Introduction
A stroke refers to a sudden loss of the normal functions of the brain that result from an anomaly in the supply of blood into the brain (Mayo Clinic, 2010). There are two distinct types of strokes: ischemic strokes and hemorrhagic stroke. Ischemic strokes are caused by failure of blood supply to reach certain parts of the brain owing to blockage of blood vessel by blood clots (Mayo Clinic, 2010). Blood clots travel to the brain through two main ways. Either from artery to artery or they can originate from the heart.
Causes
Ischemic strokes are mainly caused by blockages in the arteries that supply the brain with blood. Blockage of arteries can occur due to the following factors:
- An instantaneous decrease in blood pressure. In most cases, decreases in blood pressure leads to fainting if on a small scale. However, if it is severe and if it happens for a long period, then it can cause a stroke. This may result from excessive loss of blood, a heart attack or if the heart exhibits abnormal rhythms or rates of beating (Mayo Clinic, 2010).
- Narrowing of arteries caused by inflammation or other arterial infections that lead to narrowing.
- Use of drugs such as cocaine, which cause narrowing of arteries and other blood vessels.
- Breakage of atheroma from the walls of arteries. This material may be transported to small arteries and this may lead to blockage (Mayo Clinic, 2010).
- Blood clots that emanate from the heart and form globules called embolus. These clots can then travel from the heart to the brain and are stuck there. This leads to a health condition referred to as embolic stroke or cerebral embolism (Mayo Clinic, 2010). This class of stroke mostly afflicts individuals who have undergone a heart surgery in the recent past and people whose heart valves are defective.
Strokes have been shown to cause brain swellings. These swellings lead to build up of pressure, which can potentially cause brain tissue damage or aggravate neurologic problems.
Symptoms
Strokes have certain symptoms that characterize them even though some have distinct symptoms that set them apart from the rest. Strokes occur instantaneously, build up very fast and their effects to the brain occur within a very short time (UCSF Medical Center, 2012). Stroke evolution is a characteristic of certain rare stroke occurrences. It involves the worsening of the stroke for up to day as certain brain parts enlarge and consequently die. The severity of the stroke subsides if the affected brain parts stop enlarging. The major symptoms of stroke include:
- Blurred and double vision
- Loss of comprehension and recognition
- Loss of either vision or hearing ability for some time
- Paralysis of certain parts of the body
- Indistinct speech
- Difficulties in expressing oneself
- Dizziness
- Lack of body balance that can result in frequent falls
Diagnosis
Diagnosis of strokes involves an extensive evaluation of events preceding the occurrence and thorough physical examination by a doctor (Flores, 2011). Confirmation can be done through conducting specific diagnostic tests that include CT scanning and MRI. Advanced methods of MRI scans can identify a stroke before emergence of symptoms or a few minutes after symptoms emerge (Flores, 2011). After diagnosis, it is important for the doctor to group the stroke and identify the cause.
Conclusion
Ischemic strokes are caused by failure of blood supply to reach certain parts of the brain owing to blockage of blood vessel by blood clots. Either blood clots travel to the brain from artery to artery or they can originate from the heart. Proper diagnosis and identification of the cause are the most critical aspects.
References
Flores, S. (2011). Ischemic Stroke in Emergency Medicine. Web.
Mayo Clinic: Stroke. (2010). Web.
UCSF Medical Center: Stroke Signs and Symptoms. (2012). Web.