RECENT ADVANCES IN THE TREATMENT OF STROKE ESSAY
CHAPTER ONE
1.0     Introduction
1.1     Stroke
1.2     Stroke and the human brain
CHAPTER TWO
2.0     Risk factors and stroke prevention
2.1     High blood pressure
2.2     Heart diseases
2.3     Smoking
2.4     Diabetes
2.5     Cholesterol
2.6     Obesity and Inactivity
2.7     Oral contraceptives and estrogen replacement therapy
2.8     Heredity and family history
2.9     An earlier stroke
2.10   Carotid bruit
2.11   Other risk factors
CHAPTER THREE
3.0     Categories of stroke
3.1     Ischemia stroke
3.2     Hemorrhage stroke
3.2.1  Brain or Intracerebral Hemorrage
3.2.2  Subarachnoid Hemorrhage
3.2.3  Aneurysm
3.2.4  Arteriovenous Malformation
3.2.5  Other forms of stroke                                                                         
CHAPTER FOUR
4.0     Diagnosing and Assessing stroke
4.1     History and Examination
4.2     Laboratory Tests
4.3     Imaging Studies
4.4     Cardiac Evaluation
4.5     Angiography
4.6     Ultrasound
4.7     Blood-flow Studies
CHAPTER FIVE
5.0     Recent advances in the treatment of stroke
5.1     Treatment of acute stroke
5.2     Antiplatelet medications
5.3     Surgery
5.4     Pharmacological approach
5.5     Alternative stroke treatment
References
CHAPTER ONE
1.0    INTRODUCTION
1.1    STROKE
Stroke is a form of cardiovascular disease affecting the blood supply to the brain. Also referred to ascerebrovascular disease or apoplexy, strokes actuallyrepresent a group of diseases that affect about one out of five people in the United States (Demarin et al., 2001). When physicians speak of stroke, they generally mean there has been a disturbance in brain function, often permanent, caused by either a blockage or a rupture in a vessel supplying blood to the brain.
In order to function properly, nerve cells within the brain must have a continuous supply of blood, oxygen, and glucose (blood sugar). If this supply isimpaired, parts of the brain may stop functioningtemporarily. If the impairment is severe, or lasts longenough, brain cells die and permanent damage follows (Kopito, 2001).Because the movement and functioning of variousparts of the body are controlled by these cells,they are affected also. The symptoms experienced bythe patient will depend on which part of the brain isaffected.
While the incidence of stroke has decreased agreat deal over the past few decades, there is evidencethat this trend may be leveling off.Stroke is costly. The cost in human terms, to patientsand their families, is impossible to estimate. Although stroke is often viewed as a disease of theelderly, it sometimes affects younger individuals. Theincidence of stroke does increase with age, but nearlya quarter of all strokes occur in people under the ageof 60 (Demarin et al., 2001).
Stroke patients are often cared for by neurologists,because of the complex nature of the symptomscaused by damage to the brain. However, strokes arevery closely related to heart disease. Heart attacks(myocardial infarctions) and stroke are both causedby diseases of the blood vessels. They share many ofthe same risk factors, and modifying these risk factorsmay reduce the possibility of stroke. Many of the therapiesused for cardiac disease show promise for sometypes of stroke. People who already have coronarydisease may be at greater risk for stroke, andvice versa.
1.2    Stroke and the human brain
To understand the signs and symptoms of stroke andwhy they can differ from patient to patient, it is necessaryto understand a little about the brain and how it functions. There are literally thousands of possiblesymptoms that can result from a stroke, dependingon which blood vessels and parts of the brain areinvolved (Safavi-Abbasi et al., 2006).  It is also important to realize that except fora brief period after birth, brain cells are unable todivide and form new cells. When brain cells die, theyare not replaced. This is part of the reason for thelimited ability of the brain to repair itself after injury,and why recovery from stroke is only partial in manycases. While someone who suffers a heart attack, forexample, can lose 10 percent of heart tissue and stillrun a marathon, losing 10 percent of the tissue incertain parts of the brain can result in a devastatingdisability.
The human brain is the most complex structureknown. It is composed of 100 billion nerve cells, calledneurons; each neuron may connect to thousands ofother brain cells. The trillions of connections are necessaryfor the integrative power of the brain. Theyalso control body movements, interpret all sensations(hearing, vision, touch, balance, pain, taste, andsmell), and mediate thought and language. Differentareas of the brain control different functions (Vahlgren et al., 2007).
Although the brain represents only 2 percent ofthe body's weight, it uses about 25 percent of thebody's oxygen supply and 70 percent of the glucose(sugar). Unlike muscles, the brain cannot store nutrients,and thus it requires a constant supply of glucoseand oxygen. If the blood supply is interruptedfor as little as 30 seconds, unconsciousness results;permanent brain damage may follow in as little asfour minutes. The brain’s high metabolic rate, sensitivityto changes in blood flow, and dependence oncontinuous blood flow are what can make strokes sodangerous.The brain can be divided into three areas: brainstem, cerebellum, and cerebrum. The brain stem controlsmany of the body’s basic functions, includingbreathing, chewing, swallowing, and eye movements (Safavi-Abbasi et al., 2006).
The major pathways from the cerebrum—thethinking part of the brain—also pass through thebrain stem to the body. The cerebellum, attached tothe back of the brain stem, coordinates movementsand balance.
The cerebrum is divided into two hemispheres, leftand right. In general, the left brain receives input(sensations) from the right side of the body and controlsmovement on the right side, so that a stroke inthe right side of the brain will cause left-sided weakness.Conversely, the right brain controls the left sideof the body.Each side of the cerebrum is further divided intofour lobes. The frontal lobes control motor function,planning, and expression of language. The temporal lobes are involved with hearing, memory, and behavior.The parietal lobes interpret sensation andcontrol understanding of language. The occipitallobes perceive and interpret vision. The right and theleft sides of the cerebrum are not identical, but ratherhave specialized functions. In almost all right-handedpeople and most left-banders, the left brain is “dominant”and performs most language functions. Theright side of the brain controls the abilities to understandspatial relations and recognize faces, as well asmusical ability. It also helps focus attention (Alexandrov et al., 2004).