Mechanisms that Produce a Stroke Mechanisms that Produce a Stroke Lumen ventricle Blockage of an...
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Transcript of Mechanisms that Produce a Stroke Mechanisms that Produce a Stroke Lumen ventricle Blockage of an...
Mechanisms that Produce a Stroke Mechanisms that Produce a Stroke
Lumen
ventricle
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
Lumen
ventricle
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
Lumen
ventricle
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
Lumen
ventricle
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
ventricle
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’
Lumen
ventricle
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
Lumen
ventricleArterial wall
Plugged lumen