Stroke

Stroke, sometimes also called brain attack, is a medical emergency in which the blood supply to the brain is interrupted, causing a rapidly developing loss of brain function and loss of consciousness. There are many different causes for the interruption of blood supply, and different parts of the brain can be affected. The 2 types of strokes are ischemic stroke, where a blood clot blocks blood flow to the brain, or hemorrhagic stroke, when a blood vessel in the brain bursts, leaking blood into the brain.

Stroke is a possible complication of diabetes, and many other health problems including hypertension (high blood pressure), smoking, heavy consumption of alcoholic drinks, many types of heart disease, obesity, and sedentary lifestyle. Diabetes enhances the risk of stroke. Diabetes can cause both ischemic and hemorrhagic strokes, however, diabetes causes ischemic strokes much more often than hemorrhagic strokes.

Symptoms

The symptoms of a stroke are:

• Drooping in one side of the face
• Weakness or numbness of the arms and legs
• Numbness or paralysis in one side of the body, called hemiplegia.
• Confusion, trouble speaking, and trouble understanding. You can also completely lose the ability to speak from a stroke or a brain hemorrhage.
• Unable to move and walk
• Blindness or other vision problems in one or both eyes
• Deafness in one or both ears
• Dizziness, lightheadedness, and vertigo
• Memory loss
• Problems with attention, balance, and coordination
• Loss of consciousness, including coma
• Nausea or vomiting (usually occurs in hemorrhagic strokes)
• Severe headache (usually occurs in hemorrhagic strokes)
• Seizures (usually occurs in hemorrhagic strokes)
• Difficulty breathing or shortness of breath (when stroke or brain hemorrhage is at the brain stem)
• Dysphagia (swallowing problems) (when stroke or brain hemorrhage is at the brain stem)

Symptoms often start suddenly, and can become dangerous within minutes. Delay of only a few minutes in getting medical support may reduce the chances of recovery or survival.

Causes

The stroke is on account of supply of blood to the brain - either short supply or excess supply. There are two major types of stroke - ischemic stroke and hemorrhagic stroke. In the former too little blood is available to the brain while in the later, the skull get a lot of blood creating a hemorrhage type of situation.

• Ischemic stroke: Ischemic strokes are a type of stroke that occurs when something blocks blood flow to the brain. Ischemic strokes doesn't usually cause headaches, nausea, and seizures.
  • Thrombotic stroke: In thrombotic strokes, fatty, cholesterol-containing deposits build up over time, forming plaques in the heart's arteries, which is called atherosclerosis. If a plaque ruptures, a blood clot can form, causing a stroke.
  • Embolic stroke: An embolus blood clot forms somewhere in the body and travels to the brain. However, it will block blood flow to the brain.

• Hemorrhagic stroke: Hemorrhagic strokes are a type of stroke that occurs when a blood vessel in the brain bursts, leaking blood into the brain. Hemorrhagic strokes causes headaches, nausea, and seizures more often than ischemic strokes.
  • Intracerebral hemorrhage: Intracerebral hemorrhages occur when a blood vessel bursts in the brain itself, leaking blood to the brain.
  • Subarachnoid hemorrhage: Subarachnoid hemorrhages occur when a blood vessel bursts in the spaces that surround the brain, causing bleeding.

Risk factors

There are a number of risk factors contributing to stroke which include the following major risk factors:

