Stroke accounts for 1 out of every 15 deaths in the United States. It is the 3rd leading cause of death in most developed countries, and the leading cause of disability in adults. The risk doubles with each decade after age 35. Stroke occurs in men more often than women.

If the flow of blood in an artery supplying the brain is interrrupted for longer than a few seconds, brain cells can die, causing permanent damage. The interruption can be caused by either bleeding or blood clots in the brain.

A very common cause of stroke is atherosclerosis. (See stroke secondary to atherosclerosis.) Fatty deposits and blood platelets collect on the wall of the arteries, forming plaques. Over time, the plaques slowly begin to block the flow of blood. The plaque itself may block the artery enough to cause a stroke.

In some cases, the plaque causes the blood to flow abnormally, which leads to a blood clot. A clot can stay at the site of narrowing and prevent blood flow to all of the smaller arteries it supplies. (This type of clot, which doesn't travel, is called a thrombus.) In other cases, the clot can travel and wedge into a smaller vessel. (A clot that travels is called an embolism.)

Strokes caused by embolism are most commonly caused by heart disorders. An embolism may originate in the aortic arch, especially where there is atherosclerotic plaque. A clot can form elsewhere in the body for any number of reasons, and then travel to the brain, causing a stroke.

Arrhythmias of the heart, such as atrial fibrillation, can be associated with this type of stroke and may contribute to clot formation. Other causes of embolic stroke include endocarditis (an infection of the heart valves), or use of a mechanical heart valve. A clot can form on the valve and break off and travel to the brain.

A second major cause of stroke is bleeding in the brain (hemorrhagic stroke). This can occur when small blood vessels in the brain become weak and burst. Some people have defects in the blood vessels of the brain that makes this more likely. The flow of blood after the break damages brain cells. This kind of stroke can also occur if a clot caused by atherosclerosis or other conditions blocks a vessel, which then breaks and damages surrounding tissue.

See also:

• Stroke secondary to carotid dissection (bleeding from the carotid arteries)
• Stroke secondary to carotid stenosis (narrowing of the carotid arteries)
• Stroke secondary to cocaine
• Stroke secondary to FMD (fibromuscular dysplasia)
• Stroke secondary to syphilis
• Hemorrhagic stroke
• Arteriovenous malformation (AVM)

The risk of stroke is increased by smoking, hypertension, diabetes, hyperlipidemia, and heart disease. Medications that promote clot formation (e.g., birth control pills) may increase the risk, especially if a woman also smokes and is older than 35. Women have a higher risk of stroke during pregnancy and the weeks immediately after pregnancy.

Other illnesses such as vasculitis, lupus or high blood viscosity may contribute to stroke.

The symptoms of stroke depend on how large an area of brain is affected and what part of the brain is injured. In some cases, persons may not be aware that they have had a stroke.

The symptoms of stroke are most commonly a SUDDEN development of the following:

• Loss of movement (paralysis) of any body area
• Weakness
• Decreased sensation
• Numbness
• Tingling or other sensation changes
• Decreased vision
• Language difficulties:
  • slurred, thick, difficult speech
  • inability to speak
  • inability to understand speech
  • may have difficulty with reading or writing
• Inability to recognize or identify sensory stimuli, resulting in "neglect" of one side of the body
• Loss of memory
• Vertigo (abnormal sensation of movement)
• Loss of coordination
• Swallowing difficulties
• Personality changes
• Mood/emotion changes (such as depression or apathy)
• Consciousness changes:
  • sleepy
  • stuporous/somnolent/lethargic
  • comatose/unconscious
  • Unusual or bizarre behavior
• Fainting
• Facial paralysis 'twisted face'
• Eye movements, uncontrollable
• Eye lid drooping
• Drooling

• Head CT or head MRI -- may be used to determine if the stroke was caused by bleeding (hemorrhage) or other lesions and to define the location and extent of the stroke
• ECG (electrocardiogram) -- may be used to diagnose underlying heart disorders
• Echocardiogram -- may be used if the cause is suspected to be cardiac embolus
• Carotid duplex (ultrasound) -- may be used if the cause is suspected to be carotid artery stenosis
• Cerebral (head) arteriography -- may be used if a disorder involving the blood vessels is suspected
• Blood work may be done to exclude immune conditions or abnormal clotting of the blood that can lead to thrombus formation.

