The Chicago Neuroscience Institute (CNI) is concerned with identifying a patient's risk factors for heart disease, peripheral vascular disease and stroke. CNI is also committed to helping patients modify their lifestyle to reduce the possibility of heart disease and stroke. Stroke represents one of the leading causes of death and disability in the United States.
Stroke risk assessment at CNI addresses the detection and modification of risk factors. Stroke risk screenings are offered to help identify modifiable risk factors such as body mass index, blood pressure, diet, abnormal lipid (blood fat) levels, high levels of systemic inflammatory biomarkers, the presence of atherosclerosis (blocked arteries), the presence of microvascular disease, and impaired blood glucose (sugar) regulation.
One of the primary objectives of this program under the auspices of the CNI Center for Neurological Health is to help individuals identify and subsequently reduce their risk for stroke and other forms of cardiovascular disease which may result in neurological compromise. Stroke risk factors are placed into one of three categories of risk which are modifiable risk factors, non-modifiable risk factors and additional factors.
Stroke is dangerous and deadly. It represents one of the leading causes of death and disability in the United States. Many of the risk factors for stroke can be modified or controlled..
High cholesterol levels are a risk factor for stroke. Cholesterol levels can be determined through the use of a safe and simple blood test often referred to as a lipid panel or profile. A comprehensive lipid panel can be used to evaluate different lipid types and levels. It may also include other specialized biomarkers for cardiovascular disease.
There are three main components of cholesterol which are; low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides. The LDL or "bad" cholesterol is the component associated with increased risk for developing blockages within arteries. Elevated levels of LDL increase the risk for developing heart disease, peripheral arterial disease, stroke and other health problems. The HDL or "good" cholesterol helps remove the LDL from the bloodstream. Higher levels of HDL help reduce the risk of cardiovascular disease. The term triglycerides refer to the fatty substance stored in fat cells within the body. Elevation of the blood triglyceride level can be caused by diabetes, hypothyroidism, and weight gain, excessive intake of alcohol, a fatty diet, kidney disease or liver disease. Special lab testing may be used to evaluate subtypes of HDL and LDL cholesterol.
The carotid arteries refer to the large pair of arteries located on each side of the front of the neck. They provide the primary blood supply to the brain. Fatty deposits and plaque can build up in the carotid arteries leading to critical narrowing, thus reducing the blood supply to the brain resulting in stroke. The progression of carotid artery disease is often silent (asymptomatic) If the plaque becomes ulcerated pieces can break loose, travel to the brain and/or to the back of the eye (retina) and block a blood vessel resulting in stroke. The buildup up plaque in an artery is referred to as atherosclerosis. The presence of significant atherosclerosis (blockages) in one or more carotid arteries is associated with increased risk for the presence of the same process in other areas of the circulatory system including the heart.
Abnormal heart rhythms (arrhythmias) often occurs secondary to disorders of the heart's electrical system. An irregular heart rhythm causes the heart to pump less effectively. Normally, every heartbeat originates from a specialized group of cells with the upper right chamber of the heart (right atrium). This group of specialized cells is referred to as the sinoatrial or SA node, the sinus node or "pacemaker" of the heart. Signal spreads from the SA node throughout the atria (upper heart chambers) to the atrioventricular (A-V) node, another specialized group of cells near the middle of the heart. The A-V node connects to a group of specialized nerve fibers in the ventricles (lower heart chambers) which conduct the electric signal. The impulse travels down all of the specialized fibers to all parts of the ventricles causing the heart muscles to contract and facilitate blood flow. An exact route of bioelectrical signal propagation must be followed for the heart to pump properly and efficiently.
An irregular heart rhythm (arrhythmia) may occur for a number of reasons. Causes include chemical imbalances in the blood, coronary artery (large vessel) disease, microvascular disease (small vessel) in the heart muscle, autonomic (nerve) disorders, heart valve disorders, injury to the heart, and any condition which reduces blood flow to the heart. Prescription drugs may also have a positive or negative effect on the development of heart arrhythmia. Any condition which compromises the normal pacemaker (specialized group of cells) function in the heart will also lead to heart rate and rhythm abnormalities.
