Overview of the Management of Ischemic Stroke
An Ischemic stroke is a medical condition that requires immediate attention. It is a type of brain-related disease that affects the ability of this organ to function properly. More precisely, an ischemic stroke results from a blockade found in any one of the arteries leading up to the brain. Such a blockade is substantial in size because it hinders the flow of blood and makes the artery swell up.
To understand the pathophysiology of ischemic stroke, and to be equipped for the management of ischemic strokes, it helps to take a look at the crucial role that these small arteries play. Since the brain is the single most important control centre of the body, its functioning ability has to be maintained at all times. A complex web of arteries supplies oxygenated blood to the delicate tissues in the brain.
When these tissues take in oxygen and glucose, they give out energy, water and carbon dioxide. While first two by-products are used up by the brain, carbon dioxide needs to be given out. This exchange of gases and constant production of energy takes place on a cellular level, which means thousands and thousands of cells respire when they get fresh, oxygenated blood.
As a result of the proper respiration of these cells (neurons), the brain is able to perform essential sensory and neurological functions, without which the human body becomes crippled. Can you image what will happen if, for a few seconds, the brain cells and tissues do not receive oxygen? The damage is catastrophic.
For an ischemic stroke to occur, the supply of blood to the neurons is hindered. This hindrance may not be fatal in the beginning, taking time to build up gradually. However, when it is big enough to obstruct blood flow, the neurons in the brain are deprived of fresh blood. In a matter of seconds, these sensitive cells can stop working and die out, causing a brain-attack or an ischemic stroke.
According to research, 85%-87% of all strokes are ischemic strokes. Consequently, management of ischemic stroke is life-saving task because this condition has the power to cause irreparable damage to the brain, which leads to crippling bodily abnormalities.
For caregivers, the management of ischemic strokes encompasses getting adequate information about this condition, while for doctors and physicians, it is to be trained in the best treatment methods to provide excellent care.
Ischemic Stroke Types
Predominantly, there are two Ischemic Strokes types. Understanding each is important from the point of view of management of ischemic strokes.
1. Thrombotic Stroke
Thrombotic is the most common ischemic stroke type. It is defined as the Atherosclerotic occlusion of arteries in the head. A thrombotic stroke occurs when blood vessels are clogged with a deposit called plaque. This plaque is usually a collection of cholesterol, fatty deposits, calcium and debris. It collects over the years, often causing no signs and symptoms in the beginning.
As the plaque becomes big enough, it obstructs the flow of blood to the arteries as explained above. Thrombosis is responsible for almost 50% of all stroke cases, which is why management of ischemic strokes resulting from this type is high on the list for doctors and physicians.
Thrombotic Strokes are further divided into two categories:
• Large Vessel Thrombosis: As the name suggests, this ischemic stroke type is characterized by a blockade in the larger vessels like the carotid artery in the neck or those in the middle cerebellum.
• Small Vessel Thrombosis: As the name suggests, this ischemic stroke type is characterised by a blockade in the smaller vessels that are deeper inside the brain. This condition is also referred to as Lacunar Stroke.
2. Embolic Stroke
While management of ischemic strokes resulting from this type is the same as those caused by a thrombosis; there is a stark difference between the onset of both. Embolic Strokes are caused by emboli- clots or cholesterol deposits that do not originate in the brain. These blockades collect elsewhere in the body (usually in the heart) and travel in the blood stream till they reach the brain. Here, they get lodged in the small arteries causing an Embolic Stroke.
The most common cause of the formation of such an embolus is a heart disorder called Atrial Fibrillation.
Transient Ischemic Attack (TIA)
A Transient Ischemic Attack (TIA) is also called a mini stroke. Such a stroke has symptoms similar to those experienced in a regular ischemic stroke, but this one doesn’t last as long. According to medical experts, many patients who experience a TIA do not even know that their brain just suffered some damage because it doesn’t last for more than five minutes.
While the cause and effect is the same, TIA does not leave lasting effects because the brain is able to recover from the sudden shortness of blood, which is often caused by a partially blocked artery. If a TIA is detected, however, management of ischemic stroke becomes easier because doctors and physicians are then able to conduct detailed diagnosis and predict the onset of a full-fledged ischemic stroke.
Pathophysiology Of Ischemic Strokes
As mentioned previously, the sensitive neurons in the brain are prone to instant damage when a blockade hinders the flow of blood. Pathophysiology of ischemic strokes depends on the severity of the ischemia. If the attack is mild, the damage starts on a slow pace. Some neurons start to die when the perfusion is less than 5% but for more than five minutes. However, because of the mildness of the attack it may be six to seven hours till a large section of the brain is affected.
On the other hand, if the ischemia is severe, all affected brain cells may completely pass out in a matter of 30 minutes causing an infraction. Again, management of ischemic stroke comes into play. If blood supply is restored immediately, the damaged caused may not be irreversible. Many parts of the brain may be able to restore function and heal completely over time.
Ischemic stroke recovery times vary depending on the extent of damaged caused in the brain. Patients who have a mild attack have a high chance of a short recovery time compared to patients whose brain function has been severely affected. Ischemic stroke recovery time also depends on the effective management of ischemic strokes.
Signs and Symptoms of Ischemic Strokes
Signs and symptoms appear as a prognosis of ischemic stroke is made. Some of these symptoms may be too painful, others manageable and a lot of others that do not show immediately. When doctors make a prognosis of ischemic strokes, they take into account the appearance of all these symptoms so that further damage can be pre-empted.
In this context, it has been observed that many symptoms of Thrombotic Strokes evolve over a period of 24-48 hours when a patient is at a high risk of stroke. These evolving symptoms result in what is called Unilateral Neurological Dysfunction, i.e. neurological disorder that starts in one point and then spreads out; with many episodes of stability in between.
Depending on which part of the brain is affected, the following signs and symptoms can be recorded:
• Sudden loss of sensation or numbness of the face and limbs. This mostly happens on one side of the body.
• A feeling of distraught and confusion because the brain is unable to make sense of its surroundings.
• Trouble speaking and understanding words. Prognosis of ischemic stroke usually makes this worse, causing slurred speech as well.
• Trouble with vision. If the part of the brain that controls vision is affected, it can lead to black spots and blurred images.
• Sudden and severe headaches that have no particular cause. These are most common in Embolic Strokes and usually absent in unilateral neurological dysfunction.
• Feeling dizzy and unstable. Patients find it hard to walk or carry themselves on their own.
• Seizure activity is also experienced while the stroke occurs and is known to persist even during recovery time of ischemic strokes.
• Impaired consciousness as the brain loses its ability to keep the body fit.
Timely management of ischemic strokes is valuable in making sure that these signs and symptoms do not persist; and if they do, appropriate measures are taken against them.
Risk Factors of Ischemic Strokes
Risk factors help doctors in the management of ischemic strokes. These include:
• Binge drinking
• High blood pressure
• Family history of strokes
• Heart disease
• Sleep apnea
As a caregiver, if you feel that a loved one is experiencing a stroke, use the following signs to make an informed decision.
• Ask the patient to smile. If one side of the mouth droops, it’s a confirmation of a stroke.
• Ask him to raise both arms. If he is unable to raise one arm and it drifts downwards despite trying, call for immediate help.
• Ask him to repeat a sentence you spoke. If speech is slurred and impaired, an ischemic stroke may be the cause.
• Check the timing of symptoms. They may either surface periodically or stay persistently.