August 2014

Cerebrovascular Disease -Stroke

Cerebrovascular Disease -Stroke

 

The brain requires a minimum of 20% of the entire output of fresh oxygenated blood each time the heart beats. It also requires a similar amount of the glucose (blood sugar) that travels within the blood stream. Any disturbances of this blood flow-- even for a few seconds-- can have dramatic and long lasting effects. Paralysis of extremities, loss of speech, loss of use of facial muscles, loss of vision, loss of conscious and even death are all potential end results depending upon the area of the brain involved and the extent of the damage.

Stroke is the name given sudden loss of blood flow to the brain. It is often referred to a CVA or Cerebrovascular Accident. When the blood supply to the brain is suddenly impaired the brain and its cells and tissues are damaged. Stroke is the third-leading cause of death in the United States coming only after heart disease and cancer. More than one-fourth of the neurologically impaired patients in nursing homes are stroke victims.

Most commonly the victims of stroke are elderly people with degeneration of the blood vessels entering into the their brains. However, stroke can also occur in young adults and even children.

Stroke usually comes on suddenly however, there are often a number of symptoms which may occur to as prodromal or heralding symptoms (listed below). It then usually progresses either rapidly or slowly over the next one to two days. During this period, symptoms may come and go, and be irregular or progress steadily to a final conclusion. This period is often referred to as stroke in evolution or the evolution period. When no further deterioration occurs is the stroke considered to be complete. In a few cases' damage may occur in waves over three to ten days and completion may be delayed for up to two or more weeks.

In some cases a sudden stroke is lethal but in most cases the individual survives. In those individuals who do survive there are varying levels of neurologic and psychologic injury. The damage may be slight and hardly noticed or the individual may be rendered completely brain damaged. Interruption of the blood supply to the brain can cause a significant neurologic deficit but on occasion there can be transient interruption of the blood supply with little or no neurologic deficit this is generally referred to as a TIA or Transient Ischemic Attack. Often injuries are permanent but in many cases they are temporary and in time or with physician therapy normal to near normal function can be obtained.

Approximately 300,000 American men and women suffer strokes each year. Nearly 25% of these people will die of their stroke or from its complications. Stroke is the third leading cause of death in our nation and around the world. The risk of stroke literally doubles each decade after the age of 35 years. Statistics show that nearly 5% people over the age of 65 have had at least one stroke.

In recent years the death rate from stroke has declined by nearly 50 percent the reasons given for this include better nutrition, more exercise, and prompt treatment and increased exposure to information leading to preemptive medical care and prevention.

 

Types of Strokes

There are several different types of strokes. These are primarily dependent on "how" and "why" circulation to the brain becomes impaired. There are two main types which we will discuss here. They are Ischemic Stroke and Hemorrhagic Stroke.

 

Factors Leading to Stroke

As in most situations there are risk factors that are controllable and there are factors which cannot easily be changed.

Uncontrollable Factors:

  • Increasing age
  • Gender (more men have strokes)
  • History of a prior stroke
  • Family history of stroke
  •  

    Controllable Factors:

  • High blood pressure-- 70% of all strokes occur in persons with high blood pressure.
  • Atherosclerotic or other forms of heart disease.
  • Valvular heart disease or recent heart attack-- are important precursors
  • Cigarette smoking
  • Elevated cholesterol
  • High red blood cell count
  • Transient Ischemic Attacks (TIAs) or little strokes
  • Women using oral contraceptives tend to have more strokes.
  • Diabetes mellitus, if the diabetes itself can be reasonably well controlled.
  •  

    Men are more at risk at all ages as compared to women. Young women generally are at low risk, however, the risk is significantly increased in women who take birth control pills and who smoke. It is even higher if they do both.

     

    What Are the Symptoms of a Stroke?

