Stroke is widely regarded one of the leading causes of deaths in the U.S. Indeed, recent statistical figures paint a grim picture with regard to the number of people who suffer a stroke in the U.S. each year. In basic terms, strokes are triggered by an interruption of blood flow into the brain. In this text, I concern myself with the physiological processes associated with stroke. In so doing, I will amongst other things define the disease and the body systems it affects, its causes, manifestation, and complications. Further, I will also discuss the hereditary or familial factors commonly associated with stroke.
Stroke: An Overview
In basic terms, stroke is said to be "an abrupt onset of neurological functions caused by a sudden reduction of cerebral blood flow, which is due in turn to either an ischemic occlusion or a hemorrhagic episode" (Gulini, Gianelli, Quaglia, and Marrucci, 2000, p. 239). As a medical emergency, stroke as I have pointed out occurs when blood flow to the brain is interrupted. It is important to note that to function normally, cells in the brain need a constant supply of oxygen. A stroke occurs when the supply of oxygen-rich blood to some portions of the brain is interrupted thus triggering the rapid death of brain cells. Essentially, strokes are classified into two, i.e. hemorrhagic stroke and ischemic stroke (Mohr et al., 2011). Ischemic stroke happens when a blood vessel in the brain is plugged or blocked by a blood clot or other obstruction. On the other hand, a hemorrhagic stroke happens when there is a breakage of a blood vessel that causes or brings about sudden bleeding into the brain. In this case, it is the said bleeding that ends up damaging brain cells. Both ischemic and hemorrhagic strokes can be further divided into two, i.e. embolic stroke and thrombotic stroke, and intracerebral hemorrhage and subarachnoid hemorrhage respectively.
It should also be noted that there is yet another condition known as a transient stroke. Commonly referred to as a "mini-stroke," a transient ischemic as Smeltzer, Bare, Hinkle, and Cheever (2010) point out results when there is a brief blockage of blood flow to a certain portion of the brain. Based on the duration of the blockage, the damage occasioned to the brain cells is in this case not permanent. In most cases, the symptoms of a stroke are manifested in those parts of the body the dead or damaged brain cells control. Some of the most common symptoms of stroke include but they are not in any way limited to a sudden severe headache whose cause is unknown, sudden loss of balance, sudden loss of coordination and feeling of numbness, etc. (Smeltzer, Bare, Hinkle, and Cheever, 2010).
Causes of Stroke
There are many medical conditions that can trigger or significantly increase the risk of stroke. Some of the conditions that are known to cause hemorrhagic stroke include arteriovenous malformations, aneurysms, and high blood pressure. While the first two causes have got to do with the weakening of blood vessels, the latter cause of stroke according to Huether and Mccance (2012) is more often than not associated with both the weakening and narrowing or clogging of blood vessels. Indeed, it has been reported that approximately 77% of those who have a first stroke as Mohr et al. (2011) point out "have blood pressures higher than 140/90 mm Hg." When high blood pressure is not controlled, the likely result is weakening of brain blood vessels. It is these weakened brain blood vessels that burst and cause a hemorrhagic stroke.
As I have already pointed out above, brain aneurysm could also increase the risk of hemorrhagic stroke. A brain aneurysm in basic terms is the ballooning of a brain blood vessel. When the said aneurysm raptures or leaks, there is likely to be a sudden draining of blood into the brain. On the other hand, arteriovenous malformations result from the bypassing of normal brain tissue by a tangle of blood vessels. It is the absence of a capillary bed that brings about the "dilation of the arteries and veins and eventual rupture" (Smeltzer, Bare, Hinkle, and Cheever, 2010, p. 1911).
One of the conditions known to cause or increase the risk of ischemic stroke is large artery atherosclerosis (Mohr et al., 2011). This is essentially a condition that results from the buildup of plaque in the arteries' inner walls. In addition to narrowing the arteries, plaque also ends up hardening the arteries leading to the rupturing or the cracking of the affected artery. The formation of blood clots at the site of injury could result in the full blockage of the artery. One of the conditions that results when there is buildup of plaque in the carotid arteries is carotid artery disease which according to Reiser, Semmler, and Hricak (2007) is regarded a prominent cause of ischemic strokes. There are also a number of other heart conditions that can trigger or cause a stroke. One such condition is atrial fibrillation (Eisenberg, Glueckauf, and Zaretsky, 1999). When it comes to high blood pressure, it should be noted that weakened blood vessels are more susceptible to blockage.
Although some of the other risk factors of stroke will be discussed elsewhere in this text in greater detail, it would be prudent to mention just a few of these. Most common risk factors on this front include but they are not limited to age, sex, family history of the disease, obesity, diabetes, uncontrolled intake of alcohol, diabetes, cigarette smoking, etc. With regard to age and sex or gender, it is important to note that an individual's risk of suffering a stroke increases as he or she gets older. In this case, "strokes increase dramatically with age and tend to double with each decade after age 55" (Eisenberg, Glueckauf, and Zaretsky, 1999, p. 529). Strokes as the authors further point out also tend to affect a significantly lower number of Caucasian and African-American males than that of females (Eisenberg, Glueckauf, and Zaretsky, 1999). Birth pills have also been linked to an increased risk of suffering a stroke in women.
When it comes to race and ethnicity, Mohr et al. (2011) points out that Asians or Pacific Islanders have a lower risk of suffering a stroke than Native Americans. Mortality rates for stroke as the authors further point out are however higher for African-Americans than they are for Native Americans.
How Stroke Manifests Itself
Stages and Evolution of Stroke
Strokes are widely regarded as medical emergencies. In the words of Reiser, Semmler, and Hricak (2007), "the clinical presentation of stroke is variable, but will primarily manifest itself in the form of acute neurological deficits" (p. 311). As the authors further point out, these deficits include but they are not limited to modifications or adjustments in consciousness levels, gait and speech difficulties, visual problems, and paralysis (Reiser, Semmler, and Hricak, 2007).
Possible Secondary Disorder or Complications
The complications associated with a stroke are largely dependent on the part of the brain affected and the period of time that elapses after blood flow to the brain is interrupted. One of the complications of a stroke is loss of muscle movement or paralysis. In addition to loss of control of some muscles, a stroke could bring about paralysis on one side of a victim's body resulting in decreased ability to perform day-to-day activities such as dressing and walking. The victim of a stroke could also in some cases lose his or her ability to control some throat and mouth muscles leading to difficulties in eating or swallowing. This loss of muscle control according to Smeltzer, Bare, Hinkle, and Cheever (2010) could also affect the affected individual's speech leading to condition referred to as dysarthria (slurred speech). Difficulties with language could also be experienced if the sections of the brain damaged or affected are the ones that control language (Smeltzer, Bare, Hinkle, and Cheever, 2010). This according to the authors could lead to a condition referred to as aphasia. Other complications which could come about as a result of a stroke include but they are not limited to thinking difficulties and loss of memory, unusual sensitivity to changes in temperature (central pain syndrome), etc.
Prevention of Stroke and its Complications
One of the most effective approaches towards the prevention of stroke is risk factor control. Risk factors include but they are not limited to all those habits, conditions, or traits that significantly increase an individual's risk of having a stroke. It should be noted that the more risk factors an individual is exposed to, the higher the chances of such an individual having a stroke. While some risk factors of stroke can be controlled and/or treated, some like gender and age can neither be treated nor controlled. When it comes to controllable risk factors, we have diabetes, high blood pressure, and smoking. Others include brain aneurysms and heart disease. Individuals who smoke owe unto themselves to quit. Those who happen to be overweight should also embrace…