year.

One American dies from a stroke every 4 minutes, on average

killing nearly 130,000 Americans each year, that’s 1 of every 20 deaths.

About 87% of all strokes are ischemic stroke , when blood flow to the brain is blocked.

Stroke costs the United States an estimated 34 -40$ billion each year

Total cost of stroke has been estimated at $65.5 billion in 2008.

 highest death rates from stroke are in the southeastern United States

Annual Economic Costs of Stroke (All Types) In The US

 

Stroke is a syndrome consisting of rapidly developing (usually seconds or minutes) symptoms and/or signs of loss of focal (or sometimes global) CNS function. The symptoms last more than 24 hours or lead to death.

 Although the brain makes up only 2% of our body weight, it uses 20% of the oxygen you breathe.

Stroke types

Ischemia or infarction

embolic thrombotic

hemorrhagic

Intracerebral

hemorrhage

Subarachnoid

hemorrhage

Classification of Stroke

12%

A transient ischemic attack (TIA) is sometimes called a "mini-stroke." It is different from the major types of stroke because blood flow to the brain is blocked for only a short time.

lasting less than 24 hours - usually no more than 5 minutes

caused by embolic, thrombotic or hemodynamic vascular mechanisms.

Some transient episodes last longer than 24 hours, yet patients recover completely – reversible ischaemic neurological deficits.

Transient ischemic attack (TIA) :

 Is characterized by the sudden loss of blood circulation to an area of the brain, resulting in a corresponding loss of neurologic function. Acute ischemic stroke is caused by thrombotic or embolic occlusion of a cerebral artery and is more common than hemorrhagic stroke.

It can occurin the carotid artery of theneck as well as other arteries.

Ischemic stroke

In an embolic stroke, a blood clot or plaque fragment forms somewhere in the body (usually the heart) and travels to the brain. Once in the brain, the clot travels to a blood vessel small enough to block its passage. The clot lodges there, blocking the blood vessel and causing a stroke.

About 15% of embolic strokes occur in people with atrial fibrillation (Afib). The medical word for this type of blood clot is embolus.

: 1 -Embolic stroke

A thrombotic stroke is caused by a blood clot that forms inside one of the arteries supplying blood to the brain.  This type of stroke is usually seen in people with high

cholesterol levels and atherosclerosis. Two types of blood clots can cause thrombotic stroke: large

vessel thrombosis and small vessel disease.  Large Vessel Thrombosis The most common form of thrombotic stroke (large vessel thrombosis) occurs in the brain’s larger arteries. In most cases it is caused by long-term atherosclerosis in combination with rapid blood clot formation. High cholesterol is a common risk factor for this type of stroke.Small Vessel Disease Another form of thrombotic stroke happens when blood flow is blocked to a very small arterial vessel (small vessel disease or lacunar infarction). Little is known about the causes of this type of stroke, but it is closely linked to high blood pressure.

2 -Thrombotic stroke

When an artery is acutely occluded by thrombus or embolus, the area of the CNS supplied by it will undergo infarction if there is no adequate collateral blood supply. Surrounding a central necrotic zone, an ‘ischemic penumbra’ remains viable for a time, i.e. it may recover function if blood flow is restored.CNS ischemia may be accompanied by swelling for two reasons:● cytotoxic oedema – accumulation of water in damaged glial cells and neurones,● vasogenic oedema – extracellular fluid accumulation as a result of breakdown of the blood–brain barrier.In the brain, this swelling may be sufficient to produce clinical deterioration in the days following a major stroke, as a result of a rise in intracranial pressure and compression of adjacent structures.

ATHEROSCLEROSIS AND THROMBOSIS

Atherosclerosis: decades-long process; progression favored by hypercholesterolemia, HTN, cigarette smoking

•Fatty streak: yellowish discoloration on intimal surface of blood

•Focal plaques: eccentric thickening at bifurcations; addition of massive extracellular lipids that displaced normal cells and matrix

•Complicated fibrous plaques: central a cellular area of lipid covered by a cap of smooth muscle cells and collagen

Atherosclerosis and Thrombus Formation:Arterial Wall Injury

Functional alteration of endothelial cell layer

Denuding of endotheliumSuperficial intimal injury

Deep intimal & media damage with marked platelet aggregation and mural thrombosis

Thromboembolism

Cardiogenic Emboli

Cardiogenic emboli lodge in the middle cerebral artery or its branches in 80% of cases,

in the posterior cerebral artery or its branches 10% of the time,

and in the vertebral artery or its branches in the remaining 10% of cases.

THE ISCHEMIC PENUMBRA

less well documented Can be changed, treatable, controlled :

Cannot Be Changed:

• Geographic location- southeastern US > other areas.  so-called "stroke belt" states.

• Socioeconomic factors- some evidence strokes among low-income people > people with high-income .

