Mechanisms that Produce a Stroke 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 ventricle Lumen

Stroke Risk Factors Relationship to pathology Directly or indirectly promote conditions that ‘encourage’ blockage or rupture of arteries supplying the brain: ventricle Development of atherosclerotic plaque Thrombus formation in heart or cerebral arteries Physical stress and direct damage to walls of large and small arteries Lumen

Stroke Risk Factors Hypertension Heart Disease Diabetes Mellitus Behaviors / Lifestyles ‘Who We Are’ Medical Conditions (treatable/controllable) 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 ventricle Lumen

Stroke Risk Factors Behaviors or Lifestyles 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 ventricle Lumen

Stroke Risk Factors Medical conditions: treatable or controllable 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 formation in heart, and thus embolic strokes ventricle

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

atherosclerotic plaque narrows lumen ( ) Basilar Artery atherosclerotic plaque narrows lumen ( ) plaque

Aorta - Atherosclerosis Numerous ulcerated plaques

atherosclerotic plaque and thrombus Carotid Bifurcation atherosclerotic plaque and thrombus Thrombus on plaque surface plaque Thrombus on plaque surface

Embolus Plugging Artery Piece of thrombus that traveled from heart Arterial wall ventricle Lumen Plugged lumen

Intracerebral Hemorrhage ventricle Lumen Clotted blood

Intracerebral Hemorrhage CT Scan - 3 Hours after onset of symptoms ventricles