STROKE

Stroke Symptoms

What Causes a Stroke

Diagnosis

A stroke, or Cerebrovascular accident (CVA), crops up when blood supply to part of the brain is interrupted, leading to the brain cells to die.

There are two major types of stroke.

The first one is known as an ischemic stroke, is caused by a blood clot that obstructs or blocks a blood vessel or artery in the brain. Approximately 80 % of all strokes are ischemic.

The second is called hemorrhagic stroke, is originated by a blood vessel in the brain that ruptures and bleeds into the brain. About 20 % of strokes are hemorrhagic.

In an ischemic stroke, blood supply to a part of the brain is reduced, causing dysfunction of the brain tissue in that part. There are four reasons behind this mal-function of the brain:

1. Thrombosis (obstruction of a blood vessel by a blood clot forming locally)
2. Embolism (obstacle due to an embolus from elsewhere in the body)
3. Systemic hypoperfusion (general decline in blood supply, e.g. in shock)
4. Venous thrombosis.

Cerebral hemorrhage
The most common cause to have bleeding within the brain is unrestrained high blood pressure. Other conditions include aneurysms that leak or rupture or arteriovenous malformations (AVM) in which there is an unusual set of blood vessels that are frail and can bleed.

Blockage of an artery
Lacunar stroke, (lacune=empty space) can happen if the small arteries inside the brain becomes narrow. Obstruction of a single arteriole may affect a petite surface of brain causing that tissue to die (infarct).

Atherosclerosis or hardening of the arteries in the brain is a major cause of Stroke. There are four most important blood vessels that provide the brain with blood. The frontal circulation of the brain that operates nearly all motor, activity, sensation, thought, speech, and emotion is supplied by the carotid arteries.

A stroke is a medical emergency and can cause eternal neurological impairment, complications, and death. It is the prima cause of adult disability in the United States and Europe and it is the number two cause of death worldwide.

Risk factors for stroke –

Advanced age

• Hypertension (high blood pressure)
• Previous stroke or transient ischemic attack (TIA),
• Diabetes
• High cholesterol
• Cigarette smoking
• An Atrial fibrillation.
• High blood pressure is although vital but adjustable risk factor of stroke.

Stroke Symptoms

Signs of a stroke may comprise:

• Abrupt numbness or weakness of the body, particularly on one side.
• Abrupt vision alterations in one or both eyes.
• Abrupt, intense headache with unidentified cause.
• Abrupt problems with dizziness, walking, or balance.
• Abrupt confusion, difficulty speaking or understanding others.

What Causes a Stroke

• A typical cause of stroke is atherosclerosis — hardening of the arteries.
• Plaque is consisted of fat, cholesterol, calcium, and other substances. It is stored in the arteries and left little room for blood to flow. A blood clot may deposit in this limited space and enhances the risk of an ischemic stroke. Atherosclerosis also makes it easier for a clot to form. Hemorrhagic strokes frequently develop from unrestrained high blood pressure that produces a weakened artery to rupture.

Risk Factors: Chronic Conditions
Certain chronic conditions increase your risk of stroke. These include:

• High blood pressure
• High cholesterol
• Diabetes
• Obesity
• Taking measures to manage these conditions can decrease your risk.

Vasculitis
Another unusual reason of stroke is vasculitis, a condition in which the blood vessels become inflamed.

Migraine headache
People with migraine have a small amount of risk of causing stroke. The mechanism for migraine or vascular headaches includes narrowing of the brain blood vessels. Some migraine headache episodes can have common signs of stroke with loss of function of one side of the body or vision or speech difficulties. Generally, the symptoms resolve as the headache resolves.
Risk Factors: Behaviors

• Certain behaviors also increase the risk of stroke:
• Smoking
• Getting too little exercise
• Heavy use of alcohol

Diet

• A poor diet can augment the risk for stroke in a few significant ways.
• Avoid too much fat and cholesterol because they make plaque which can narrow the arteries. Too much salt may increase high blood pressure. And too many calories can lead to obesity.
• A diet comprising of lots of fruits, vegetables, whole grains, and fish may help lower stroke risk.

Risk Factors You Can\’t Control
Some uncontrolled stroke risk factors are –

• Getting older
• Having a family history of strokes
• Gender However, more stroke deaths occur in women
• Race is a significant risk factor. African-Americans, Native Americans, and Alaskan Natives are at greater risk contrast to people of other ethnicities.

Diagnosis

Stroke is diagnosed through different techniques:

• A neurological examination (such as the Nihss),
• CT scans (most frequently without contrast enhancements) or MRI scans,
• Doppler ultrasound and arteriography

The diagnosis of stroke itself is clinical, with support fof the imaging techniques. Imaging techniques also aid in deciding the subtypes and grounds of stroke. There is hardly any necessity of blood test for the stroke diagnosis itself, although blood tests may be of help in finding out the likely cause of stroke.