A stroke is a medical emergency. Physicians have begun to call it a "brain attack" to stress that getting treatment immediately can save lives and reduce disability due to stroke. Treatment varies, depending on the severity of symptoms. For virtually all strokes, hospitalization is required, possibly including intensive care and life support.

IMMEDIATE TREATMENT
Life support and coma treatment are performed as needed.

tPA is a medicine that breaks up blood clots and can restore blood flow to the affected area. Patients who receive this medicine are more likely to have less long-term impairment. However, there are strict criteria for who can receive tPA -- most important is that the stroke victim be evaluated and treated by a specialized stroke team within 3 hours of onset of symptoms. If the stroke is caused by bleeding rather than clotting, this treatment can make the damage worse -- so time is needed to diagnose the cause before giving treatment.

In other circumstances, blood thinners such as heparin and coumadin are used to maintain circulation and to prevent recurrent strokes. Aspirin and other anti-platelet agents may be used to prevent strokes as well.

Other medications may be needed to control associated symptoms. Analgesics may be needed to control severe headache. Anti-hypertensive medication may be needed to control high blood pressure.

Nutrients and fluids may be necessary, especially if the person has swallowing difficulties. The nutrients and fluids may be given through an intravenous tube (IV) or a feeding tube in the stomach (gastrostomy tube). Swallowing difficulties may be temporary or permanent.

LONG-TERM TREATMENT
The goal is rehabilitation (based on the symptoms) and prevention of future strokes. Rehabilitation includes speech therapy, occupational therapy, physical therapy, positioning, range of motion exercises, and other therapies to prevent complications and promote maximum recovery of function. People should stay active within their physical limitations.

The goal of treatment is to prevent the spread of the stroke and to maximize the patient's ability to function. The recovery time and need for long-term treatment vary.
In some cases, urinary catheterization or bladder/bowel control programs may be necessary to control incontinence.

The individual's safety must be considered. Some people with stroke appear to have no awareness of their surroundings on the affected side. Others show a marked indifference or lack of judgment, which increases the need for safety precautions. For these people, friends and family members should repeatedly reinforce important cues, like name, age, date, time, and where they live to help reduce disorientation.

Communication may require pictures, demonstration, verbal cues or other strategies, depending on the type and extent of language deficit.

In-home care, boarding homes, adult day care, or convalescent homes may be required to provide a safe environment, control aggressive or agitated behavior, and meet physiological needs. Behavior modification may be helpful for some people in controlling unacceptable or dangerous behaviors.

Family counseling may help in coping with the changes required for home care. Visiting nurses or aides, volunteer services, homemakers, adult protective services, and other community resources may be helpful.

Legal advice may be appropriate. Advance directives, power of attorney, and other legal actions may make it easier to make ethical decisions regarding the care of the person with organic brain syndromes such as stroke.

Carotid endarterectomy, removal of plaque from the carotid arteries, may help prevent new strokes from occurring in some people.

Additional support and resources are available from the http://www.strokeassociation.org/American Stroke Association.

The toll-free phone line for stroke survivors and caregivers is 1-888-4STROKE

• Problems due to loss of mobility (joint contractures, pressure sores)
• Permanent loss of movement or sensation of a part of the body
• Bone fractures
• Muscle spasticity
• Permanent loss of cognitive or other brain functions (Multi-infarct dementia)
• Reduced communication or social interaction
• Reduced ability to function or care for self
• Decreased life span
• Side effects of medications
• Aspiration
• Malnutrition

Stroke prevention involves controlling risk factors and treating medical problems that can cause blood clotting:

• Treat high blood pressure, diabetes, heart disease and other associated disorders.
• A low-cholesterol, low-salt diet may be appropriate if the risk factors include atherosclerosis or high blood pressure.
• Reduce or stop smoking.
• Avoid excessive alcohol use.
• Exercise as much as possible.