    Warning Signs:

  • There may be no warning at all.
  • One or more TIAs should always be considered a warning sign.
  • Recurrent headaches, nausea, dizziness or visual changes may on occasion occur but are often too nondescript
       to definitely indicate that a stroke is coming.
  •  

    Emergency Symptoms:

    Sudden Onset, or Prodromal Signs and Symptoms which occur before the onset of a stroke or at the immediate onset of the stroke:

  • A stroke may be heralded by a mild to incapacitating headaches which may occur gradually or suddenly.
  • Nausea
  • Confusion
  • Sudden numbness or paralysis, complete or partial, involving the face, arms or legs
  • Abrupt loss of consciousness, stupor or coma.
  •  

    Early Signs and Symptoms:

    In the first few hours after a stroke the following may occur:

  • Generalized or specific weakness, numbness, loss of sensation or motor activity involving the limbs of one or both
       sides of the body (hemiplegia) are not unusual findings. This may occur in either the arm or the leg and when both
       upper and lower extremities are involved this will usually occur on the same side of the body with or without
       involvement of the face.
  • Loss of speech or comprehension with or without double vision, slurred speech or difficulty swallowing.
  • Deterioration of speech, vision or sensation over a relatively short period of time (minutes to hours.)
  • Dimness or loss of vision, particularly in one eye
  • Unexplained dizziness, unsteadiness, loss of coordination or sudden falls, nausea or confusion.
  •  

    Later Symptoms:

  • Some strokes are preceded by TIAs, with similar effects that may last anywhere from one minute to several hours.
  • Initially, the paralyzed muscles of a stroke victim are soft because of central nervous system shock, but spasticity
       occurs as spinal motor neurons resume function, tightening muscles and causing the limbs to contract.
  • Loss of urine or defecation
  •  

    How Is the Diagnosis of a Stroke Made?

    The primary diagnosis is made based on the patients past medical history, family history, present signs and symptoms and a complete physical examination. Diagnostic tests may be ordered to confirm or deny the final diagnosis and to determine the extent of damage and injury. Specific tests such as looking for blood in a lumbar puncture (spinal tap), injecting radiopaque dyes into vessels of the neck and head (arteriogram), brain scanning to evaluate for defects in the blood/brain barrier, and performing computerized tomography (see CAT Scan) with image enlargement to search for altered density within the brain are used when needed.

    Often the diagnosis cannot be made immediately, as discussed above the process may need to evolve in order to determine the extent and make a final diagnosis.

     

    Treatment

    Immediate Treatment:

    The initial treatment involves maintaining airway, stopping the internal bleeding, lowering elevated blood pressure, increasing oxygen content of the blood and maintaining life support, if the patient is comatose. This generally requires hospitalization. A brief section on treatment accompanies each of the sections on the two major types of strokes' ischemic and hemorrhagic.

    Once the patient is stabilized and the stroke is complete the role of treatment changes in two directions:

     

    Prevention of another stroke:

    Short Term: This often calls for the use of anticoagulants or aspirin (both are blood thinners) to limit more brain damage and changes in diet, use of hypolipidemic drugs, as well as using drugs to dissolve blood clots in ischemic strokes. It may also include surgery as described for ischemic and hemorrhagic strokes

    Long Term: Physiotherapy becomes the most important part of medical treatment during this stage. The goal is rehabilitation, maximizing and preserving as much motor functions and abilities as are possible. Reducing and preventing contraction of the involved limbs are also critical.

     

    What Does Having A Stroke Mean?

    Without a question having a stroke will change your life. Even if there is no lasting damage, you will not be the same person. It is hard to return to normal knowing that it can happen again. The occurrence of a stroke often changes life for the entire family. This includes the assumption of new roles, as well as the sense of loss and injury that occurs when it happens to a loved one.

    When an area of the brain loses circulation the cells in that area die, this is called and infarct. While a single infarct can cause significant problems, multiple infarcts, which may occur with a series of strokes, can lead to significant loss of intellectual capacity, loss of memory along with all of the other losses discussed above. This is often referred to a Multi-Infarct Dementia.

     

    Treatment is a Team Approach

    The treatment of any stroke victim requires a team approach both involving the medical aspect, short term care, long term care and rehabilitation. This team generally includes an internist, a neurosurgeon, a neurologist, a stroke nurse, a physical therapist, an occupational therapist, and a speech therapist.

    Their overall goal is to limit the extent of damage that can be done, prevent future damage, rehabilitate and help to educate the patient, his or her family in what is needed for long-term care. They must also alert them to problems that may be encountered during rehabilitation and afterwards when the damage is complete and all loses are accounted for.

     

    For Information About Ischemic Strokes, click here.

    For Information About Hemorrhagic Stroke

    For Information About Transient Ischemic Attacks (TIAs)