Stroke: Modifiable risk factors

Stroke | May 14, 2014 | Author: The Super Pharmacist

Brain, Circulatory system, Hypertension, Blood pressure

Stroke: Modifiable risk factors

Stroke is one of the most devastating disorders among cerebrovascular diseases. Two types of stroke, ischemic and hemorrhagic stroke, together with other cerebrovascular anomalies, in 2010 were the cause of approximately 8,300 deaths accounting for 6% of all deaths in Australia. Stroke related deaths are likely to double by the year 2030 as a result of an aging population. Neurologic complications vary in severity and systems effected following a stroke. Stroke accounts for 4% of neurological patients. Stroke is an interruption in the blood supply to the brain, characterised by an abrupt onset of neurologic deficit. This deficit is usually attributable to a focal vascular cause in the brain. It can be either temporary or permanent. The complex structure of the brain is responsible for a wide variety of clinical manifestations of the stroke.

Types of Stroke

It can be classified as:

  • Ischemic: When there is a blood clot that hinders the flow of blood in the vessels. It is the more prevalent type as 85% stroke cases are ischemic in nature. It is also referred to as Transient Ischemic Attack (TIA).
  • Hemorrhagic: When there is a rupture of the blood vessels in the brain. 15% cases of stroke are hemorrhagic in nature.

Disabilities Associated with Stroke

According to National Institute of Health stroke can cause five types of disabilities:

  1. Paralysis or problems controlling movement
  2.  Sensory disturbances including pain
  3.  Problems using or understanding language
  4.  Problems with thinking and memory
  5.  Emotional disturbances

Is Stroke preventable?

Stroke is preventable given that if lifestyle modifications are adopted and related conditions such as Diabetes or Hypertension are effectively controlled, the risk of stroke decreases. Even when a stroke occurs, swift treatment can restore normal health quickly. Understanding the typical signs and symptoms of a stroke can be the difference for surviving a stroke. Signs and symptoms for which you may seek medical attention urgently include:

  • Difficulty in speaking
  • Confusion
  • Problems with walking
  • Sudden weakness or numbness of face, arms or legs
  • Severe headache
  • Vision changes
  • Dizziness
  • Difficulty swallowing
  • Loss of balance & coordination

Every moment counts during a stroke, as the brain is deprived of oxygen, permanent brain damage occurs after short periods of time. The chances of survival and recovery depend upon swift and effective treatment. There are various factors that can help you in prevention of stroke; both modifiable and non-modifiable risk factors exist. Identification of a person’s overall risk and control of modifiable risk factors is the basis for current treatment strategies.

Modifiable or controllable risk factorsCigarrette stub

Hypertension: It is one of the most potent risks of stroke. Maintaining a blood pressure of 130/90mmHg or less is desirable in an average population. People who have developed hypertension should closely monitor their blood pressure and adopt appropriate treatments to safely restore and maintain it.  High blood pressure damages the arteries, putting you at risk for haemorrhages or blockages in the blood vessels supplying your brain

Smoking: Smoking and its noxious chemicals absorbed into the bloodstream can damage blood vessels. This increases the risk of stroke and may lead to hypertension. Nicotine itself raises blood pressure. Carbon monoxide from smoking reduces the amount of oxygen your blood can carry to the brain. Quitting smoking has been proven to reduce the incidence of stroke.

High cholesterol: Increased levels of cholesterol and lipids (hypercholesterolaemia) narrow the blood vessels by causing plaque to form on the inner walls of the blood vessels. This plaque may become dangerous when detached and actively moving within a blood vessel. A clot is formed when this plaque “plugs” a blood vessel, blocking supply of blood beyond that point.

Diabetes: Uncontrolled blood sugar levels has been shown to damage blood vessels, particularly capillaries. It causes destructive changes not only in the body but to the brain as well.

Existing heart conditions: If you are already suffering from a heart disease like atrial fibrillation or coronary artery disease, it puts you at a risk for suffering from stroke. Individualised treatment associated with those conditions can reduce the risk of stroke.

Alcohol: Limiting your alcohol intake to a maximum one drink per day for women and two drinks per day for men significantly lowers your chances of getting a stroke.

Obesity and physical inactivity: A sedentary lifestyle increases the risk of obesity, and a person who is overweight has an increased risk of hypertension, diabetes, cardiovascular complications and stroke among other health complications. Dietary modifications along with exercise help reduce weight and associated stroke risk factors. The most relevant measurement is the waist-to-hip ratio. The World Health Organisation (WHO) defines abdominal obesity as a waist-to-hip ratio above 0.9 for males and 0.86 for females.

Postmenopausal hormone replacement therapy: HRT has reported risk factors associated with the formation of blood clots which may lead to stroke in women.

Sickle cell disease or severe anemia Depression Transient Ischemic Attack: It is a temporary stroke like condition in which a person may have stroke associated symptoms that lasts for few minutes to 24 hours. It usually never causes any permanent disability or damage, however people experiencing these symptoms have a 40% risk of having a stroke. Use of illicit drugs

Non-modifiable risk factors

Age: Adults and children alike; are capable of suffering from stroke. But as we get older, our chances of having stroke increases.

Gender: Men are more prone to having stroke than women. But the women account for more than half of all stroke related deaths.