• Alcohol abuse.• Drug abuse.• Acute infection*

• High blood pressure.• Cigarette smoking.• Diabetes mellitus —Many

people with DM have high BP, dyslipidemia and overweight. 

• Carotid or other artery disease.  

• Peripheral artery disease.• Atrial fibrillation ~ 15% of

embolic strokes occur in people with Afib.

• Other heart disease- CAD or HF …etc

• Transient ischemic attacks (TIA).

• Sickle cell disease.• High blood cholesterol .• Poor diet.• Physical inactivity and

obesity 

• Increased age .• Being male .• Race (e.g., African-

Americans) .• Diabetes mellitus .• Prior

stroke/transient. ischemic attacks .

• Family history of stroke

• Asymptomatic carotid bruit.

• Genetic disorders .

UNCOMMON CAUSES COMMON CAUSES• Hypercoagulable disorders• Protein C deficiency• Protein S deficiency• Antithrombin III deficiency• Antiphospholipid syndrome• Factor V Leiden mutation a• Prothrombin G20210• Mutation a• Systemic malignancy• Sickle cell anemia• β-Thalassemia• Polycythemia vera• Systemic lupus erythematosus• Homocysteinemia• Thrombotic thrombocytopenic• purpura• Disseminated intravascular• coagulation• Dysproteinemias• Nephrotic syndrome• Inflammatory bowel disease• Oral contraceptives• Venous sinus thrombosis b• Fibromuscular dysplasia• Vasculitis

• THROMBOSIS: Lacunar stroke (small vessel) Large vessel thrombosis Dehydration• EMBOLIC OCCLUSION : Artery-to-artery Carotid bifurcation Aortic arch Arterial dissection Cardioembolic Atrial fibrillation Mural thrombus Myocardial infarction Dilated cardiomyopathy Valvular lesions Mitral stenosis Mechanical valve Bacterial endocarditis Paradoxical embolus Atrial septal defect Patent foramen ovale Atrial septal aneurysm Spontaneous echo contrast

ANTERIOR CEREBRAL ARTERY

Contralateral paresis and sensory loss in the leg.

Cognitive or personality changes.

The symptoms last more than 24 hours or lead to death.Symptoms and signs of arterial infarcts depend on the vascular territory affected .

MIDDLE CEREBRAL ARTERY

Pneumonic: “CHANGes”Contralateral paresis and

sensory loss in the face and the arm.

Homonymous Hemianopsia.

Aphasia.Neglect.Gaze preference toward

the side of the lesion.

POSTERIOR CEREBRAL ARTERY

Pneumonic: The 4 D’s

Diplopia

Dizziness

Dysphagia

Dysarthria

BASAL GANGLIA LACUNAR

Pure motor or sensory stroke.

Dysarthria-clumsy hand syndrome, ataxic hemiparesis.

BASILAR ARTERY

Coma “Locked-In” Syndrome Cranial Nerve Palsies Apnea Visual Symptoms Drop Attacks Dysphagia Dysarthria Vertigo “Crossed” weakness and sensory

loss affecting the ipsilateral face and contralateral body.

Brain edema. Pneumonia- occurs as a result of not being able to move as a result

of the stroke. Urinary tract infection (UTI) - can occur as a result of having a

foley catheter .Seizures - common in larger strokes. Clinical depression - very common after stroke or may be

worsened in someone who had depression before the stroke. Bedsores .Limb contractures .Deep venous thrombosis (DVT). myocardial infarction, arrhythmias and heart failure.fluid imbalance.spasticity, with pain, contractures and frozen

shoulder,

Vital signs  Heart rate . Blood pressure. Breathing. Temperature. BMI. O2 saturation Patient history

Physical examination Absent pulses (inferior extremity, radial, or carotid) - favors

atherosclerosis with thrombosis Sudden onset of cold, blue limb- favors embolism. Occlusion of common carotid artery in the neck neck with bruit -

occlusive extracranial disease Temporal arteritis- temporal arteries irregular and with dilatation,

tender, pulseless Cardiac findings(especially atrial fibrillation, murmurs,cardiac

enlargement) - favor cardiac-origin embolism. Carotid artery occlusion –iris speckled, ipsilateral pupil dilated and

poorly reactive, retinal ischemia  Fundus - cholesterol crystal, white platelet-fibrin, or red clot emboli.

Subhyaloid hemorrhage in brain or subarachnoid hemorrhage. 

DIAGNOSIS

levels of cholesterol and sugar in your blood. electrocardiogram (ECG) .ElectrocardiogramComplete blood count including platelets & ESR Cardiac enzymes and troponin Electrolytes, urea nitrogen, creatinineProthrombin time and international normalized ratio (INR),

Partial thromboplastin timeOxygen saturationCoagulation studies: May reveal a coagulopathy and are

useful when fibrinolytics or anticoagulants are to be used

CT ScanMiddle cerebral artery infarct

Posterior cerebral artery infarct

Strokes <6 hours old are usually NOT visible on CT scan.

