Nhina Sandeep S. de Rosas

Chapter 1: What Is Stroke All About? Stroke, or CVA, is a condition in which blood supply to the brain cells is severely disrupted, causing eventual cellular death. The resulting cellular death leads to a decline in the overall functioning of an individual. In some cases, people who have suffered from an attack of stroke develop disabilities and difficulty in functioning that may or may not be reversible. This definition is one of the easiest to understand and will be one of the focus of this book. The World Health Organization, however, released their own definition in the 1970’s. According to the WHO, a stroke is a neurological deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours. This definition, which is considered by most medical professionals as straight to the point, illustrates exactly the irreversibility of damage to the tissues caused by stroke and sheds light on the possibility of life-threatening conditions associated with it. The 24-hour time period, as pointed out in the definition is arbitrary but essential differentiating stroke from a TIA or transient ischemic attack (NIH, What is Stroke?, 2014). A TIA is a condition that is closely related to stroke characterized by episodes of decreased oxygen supply to the brain. However, the condition rarely lasts for more than a few minutes and very few individuals suffer from permanent effects or disabilities related to TIA. Because of these distinctions between TIA and stroke, more and more individual prefer to use alternate terms to indicate stroke such as acute cerebrovascular syndrome. Some literatures also refer to stroke as brain attack. This naming makes it easier to understand the urgency of action needed when such incidences occur (NIH, How A Stroke Is Diagnosed?, 2014). Stroke, as mentioned in the previous section, may be classified into two major categories which are termed as hemorrhagic or ischemic. This classification is based on the nature of the interruption of blood supply. These two categories are discussed in detail in the following sections (NIH, Types of Stroke, 2014). Ischemic Stroke Ischemia, as defined in the medical literature, is a situation where blood supple to the tissues or cells of the body is impeded, thereby decreasing oxygen delivery to them as well. An ischemic stroke occurs when the delivery of blood into the brain and its cells is interrupted because of a number of reasons. One of the main reasons is the presence of thrombosis or clots along the vessels supplying the brain. When these thomboses gets detached from the vessel walls where they are anchored, they are now termed as emboli. Emboli, or embolism, is another major factor that causes the occurrence of ischemic strokes because the clots can travel to other vessels of the body and cause obstruction in blood flow. The third possible reason for the occurrence of ischemic stroke is the marked reduction in blood circulating the body as in the case of hypovolemic shock. When this happens, the remaining circulating blood is not sufficient to send oxygen to cells of the body, causing them to decline and eventually die. And lastly, the presence of venous thrombosis is also pointed out as one of the risks for the development of stroke among patients with peripheral vascular diseases. Ischemic strokes are also classified based on the extent of its effects upon the brain. Certain areas of the brain that is affected by an ischemia may present differently from one another and there are some that occurs more often than others. One of the most common among these is the total anterior circulation infarct or TACI. There are other several common types such as the lacunar infarct, posterior circulation infarct and the partial anterior circulation infarct. The Causes of Ischemic Stroke Ischemic stroke may be caused by several factors. A majority of stroke cases diagnosed has links with the development of thrombosis, which is partly caused by a narrowing of the blood vessels. This narrowing is termed as atherosclerosis and the condition is due to the presence of cholesterol deposits along the walls of the blood vessels. Most atherosclerosis linked to the development of stroke are found among larger arteries that supply blood to the brain. An embolism, or a traveling clot into the bloodstream, is also pointed out as a causative factor for the development of ischemic stroke. These emboli normally originate from the heart and travel to the brain via systemic circulation. When the clot reaches a smaller vessel, it may be enough to cause a blockage there and lead to ischemia. Other risk factors that physicians point out as a cause for stroke includes use of cocaine or methamphetamine. In some instances where the real reason for the presence of strokes cannot be pointed out, it is termed as idiopathic (unknown). Hemorrhagic Strokes Another major form of strokes is the hemorrhagic stroke. Hemorrhage is the medical term used and applied to denote the presence of bleeding inside or outside the body. A hemorrhagic stroke, however, is a condition where there is bleeding inside the skull and the cells of the brain suffer from decreased in oxygen and eventual death of these cells. There are several types of hemorrhagic strokes but the most commonly known are the epidural hematoma and the subdural hematoma. A stroke caused by an epidural hematoma occurs due to the presence of bleeding in the space between the skill