Atherosclerosis is a condition characterized by stiffening and narrowing of medium and large sized arteries. This process typically begins with blood vessel wall inflammation and the build-up of fatty substances or cholesterol on the interior portion of the artery wall. The build-up is often referred to as plaque. The development of plaque may partially or totally block blood flow through an artery. This process can cause a stroke in the brain, a heart attack or injury to another organ. The presence and degree of a blockage within an artery cannot be confirmed through the use of blood tests like cholesterol. Direct imaging of a blood vessel is required to confirm the presence of atherosclerosis (plaque). There are different methods which can be used to image blood vessels and/or blood flow through the vessel. One of the safest and most common methods is diagnostic ultrasound. .
Peripheral arterial disease (PAD) refers to diseases of blood vessels (arteries) outside the heart. This includes blood vessels of the neck, abdomen and extremities. It is a condition similar to coronary artery disease (CAD). In PAD fatty deposits build up along the interior of artery walls (plaque). The process can compromise blood flow to any tissue or organ in the body the blood vessels serve. This includes the brain, spine, kidneys, muscles, intestines, peripheral nerves, and bone. People with PAD have a higher risk of death from stroke and heart disease. Peripheral arterial disease can be classified as large blood vessel disease (macroangiopathy) or small blood vessel disease (macroangiopathy).
The maintenance of blood viscosity (thickness) and clotting balance is a complicated process. Blood clotting or coagulation is a protective mechanism of the body to help seal up an injured blood vessel. In normal individuals, coagulation typically begins within 15-20 seconds after injury to a blood vessel. The availability and integrity of a specialized group of cells in the blood referred to as platelets along with a cascade of interdependent chemical events determines the pattern of clotting which occurs. There are many conditions which can adversely influence blood clotting mechanisms by either promoting the development of too much clotting or not enough. Both conditions increase the risk for tissue injury and stroke.
Heart failure refers to conditions which weaken the heart muscles capacity to contract and perform work. Subsequently, the heart becomes less capable of efficiently pumping blood through the lungs, to the brain and to the rest of the body. Progressive weakness of heart muscle leads to stretching of the muscle and enlargement or dilation of the associated chamber or chambers within the heart. This process leads to further failure of the hearts ability to pump blood. Abnormal movement of blood through the heart chambers can lead to the formation of blood clots (thrombi) which can travel and result in blood vessel blockage outside the heart. When an injury occurs in the brain as a result of this mechanism the condition is often referred to as an embolic stroke. The most common causes of heart failure include heart valve disorders, injury to heart muscle (heart attack), coronary artery disease, lack of blood supply to the heart, chronic lung disease and heart muscle disease. Hear failure for the reasons described increases the risk for stroke.
There are many medical conditions including infection, diabetes, metabolic syndrome and autoimmune disease which can trigger an inflammatory response in the blood and subsequently cause inflammation of the blood vessel walls. Research has identified some measurable circulating biomarkers (chemicals) in the blood which represent the presence of or the risk for blood vessel inflammation. Chronic blood vessel inflammation is felt to be a precursor as well as a contributing factor to the development of atherosclerosis. Blood vessel inflammation increases the risk for stroke .
There are four valves in the heart which are referred to as the mitral valve, tricuspid valve, pulmonary valve and aortic valve. Each heart valve opens and closes in synchrony with heart muscle contraction. The valves open and close in a particular sequence allowing each chamber of the heart to contract and propel the blood in one direction. The pattern of heart valve opening and closing is related to the pressure on each side of the valve. The two atrioventricular valves (mitral and tricuspid) ensure that blood flows from the top chambers of the heart (atria) to the bottom chambers (ventricles). The two semilunar valves (aortic and pulmonic) are located in the blood vessels which leave the heart and prevent blood from flowing back into the heart.