• Age: Risk of stroke increases with increasing age.
• Sex: Other things being normal, both men and women are at equal risk of stroke. However, women are slightly more prone to get stroke.
• Race: Some ethnic groups are likely more prone to stroke. For example, Americans of African descents are more likely to be more at risk to stroke largely due to having higher incidence of diabetes and high blood pressure.
• Family history: Family history also plays a role as a risk factor - if one or both parents had stroke, their children are more at risk to get stroke. Likewise, if a brother or sister had a stroke, the chance of getting stroke by the other brother and/ or sister increases.
• High blood pressure: It is a risk factor for stroke, both ischemic and hemorrhagic strokes. High blood pressure (hypertension) weakens and damage blood vessels in and around brain, making them susceptible to atherosclerosis and hemorrhage.
• Cardiovascular disease: A number of cardiovascular diseases including including "congestive heart failure, a previous heart attack, an infection of a heart valve (endocarditis), a particular type of abnormal heart rhythm (atrial fibrillation), aortic or mitral valve disease, valve replacement, or a hole in the upper chambers of the heart known as patent foramen ovale, increases the risk of stroke."
• Undesirable levels of blood cholesterol: High levels of "bad" cholesterol (low-density lipoprotein or LDL) increases the risk of atherosclerosis, a cardiovascular diseasec, which in turn increases the risk of stroke. Further, LDL and other materials build up in the lining of artery walls and harden into plaques. Triglycerides, a blood fat, also increases the risk of atherosclerosis. One or more of these may increase the risk of stroke. However, high levels of high-density lipoprotein (HDL) cholesterol (called "good" cholesterol) reduces the risk of atherosclerosis. HDL helps in removing the cholesterol out of the body through liver.
• Cigarette smoking: It has been proved beyond doubt that cigarette smoking is a major risk factors for stroke and smokers are more prone to stroke than nonsmokers. Nicotine found in tobacco forces the heart to work harder - both heart rate and blood pressure increase, the body is deprived of oxygen as carbon monoxide replaces oxygen in blood and supply of oxygen to the tissues of the brain gets reduces. The combined effect increases the risk of stroke.
• Diabetes: Diabetes is one of the major risk factors for stroke. Diabetes can cause both ischemic and hemorrhagic strokes. Diabetes not only hampers in maintaining a suitable level of blood sugar, it also hampers handling of fat by the body. Persons with diabetes are at a greater risk of high blood pressure, which is itself a risk factor for stroke. Cumulative effect of diabetes related complications increases the chances of developing atherosclerosis and other cardiovascular complications which are risk factors for stroke. *Obesity: Obesity and even being over weight increase the risk of stroke. Excess weight is a risk factor for developing high blood pressure, diabetes, heart disease and other complications, which are risk factors for stroke.
• Previous stroke or TIA: A hitory of previous stroke increases the risk of subsequent stroke. Likewise persons who had a TIA run a higher risk of stroke compared to the persons having no earlier TIA.
• Elevated homocysteine level: Homocysteine, naturally present in the blood build proteins. Persons with elevated having higher levels of homocysteine run a higher risk of stroke.
• Birth control pills & hormone therapy: Studies indicate that women who use birth control pills( particularly if they also smoke and are more than 35 years) are at a higher risk of stroke. Low-dose pills which are currently available carry a lower risk. Similarly, any hormone therapy for menopause increases the risk of stroke.

Prevention

Stroke is largely preventable, with a change in lifestyle and treatment of the medical problems which may cause the condition. Some of the preventive measures include:

• Keeping blood pressure within normal levels: High blood pressure or hypertension is a serious risk factor for stroke, and keeping it within normal ranges is one of the crucial preventive steps to avoid stroke. Regular exercise, learning to manage stress and actually managing stress, having normal weight, controlling and reducing the intake of sodium and alcohol are some of the factors contributing to better control of high blood pressure. For people who have already suffered stroke, keeping blood pressure within normal ranges are more important to avoid a subsequent stroke.
• Cutting down smoking and eventually stopping smoking: Smoking is also a major contributor to stroke. Preventing stroke involves cutting down smoking and ultimately stopping smoking.
• Exercising moderation in alcohol consumption: Interestingly alcohol is a risk factor as also a preventive measure to avoid stroke. Excessive drinking increases the risk of stroke while very moderate drinking is a preventive step.
• Maintaining a physically active lifestyle, and a healthy body weight: Having a physically active lifestyle and healthy body weight are prevent stroke.
• Monitoring blood glucose level: This is an important preventive step as it indicates the level of blood glucose as any indication of high blood glucose level would indicate an immediate requirement to lower the same by use of medicine including insulin and/ or lifestyle changes.

External links

• Stroke - a page from the site of Mayo Clinic