and the dura mater. On the other hand, a stroke that is termed as subdural hematoma is caused by bleeding in the subdural space (the space that develops between the epidural and arachnoid space in the brain). There is also a subarachnoid hemorrhage which is caused by a bleeding between the brain’s pia mater and the arachnoid mater. Cerebral hemorrhage is another causative factor for stroke. This happens where there is actual bleeding that accumulates in the brain’s tissues. It may be related to presence of bleeding in the brain’s parenchyma (brain tissues) or blood pooling within the ventricles of the brain. In most cases, a hemorrhagic stroke is related to a history of head injury and most individuals who suffered from this type of stroke complained of bouts of headaches. Who Are The Most Affected? Strokes can occur to anyone, regardless of their age. In fact, in the year 2011, it was considered to be the second most fatal disease. Stroke has actually taken the spot right after heart disease and before cancer. It has accounted for over 11 percent of deaths worldwide and the number of people increases as the years goes by. The fact that people suffering from stroke getting younger and younger in developing countries is a testament that lifestyle factors is one of the most common reasons for the existence of stroke. However, we cannot discount the fact that over 60 percent of persons affected by stroke is aged 60 and over (NIH, Who Is At Risk for Stroke?, 2014). Research has shown that among all those diagnosed with stroke worldwide, people of South Asian descent have high risk to develop the disease. Almost 40 percent of all deaths related to stroke occur among South Asians (Collaborators, 2014). In the United States, stroke is one of the major causes of disabilities. Among all cases of strokes in the United States, people from the southeastern states have higher number of cases than the rest of the country. The following information was gathered on a study conducted in this demographic group: 1. People aged 30 and older have increased incidences of stroke cases. 2. Almost 95% of all identified stroke cases were seen among those ages 45 years old and above. 3. In the 95%, almost 70 percent of patients were aged 65 and older. 4. The risk of development of disabilities and even death with stroke increases depending on the age when the first attack occurred. 5. There is higher risk for a person to develop stroke when an attack has occurred in one or more members of his family. 6. Males have been found to have almost 30% increased risk to develop strokes as compared to women. 7. Higher percentage of stroke cases leading to death or permanent disability appear in more women than men. 8. Among women, those who have had menopause and undergoing hormone replacement therapy have higher risks for stroke development. Based on these information, it would be worth to note that although stroke affects mainly older individuals, it is not saying that younger people have no risk to develop the disease. Lifestyle factors such as high fat intake, cigarette smoking, sedentary lifestyle and high stress levels also contribute to the development of stroke. Stroke is a serious medical problem and arming ourselves with the right knowledge would allow us to battle stroke and prevent it from happening. Chapter 2: How Do I Know if I Have Stroke? In this chapter, the usual signs and symptoms of stroke will be identified and how to tell it differently from other disease conditions. But first, it is worth remembering that the usual signs and symptoms of stroke as experienced by most individuals who have suffered from it occurs suddenly. In most cases, these symptoms develop in a short span of time that leaves the individual no idea that a stroke is actually happening. The Symptoms and the Extent of a Stroke Symptoms of stroke may either continue to cause further damage in the tissues or stop and allow affected brain cells to heal. The latter occurrence is what usually happens in a transient ischemic attack (TIA). As the symptoms of stroke and its attack goes longer, the associated complications and disabilities also increase. Let’s take for example an ischemic stroke in one small vessel in the brain. If that small vessel is blocked by a clot in a short span of time (say, 2 hours) and the clot was addressed through the use of medications, we can expect the individual to show less signs of an attack of stroke. Now, when the same clot was left in the vessel for longer periods of time, the effects of this would be greater and the risk of complications increases (NIH, What Are the Signs and Symptoms of Stroke?, 2014) (NIH, Types of Stroke, 2014). Stroke and Its Initial Symptoms The symptoms brought about by stroke are not limited to the brain but occurs almost all throughout the body. Mostly, the symptoms felt by the individual and the examination of a doctor on what parts of the body affected gives an idea about where in the brain a stroke has occurred. Of course, this would need to be verified by a laboratory test which we will discuss in the next chapter. Most people who were previously diagnosed or had an attack of stroke present with some of its classic symptoms (NIH, Who Is At Risk for Stroke?, 2014). These symptoms include but are not limited to weakness on one side of the face, difficulty in raising an arm, and slurring of speech. These symptoms are what usually causes alarm for individuals