There are many conditions and diseases which can compromise one or more heart valves. Some conditions are acquired; whereas; others are developmental (congenital). Acquired conditions include infection, chronic inflammation, clot formation, age-related degeneration and surgery. One of the most common causes of acquired heart valve abnormalities in adults is age-related wear and tear. This process is exacerbated by long-standing arterial hypertension (high blood pressure). In children, one of the most common causes of heart valve problems is developmental malformation arising from birth. Any condition which leads to enlargement of one or more heart chambers can lead to the development of valve incompetence resulting in leaking of blood in the wrong direction during a heart contraction. Blood flow across a heart valve in the wrong direction, if severe enough, may eventually lead to congestive heart failure. Heart valve disorders can reduce blood flow, lower blood pressure and facilitate abnormal blood clotting, all of which increase stroke risk. .
The health and integrity of all bodily tissues including the brain is dependent on adequate large and small blood vessel blood flow. The phrase microvascular disease (MVD) refers to disorders which compromise small blood vessels. MVD can result in cell injury (ischemia) or cell death (infarct). Impaired blood flow in the brain as a result of MVD may result in a stroke. The presence of microvascular disease increases the risk for stroke. Conditions which increase the risk for acquiring microvascular disease include aging, atherosclerosis, diabetes, high blood pressure, insulin resistance, estrogen deficiency, autoimmune disorders and arteriosclerosis (stiffening of the artery). One of the best methods for evaluating the presence of microvascular disease is retinal (eye) imaging.
Excess body weight and obesity are linked to increased risk of high blood pressure, diabetes, heart disease and stroke. High visceral (organ) fat levels increase the risk for developing diabetes and related complications, many of which are associated with increased risk for stroke. Losing as little as 5 to 10 pounds can make a significant difference in your risk. Monitoring body weight is important, although it is also important to periodically have accurate body composition analysis performed. This can reveal body fat mass, lean (muscle) mass, visceral fat estimates, percent body fat, body mass index (BMI) and water distribution.
High blood pressure, or arterial hypertension, is one of the leading causes of stroke and one of most modifiable risk factors. It is therefore important to know your numbers and keep them low.
The nicotine, carbon monoxide and other byproducts in cigarette smoke can damage the cardiovascular system; thus, increasing the risk for stroke. The use of birth control pills combined with cigarette smoking amplifies stroke risk.
Diabetes mellitus is an independent and modifiable risk factor for stroke. If you have Type 1 or 2 diabetes it is imperative that you control your blood sugar. Successful control requires regular monitoring and lifestyle changes. Diabetes mellitus contributes to the development of additional risk factors for stroke such as high blood pressure, high blood cholesterol, and abnormal patterns of blood fats (dyslipidemia) and being overweight. Diabetes is often associated with high levels of visceral (organ) fat, reduced muscle mass (lean mass) and increased body fat mass. Well managed diabetes reduces the risk for stroke, although individuals with the disease still have higher than normal risk.
Diets high in saturated fat, trans fat and cholesterol can raise blood cholesterol levels. Diets high in sodium (salt) can increase blood pressure due to fluid retention. High caloric diets can lead to obesity including increased visceral fat levels. Research has revealed that a diet consisting of five or more servings of fruits and vegetables each day may reduce the risk of stroke.
Physical inactivity has been associated with increased risk for developing heart disease, overweight/obesity, high blood pressure, high blood cholesterol and diabetes, all which increase your risk for stroke. It is important to exercise on a regular basis. It is also important to move throughout the day. Prolonged sitting and general inactivity increase the risk for high blood pressure and obesity.
