stroke

Examples of stroke in the following topics:

• Other Neurological Disorders

  • Epilepsy and stroke are discussed below.
  • Approximately 75 percent of strokes occur in people older than 65.
  • Risk factors for stroke include high blood pressure, diabetes, high cholesterol, and a family history of stroke.
  • Smoking doubles the risk of stroke.
  • Treatment following a stroke can include blood pressure medication (to prevent future strokes) and (sometimes intense) physical therapy.

• Cerebrovascular Accident

  • The physical disabilities that can result from stroke are varied and depend on the severity of the stroke and the affected areas of the nervous system.
  • High blood pressure is the most important modifiable risk factor of stroke.
  • An ischemic stroke is occasionally treated in a hospital with thrombolysis (also known as a "clot buster"), and some hemorrhagic strokes benefit from neurosurgery.
  • A silent stroke is a stroke that does not have any outward symptoms, and the patients are typically unaware they have suffered a stroke.
  • Conversely, those who have suffered a major stroke are at risk of having silent strokes.

• Case study: using stents to prevent strokes

  • The results of 5 patients are summarized in Table 1.1.Patient outcomes are recorded as "stroke" or "no event", representing whether or not the patient had a stroke at the end of a time period.
  • For instance, to identify the number of patients in the treatment group who had a stroke within 30 days, we look on the left-side of the table at the intersection of the treatment and stroke: 33.
  • Proportion who had a stroke in the treatment (stent) group: 45=224 = 0:20 = 20%.
  • Proportion who had a stroke in the control group: 28=227 = 0:12 = 12%.
  • The proportion of the 224 patients who had a stroke within 365 days: 45 / 224 = 0.20.

• Transient Ischemic Attacks

  • A transient ischemic attack is similar to a stroke; though without permanent damage, it can serve as an important risk factor for stroke.
  • TIAs and strokes cause the same symptoms.
  • Unlike a stroke, the symptoms of a TIA can resolve within a few minutes or 24 hours.
  • Having a TIA is a risk factor for eventually having a stroke or a silent stroke.
  • It is not always immediately possible to tell the difference between a CVA (stroke) and a TIA.

• Aspirin and Thrombolytic Agents

  • Long-term, low dose aspirin therapy is used to help prevent heart attacks, strokes, and blood clot formation in people at high risk of developing them.
  • Primary prevention involves decreasing strokes and heart attacks of people in the general population who have no diagnosed heart or vascular problems.
  • Low doses of aspirin are recommended for the secondary prevention of strokes and heart attacks.
  • In primary prevention trials, aspirin decreased the overall incidence of heart attacks and ischaemic strokes by about one-tenth.
  • In addition, the risks of hemorrhagic strokes and gastrointestinal bleeding offset the benefits of aspirin.

• Medulla Injury

  • Lateral medullary syndrome, also called Wallenberg syndrome and posterior inferior cerebellar artery syndrome, is a disease that presents with a constellation of neurologic symptoms due to injury to the lateral part of the medulla in the brain, resulting in tissue ischemia and necrosis, typically from blood clot (stroke) impeding the vertebral artery and/or the posterior inferior cerebellar artery .
  • Depending on the severity of the blockage caused by the stroke, the hiccups can last for weeks.
  • Long term treatment generally involves the use of antiplatelets like aspirin or clopidogrel and statin regimen for the rest of their lives in order to minimize the risk of another stroke.
  • Other medications may be necessary in order to suppress high blood pressure and other risk factors associated with strokes.
  • The outlook for someone with lateral medullary syndrome depends upon the size and location of the area of the brain stem damaged by the stroke.

• ATP and Muscle Contraction

  • As myosin expends the energy, it moves through the "power stroke," pulling the actin filament toward the M-line.
  • At the end of the power stroke, the myosin is in a low-energy position.
  • After the power stroke, ADP is released, but the cross-bridge formed is still in place.

• Blood Pressure

  • The body regulates blood pressure by changes in response to the cardiac output and stroke volume.
  • It is calculated by multiplying the number of heart contractions that occur per minute (heart rate) times the stroke volume (the volume of blood pumped into the aorta per contraction of the left ventricle).
  • However, cardiac output can also be increased by increasing stroke volume, such as if the heart were to contract with greater strength.
  • Stroke volume can also be increased by speeding blood circulation through the body so that more blood enters the heart between contractions.

• Role of the Cardiovascular Center

  • The cardioaccelerator centres stimulate cardiac function by regulating heart rate and stroke volume via sympathetic stimulation from the cardiac accelerator nerve.
  • The cardioinhibitor centres slow cardiac function by decreasing heart rate and stroke volume via parasympathetic stimulation from the vagus nerve.

• Blood Flow in the Brain

  • Failure of these safeguards results in cerebrovascular accidents, commonly known as strokes.
  • Medical professionals must take steps to maintain proper CBF in patients who have conditions like shock, stroke, and traumatic brain injury.