who had stroke attacks and prompts them to seek consult. The presence or absence of the symptoms enumerated above also helps health care practitioners to assess if a person is having a stroke or another similar condition. The presence of all three classic symptoms increases the likelihood that a person is having stroke while its absence may be interpreted that a person is experiencing another medical condition. In the United Kingdom, their Stroke Association and Department of Health together with American Stroke Association and other top American organizations on stroke developed a code to advocate symptoms of stroke and how to detect it as early as possible. They call this the FAST system. FAST stands for face, arm, speech and time. This system allows for medical professionals to effectively and accurately assess the presence of strokes among individuals who are reporting symptoms associated with it. Symptoms of Stroke Depending on Its Subtypes The Three Tracts Not all symptoms associated with strokes are the same. Each area of the brain affected by death of its cells and tissues present with a different set of symptoms by which persons suffering from it may present with. However, there are three major pathways of the nervous system that is affected by strokes and these are (NIH, What Are the Signs and Symptoms of Stroke?, 2014): a. spinothalamic tract b. corticospinal tract c. dorsal column. If any of these tracts were affected by an attack of stroke, the following symptoms may be experienced or reported by persons suffering from them: a. weakness of the facial muscles- this normally cause the affected side of the face to sag; b. weakness or paralysis on one side of the body (also known as hemiplegia); c. feeling of numbness; d. weak and flaccid muscles (muscles lose tone and ability to effectively contract); e. spastic muscles or those that contract excessively; f. involuntary movement sin some muscles; and g. uncoordinated movements. Most individuals who suffered from an attack of stroke developed paralysis on only one side of the body. This side is also usually opposite the side of the brain that is affected by stroke. However, because there are other conditions that may cause paralysis, the presence of hemiplegia cannot be used as a sole basis for diagnosis of stroke (Collaborators, 2014). Brainstem Involvement The brainstem is another area of the brain that is affected by stroke. When this part of the brain gets affected, the cranial nerves and their functioning is compromised. The cranial nerves are those that supplies most organs located in the head such as the eyes or the ears. They govern the sensory and motor functions of these organs. The following symptoms can be seem among those individuals whose stroke affected the brainstem (NIH, How A Stroke Is Diagnosed?, 2014): a. problems or alteration in the sense of sight; b. altered sense of smell and hearing; c. visual disturbances (double vision, squinting, unilateral blindness); d. weakness of the eye muscles and drooping of the eyelids (ptosis); e. problems in the pupil’s reaction to light (this is usually tested by a doctor or qualified health professional with the aid of a pen light); f. decreased gag and swallowing reflexes (usually leads to choking problems); g. difficulty maintaining one’s sense of balance; h. weakness of the muscles that helps the person to turn his head sideways; i. problems in speaking (slurring of speech) which is related to the weakness of the tongue; and k. changes in the breathing pattern and rate of the individual. These symptoms may be seen in any combination in most individuals diagnosed with stroke. In worse cases, some persons present all these enumerated symptoms altogether. When such happens, there is a huge possibility that the stroke he has had is far more advanced. Cerebral Cortex Involvement Most stroke effects and symptoms that involve major pathways of the central nervous system appear more pronounced that those with brainstem involvement. The following symptoms are seen among individuals who have had or is currently suffering from a stroke attack (Mackenzie, 2011) (Murray, Buttner, & Price, 2012): a. problems with language (termed as aphasia, which will be discussed in detail in succeeding chapters of this book); b. difficulty in articulating words (dysarthria); c. uncoordinated voluntary movements (apraxia); d. problems in memory and recall (especially when the stroke affected the temporal lobe); e. uncoordinated visual functioning where objects are seen only on one side of the face (hemineglect); f. lack of attention, agitation and confusion; g. difficulty organizing thoughts; and h. problems in abstract thinking. Cerebellar Involvement The cerebellum is the part of the brain that is responsible for controlling walking and balance. When an attack of stroke affects this part of the brain, the individual may normally exhibit unsteady gait and wobbly walking. They may also be presenting with vertigo and problems maintain an erect posture. Other Symptoms There are other symptoms of the disease that may occur regardless of which part of the brain is affected. These include fainting episodes, vomiting and even complaints of headache with varying intensity. The vomiting is normally caused by an increase in the pressure inside the skull. This rise in pressure may be caused by presence of hemorrhage or swelling of other structures, which causes compression of the brain.