The phrase hemolytic anemia refers to disorders associated with abnormal shapes and fragility of red blood cells which carry oxygen. The two most common forms of hemolytic anemia are thalassemia (Mediterranean Anemia) and sickle cell anemia. Both conditions represent genetic disorders. Sickle cell anemia mainly affects African-American and Hispanic children. It is associated with abnormally shaped (sickled) red blood cells which are less able to carry oxygen to the body’s tissues and organs than normal red blood cells. In both conditions disfigured cells tend to be fragile and break apart (hemolysis) easy. They also tend to stick to blood vessel walls, a consequence which can result in reduced blood flow and tissue injury. When this process occurs in the brain it is referred to as a stroke. Work with your health care provider to prevent flare ups and manage them carefully.
Other form of Heart Disease
Individuals who have coronary artery disease and/or heart failure are at greater risk for stroke than individuals with healthy hearts. Heart conditions which lead to turbulent or abnormal blood flow within the heart chambers increase the risk for activation of blood clotting mechanisms; thus, increasing the risk for stroke. Heart conditions associated with increased risk for stroke include dilated cardiomyopathy, heart valve disease, and hereditary (congenital) heart defects
The risk of having a stroke increases with age for males and females. The likelihood of stroke is increased in individuals over 65 year of age, although stroke can occur at any age. If an immediate family member (father, mother, brother or sister, son or daughter) has had a stroke under age 65 you may be at greater risk. Some risk factors for a stroke may be genetic. This includes disorders like CADASIL which can occlude blood vessels in the brain..
African-Americans and Hispanics have a much higher incidence of stroke and risk of death from stroke than Caucasians. The higher risk is associated with contributing disorders such as high blood pressure, diabetes and obesity.
Women are at greater risk of stroke than men. Death associated with stroke is also greater in women. Women tend to live longer than men and are older when they have a stroke. Unique stroke risk factors in women include pregnancy, history of preeclampsia/eclampsia or gestational diabetes, oral contraceptive use (especially when combined with smoking) and post-menopausal hormone therapy. It is important that women discuss their personal risk factors with their attending healthcare providers.
Any individual who has had a prior stroke has a much greater risk for stroke than the individual who has not had an event. Individuals with a history of recurrent transient ischemic attacks (TIA) are over 10 times more likely to have a stroke than someone of the same gender, age and sex who has not had TIAs. A TIA refers to a brief period of reduced blood flow to an area of the brain resulting in temporary signs and symptoms which often resolve without a permanent deficit of function. The condition may be caused by a fixed blockage, an embolus (traveling clot) and/or a drop in blood pressure through an area of the brain.
Individuals who have had a prior heart attack are also at increased risk for having a stroke. A heart attack is typically caused by plaque buildup in one or more blood vessels (coronary arteries) which serve the heart. The presence of plaque buildup in the arteries of the heart often parallels a similar process in other arteries, including those in the brain and within other organ systems.
Strokes tend to be more common within southeastern states, an area sometimes referred to as the “stroke belt” states.
The incidence of stroke is generally higher in populations with lower incomes. Contributing factors may include poor dietary habits, as well as higher smoking and obesity rates. Individuals with lower incomes may also have limited access to regular and quality healthcare.
Alcohol abuse can lead to medical complications, including stroke. If you drink alcohol, the American Heart Association/American stroke Association recommends no more than two drinks per day for men and no more than one drink per day for non-pregnant women. Pregnant women should not drink Alcohol abuse can lead to risk factors for stroke such as hypertension, diabetes in the development of blood clotting abnormalities.
The most commonly abused drugs, including cocaine, amphetamines and heroin, have been associated with increased risk of stroke. The strokes associated with drug abuse occur more frequently in younger populations due to the higher incidence of illicit drug use and substance abuse.
Research has revealed that inadequate restorative sleep can lead to high blood pressure (arterial hypertension) and higher stress levels throughout today. Chronic sleep deprivation has also been associated with greater risk for obesity, edema, diabetes and hypertension, all risk factors for stroke. Sleep disorders such as sleep apnea which reduce oxygen levels during the sleep cycle may contribute to chronic vascular inflammation and increased risk for stroke during the hypoxic (low oxygen) periods while sleeping. The presence of acute or chronic lung disease may amplify stroke risk associated with sleep disorders.