Race: Indigenous Australians are at a higher risk for developing high blood pressure, obesity and diabetes, putting them at a higher risk for stroke than Caucasians.

Family history: If you have someone in your family who has suffered from stroke or someone who has had a heart attack at an early age, your chances of suffering from a stroke is higher than the rest.

Pregnancy: During and following weeks after delivery, there are increased chances of formation of a clot leading to ischemic stroke. Women suffering from gestational diabetes may also suffer from hemorrhagic stroke.

Other diseases: Abnormal arteries or weak areas in an artery wall, Cancer, chronic kidney disease and some forms of arthritis promote clot formation, therefore increasing the risk of getting a stroke. Prior stroke or heart attack: If someone has had a stroke or a heart attack, chances are higher of having a second stroke.

The Role of Medication in Stroke Prevention

Antiplatelet medications: Anti platelet medications used to prevent and reduce clot formation; for example Aspirin, Dipyridamole and Clopidogrel. High risk patients are recommended to use aspirin as a preventive measure on regular basis. Aspirin, in the long term, may cause abdominal discomfort and sometimes even lead to formation of stomach ulcers. Clopidogrel are safer alternatives to aspirin in terms of gastrointestinal side effects.

Anti-coagulant medications: Medications such as Warfarin are best suited for people who have chronic illnesses like atrial fibrillation or who have already encountered stroke before. Warfarin is an oral anticoagulant that inhibits clot formation leading to blockage of blood vessels. Newer alternatives include rivaroxaban, apixaban and dabigatran. Their advantages include minimal interactions with other drugs when compared to warfarin, improved safety and less monitoring required to assess correct dosing. Rivaroxaban was initially launched to treat deep venous thrombosis (DVT) and pulmonary embolism (PE). Its ability to decrease blood clotting has led to its use for prevention of strokes. Apixaban also act similarly with almost similar results. Dabigatran 150 mg was ranked highest among the treatment options for stroke and systemic embolism prevention.

Thrombolytic medications: In cases of acute stroke where a person is suffering from sudden loss of movement or difficulty in speech Food and Drug administration (FDA) has approved using thrombolytic agents. The most commonly used thrombolytic agent in an emergency situation include streptokinase or streptase and tissue plasminogen activator. The reason they are used short-term only is related to their mechanism of action; it dissolves a clot responsible for blocking a blood vessel, preventing worsening of disabilities and restoring blood flow. They are administered in a hospital setup and are most helpful if given in first three hours of occurrence of symptoms. Another, less potent thrombolytic agent, enoxaparin (Clexane) may be used in a community setting for ongoing treatment or prevention of clotting conditions.

Anti hypertensives medications: Hypertensive is directly related to mortality and morbidity of a patient. Drugs like Calcium channel blockers, Thiazide diuretics, Angiotensin converting Enzyme inhibitors, Beta blockers and Angiotensin II receptor blockers are extremely effective in reducing the incidence of stroke, congestive cardiac failure and renal failure. They lower the blood pressure thereby decreasing the stress on the heart preventing left ventricular hypertrophy and failure. Lipid lowering drugs:

Lipid lowering agents are especially helpful in obese patients and who have diabetes or suffered from angina. Statins, Niacin and Fibrates exhibit multiple functions to decrease the ‘bad’ cholesterol from your body. Lipids are a good predictor for cardiovascular diseases. Better lipid control can lower the stroke incidences.

Some tips to help family and friends cope with a loved one's stroke

Rehabilitation of a stroke patient is geared at reviving skills that are lost due to brain damage. It may be their language skills, mobility or hygiene skills that are lost. “There is a strong consensus among rehabilitation experts that the most important element in any rehabilitation program is carefully directed, well-focused, repetitive practice—the same kind of practice used by all people when they learn a new skill.” Talk with the patient before the appointment about the questions you will ask and be sensitive when asking questions, especially those questions related to stroke complications. Patients may suffer from behavioral changes and alterations of mood. They need to get involved in activities that interest them. It helps them to keep a positive attitude. Joining relevant support groups can help patients to understand their condition better.

References:

Harrison’s Principles of Internal medicine 18th Edition London 2013 http://www.nlm.nih.gov/medlineplus/ency/article/007418.htm Stroke Prevention in Atrial Fibrillation [Internet]. Lopes RD, Crowley MJ, Shah BR, et al. Rockville (MD): Agency for Healthcare Research and Quality (US); 2013 Aug. (Comparative Effectiveness Reviews, No. 123.) http://my.clevelandclinic.org/heart/disorders/carotid/stroke.aspx http://en.wikipedia.org/wiki/Body_mass_index http://my.clevelandclinic.org/disorders/stroke/hic_medications_for_tia-stroke_prevention.aspx http://www.webmd.com/heart/atrial-fibrillation-stroke-11/stroke-causes-risksoved ones are not alone http://www.ninds.nih.gov/disorders/stroke/poststrokerehab.htm U.S. Health in International Perspective: Shorter Lives, Poorer Health. National Research Council (US); Institute of Medicine (US); Woolf SH, Aron L, editors Antithrombotic Agents for the Prevention of Stroke and Systemic Embolism in Patients With Atrial Fibrillation. http://www.ncbi.nlm.nih.gov/books/NBK168990/  

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