MRI

acute middle carotid artery (MCA) stroke

CT SCAN MRI

Carotid Duplex (Ultrasound)

Transcranial Doppler

MRA (Magnetic Resonance Angiography)

CT Angiography

Conventional Angiography

Liver function testsToxicology screenBlood alcohol levelPregnancy test in women of child-bearing potentialArterial blood gas if hypoxia is suspectedElectroencephalogram if seizures are suspected

Appropriate in selected patients

Differential Diagnosis of StrokeCraniocerebral / cervical traumaMeningitis/encephalitisIntracranial mass Tumor Subdural hematoma Seizure with persistent neurological signsMigraine with persistent neurological signsMetabolic Hyperglycemia Hypoglycemia Post-cardiac arrest ischemia Drug/narcotic overdose   

● Admission to a stroke unit .● Antiplatelet agents: -Aspirin 300mg daily or Clopidogrel , modest benefit when given within 48 hours of onset,● Thrombolysis: Alteplase ( tissue plasminogen activator (tPA)) -IV Alteplase : within 3 hours of stroke symptom onset -IA Alteplase : within 6 hours. (SBP<185 and SBP <110mmHg.)

● anticoagulant: Warfarin, or HeparinAlso : Endotracheal intubationNasogastric tubeIv fluid to prevent dehydrated

The acute management of ischemic stroke

Management of Cerebral Edema, Increased :Intracranial Pressure and Hydrocephalus

*Brain edema peaks at 3-5 days 1. IV Mannitol (0.25 mg/kg over 20

minutes). 2.hyperventilation (lower PCO2). 3. osmotic diuretics. 4. drainage of CSF (ventriculostomy). 5. surgery (lobectomy).

Reduce fever.Regulate blood pressure. - if severe hypertension IV Labetalol or Nicardipine infusion.Correct hypoxia.Regulate blood glucose.Manage cardiac arrhythmias.Manage myocardial ischemia.

Other treatment

CONTRAINDICATIONS TO ALTEPLASE THERAPY

Pneumonic: SAMPLE STAGES

Stroke or head trauma within the last 3 months.

Anticoagulation with INR>1.7 or prolonged PTT.

MI (recent). Prior Intracranial

Haemorrhage. Low Platelet Count

(<100,000/mm3 ) Elevated BP: Systolic>185

or Diastolic >110mmHg

Surgery in the past 14 days. TIA (mild symptoms or rapid

improvement of symptoms). Age<18 GI or urinary bleeding in the

past 21 days Elevated (>400mg/dl) or

Decreased (<50mg/dl) Blood glucose.

Seizures present at the onset of stroke.

SURGERY

Carotid Endarterectomy to remove blood clots and fatty deposits from one of the carotid arteries (but isn’t suitable for everyone).

CAROTID ENDARTERECTOMY

If stenosis is >70% in symptomatic patients or >60% in asymptomatic patients (Contraindicated on 100% occlusion).

Some patients with cerebellar infarction may require urgent posterior fossa decompression and ventricular drainage if swelling caused by the infarct is leading to brainstem compression and obstruction to CSF flow

SURGERY

Stopping smoking. Healthy diet (low animal fat, low salt, avoiding excess alcohol) and

prescribing cholesterol-lowering agents, i.e. statins. In the long term, control of blood pressure is also important.

For the first 2 weeks after an ischaemic stroke, however, patients should not receive antihypertensive therapy beyond their pre-existing treatment unless there is evidence of malignant hypertension.

This is because too rapid lowering of blood pressure may worsen ischaemia in a region where the cerebral circulation is already compromised.

Lifelong antiplatelet treatment is indicated, commencing as soon as possible after a cerebral infarct. The initial dose of aspirin (300mg daily) can be reduced to 75mg daily after 4 weeks.

Anticoagulation with warfarin is effective prophylaxis in the presence of atrial fibrillation and other cardiac sources of embolism.

Stroke PreventionAnticoagulants (Heparin, Warfarin)Antiplatelets (aspirin, clopidogrel

dipyridamole/ASA combination, ticlopidine)

StatinARB (-sartan), or ACE inhibitor + HCTZCarotid endarterectomy if indicatedCarotid or intracranial stent.Risk factor control!!!

REHABILITATIONA multidisciplinary team of

health professionals will work out a rehabilitation programme for you that’s designed around your particular needs.

Rehabilitation aims to help you stay as independent as possible and get back to your usual activities, or adapt to new ways of doing things.

You may make most of your recovery in the early weeks and months afterwards but you may continue to improve for years.

Factors That Cause Stroke ProgressionHypotensionHyperglycemiaHyperthermiaInfectionCerebral hypoperfusion

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