Mechanisms that Produce a Stroke Mechanisms that Produce a Stroke

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Blockage of an artery (80% of strokes)--causes ischemia (inadequate blood flow) This deprives the brain of oxygen and glucose, and slows waste removal --affected brain tissue functions abnormally or stops functioning, and will die if ischemia persists

Rupture of an artery (20% of strokes) --causes hemorrhage within or around the brain. This distorts, compresses, and tears surrounding tissue

Stroke Risk Factors Relationship to pathology Stroke Risk Factors Relationship to pathology

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Directly or indirectly promote conditions that ‘encourage’ blockage or rupture of arteries supplying the brain:• Development of atherosclerotic plaque

• Thrombus formation in heart or cerebral arteries• Physical stress and direct damage to walls of large and small arteries

Stroke Risk Factors Stroke Risk Factors

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Hypertension

Heart Disease Myocardial Infarction Atrial Fibrillation

Diabetes Mellitus

Hyperlipidemia

Carotid Stenosis

Cigarette Smoking

Physical Inactivity

Excess Alcohol Use

Obesity

Age

Gender

Race/Ethnicity

Family History

Prior Stroke/TIA

Medical Conditions (treatable/controllable)

Behaviors / Lifestyles ‘Who We Are’

Stroke Risk Factors Behaviors or Lifestyles Stroke Risk Factors Behaviors or Lifestyles

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Cigarette Smoking• Increases risk about 1.5X• The heavier the smoking, the greater the risk• 5 years after quitting, risk matches that for nonsmokers

Physical Inactivity• Sedentary lifestyle is independent risk factor (30 min. moderate-to-vigorous daily exercise recommended)

Excessive Alcohol Consumption• ≥ 5 drinks/day and binge drinking

Obesity• Body mass index ≥ 30 doubles risk

Stroke Risk Factors Medical conditions: treatable or controllable Stroke Risk Factors Medical conditions: treatable or controllable

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Hypertension• Blood pressure ≥ 140/90 mm Hg for extended periods

Heart Disease• Myocardial Infarction• Atrial Fibrillation

Diabetes Mellitus• Fasting plasma glucose ≥ 126 mg/dL

Hyperlipidemia• Total cholesterol ≥ 240 mg/dL accelerates atherosclerosis

Carotid Artery Stenosis • ≥ 70% narrowing of the carotid artery in the neck

Hypertension is the most significant treatable risk factor!

increase risk of thrombus formationin heart, and thus embolic strokes

Stroke Risk Factors Unmodifiable conditions: ‘Who we are’ Stroke Risk Factors Unmodifiable conditions: ‘Who we are’

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Age• Risk of stroke doubles every 10 years after age 55

Gender• Women’s first strokes occur when they are older

Race/Ethnicity• African-Americans 60% more likely to have a stroke, and twice as likely to die compared to other groups

Family History• First-degree relative with stroke• Inherited defects influencing blood clotting

Previous Stroke or TIA• 1:6 ischemic stroke survivors has another stroke in 2 yrs• Having a TIA increases the chances of stroke 10 times

Basilar Artery atherosclerotic plaque narrows lumen ( )

Basilar Artery atherosclerotic plaque narrows lumen ( )

plaqueplaque

Aorta - Atherosclerosis Numerous ulcerated plaques

Aorta - Atherosclerosis Numerous ulcerated plaques

Carotid Bifurcation atherosclerotic plaque and thrombus Carotid Bifurcation atherosclerotic plaque and thrombus

plaque

Thrombus onplaque surface

Thrombus onplaque surface

Embolus Plugging Artery Piece of thrombus that traveled from heart Embolus Plugging Artery Piece of thrombus that traveled from heart

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Plugged lumen

Intracerebral Hemorrhage Intracerebral Hemorrhage

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Clotted blood

Intracerebral Hemorrhage CT Scan - 3 Hours after onset of symptoms

Intracerebral Hemorrhage CT Scan - 3 Hours after onset of symptoms

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