Physical examination
A physical examination, combining medical history of the symptoms and a neurological status, can clearly depict an assessment of the site and severity of a stroke.

It may give a standard score on e.g. the NIH stroke scale.

Imaging
For diagnosing ischemic stroke in the emergency setting:

CT scans (without contrast enhancements)

• Sensitivity= 16%
• Specificity= 96%

MRI scan

• Sensitivity= 83%
• Specificity= 98%

For diagnosing hemorrhagic stroke in the emergency setting:

CT scans (without contrast enhancements)

• Sensitivity= 89%
• Specificity= 100%

MRI scan

• Sensitivity= 81%
• Specificity= 100%

For detecting chronic hemorrhages, MRI scan is more sensitive.

When a stroke has been diagnosed, diverse other studies may be carried out to determine the underlying etiology. With the current treatment and diagnosis options available, the most important thing is to find out whether there is a marginal source of emboli. Test selection can diverge, since the cause of stroke varies with age, comorbidity and the clinical presentation. Commonly used techniques include:

AN ultrasound/doppler study of the carotid arteries (to detect carotid stenosis) or dissection of the precerebral arteries

AN electrocardiogram (ECG) and echocardiogram (to identify arrhythmias and resultant clots in the heart which may reach to the brain vessels through the bloodstream)

A Holter monitor study to identify intermittent arrhythmias

AN angiogram of the cerebral vasculature (if a bleed is thought to have originated from an aneurysm or arteriovenous malformation) blood tests to substantiate hypercholesterolemia, bleeding diathesis and some unusual causes like homocysteinuria.

Emergency Treatment
For an ischemic stroke, emergency treatment emphasizes on medicine to revive blood flow. A clot-busting medication is highly beneficial at dissolving clots and minimizing prolonged damage, but it must be given within three hours of the inception of symptoms. Hemorrhagic strokes are more difficult to manage. Treatment generally involves attempting to restrict high blood pressure, bleeding, and brain swelling.

Tissue plasminogen activator (TPA)
There is opportunity to use alteplase (TPA) as a clot-buster drug to melt the blood clot that is causing the stroke. There is a narrow window of opportunity to use this drug. The earlier that it is given, the better the result and the less potential for the complication of bleeding into the brain. TPA must be given within three hours after the inception of symptoms. Normally, TPA is injected into a vein in the arm. The time frame for use can be extended to six hours if it is dripped directly into the blood vessel that is blocked.

Heparin and aspirin
Drugs to dissolve the blood (anticoagulation; for example, heparin) are also from time to time used in treating stroke patients in the hopes of improving the patient\’s recovery. It is vague, however, whether the use of anticoagulation overcomes the danger of the current stroke or simply helps to prevent succeeding strokes. In some patients, aspirin given after the onset of a stroke does have a small, but considerable outcome on recovery.

Rehabilitation
Rehabilitation is the most significant thing in the stroke recovery procedure. It helps patients to recover lost skills and learn to compensate for damage that can\’t be undone. The aim is to assist renovate as much independence as possible.

Speech Therapy
For patients who have difficulty in speaking, speech and language therapy is essential. A speech therapist can also assist patients who have trouble swallowing.

Physical Therapy
Usually a stroke triggers muscle weaknesses, as well as balance problems. This can obstruct walking and other daily activities. Physical therapy is an effective way to recover strength, balance, and coordination. For fine motor skills, such as using a knife and fork, writing, and buttoning a shirt, occupational therapy can be beneficial.

Talk Therapy
It\’s general for stroke survivors and their loved ones to undergo a wide range of intense emotions, such as fear, anger, worry, and grief. A psychologist or mental health counselor provides suggestions for dealing with these emotions. A therapist can also observe on the indications of depression, which commonly affects people who are recovering from a stroke.

Stroke Prevention: Lifestyle
People who have had a stroke or TIA can take measures to prevent a recurrence:

• Quit smoking.
• Exercise and maintain a healthy weight.
• Limit alcohol and salt intake.
• Eat a healthier diet with more veggies, fish, and whole grains.

Medications
Doctors often prescribe medications to lower the risk to those who are prone to heart diseases. Anti-platelet medicines, such as aspirin, keep platelets in the blood from sticking together and making clots. Anti-clotting drugs, such as warfarin, may be needed to defend against stroke in some patients. Finally, if you are with high blood pressure, your doctor will prescribe medication to lower it.

Balloon and Stent
A clogged carotid artery can also be treated without major surgery in several cases. The process, called angioplasty, engrosses temporarily inserting a catheter into the artery and inflating a tiny balloon to broaden the area that is narrowed by plaque. A metal tube, called a stent, can be inserted and left in place to keep the artery open.

More than half of people who have a stroke recover the ability to take care of themselves. Those who take clot-busting drugs may recover totally. Therapy encourages those who after a stroke are unable to work independently. While the risk of a second stroke is higher at first, this risk decreases over time.