Cerebrovascular Accident

Diagnosis
1. Two Types of Cerebrovascular Accidents
  1. Hemorrhagic Stroke
    1. Can occur after spine and joint injuries as well
      1. Spinal surgery can lead to dura mater tears, which causes cerebrospinal fluid leakage
        CSF leakage displaces cerebellar, causing stretching and tearing, leading to hemorrhagic stroke
    2. High Mortality Rate
      1. Accounts for 15% of all strokes
      2. But 40% of all stroke deaths are attributed to Hemorrhagic Stroke
    3. Occurs when there is a brain aneurysm or a blood vessel leak
      1. Leakeage of blood into the brain causes swelling and pressure, damaging brain cells and tissue
      2. Two types of Hemorrhagic Stroke
        Intracerebral Hemorrhage (ICH)
        Primary ICH is caused by the spontaneous rupture of small vessels
        Accounts for 78-88% of ICH cases
        Haematoma results from the rupture of an artery, causing extravasation of blood
        Haematoma initiates inflammation, leading to edema and neural damage
        Subsequent clotting results in disruption of the blood brain barrier, leading to cytotoxicity and more edema
        Haematoma can expand because of continued bleeding from ruptured artery
        Expansion distorts and compresses surrounding tissue
        Phagocytosis is used to keep erythrocytes from undergoing cell lysis, and leaking toxic contents into brain tissue
        In ICH, hemolysis occurs, in which the body reponds by releasing Haptoglobin which binds to Hemoglobin to reduce its toxicity and help with phagocytosis
        Cell lysis causes toxicity in red blood cells which forms free radicals
        Leads to oxidative cell damage
        Neutrophils appear, followed by macrophages, initiating phagocytosis of blood products and necrotic tissue
        Secondary ICH is associated with trauma, vascular diseases, tumours, and impaired coagulation
        Subarachnoid Hemorrhage
        Involves bleeding in the subarachnoid space, the area between the pia and arachnoid membranes
        Most often caused by burst aneurysm and trauma
        Also associated with arteriovenous malformation (tangling of blood vessels causing extravasation of blood), bleeding disorders, and use of blood thinners
        Blood in the subarachnoid space causes inflammation of brain tissue (meningitis), which increases intracranial pressure
        Blood from an aneurysm leaks into the cerebrospinal fluid, forming a clot which irritates and damages nearby tissue and brain cells
        Blood blocks CSF circulation, increasing pressure on the brain
        Hydrocephalus
        Fluid buildup enlarges ventricles, causing lethargy, confusion, and incontinence in patient
        Vasospasms
        Blood vessels at base of the brain develops spasms or narrowing, decreasing blood flow to te brain, causing stroke
        Bleeding can cause paralysis, coma, and death
        Accounts for 5% of all strokes
  2. Occurs when there is poor blood flow to an area of the brain
    1. Diagnostic Studies
      1. Magnetic Resonance Imaging (MRI)
        Uses magnets and radio waves to create an image of organs and structures in the body
      2. Echocardiogram
        Determines whether there are blood clots in the heart using sound waves
        Other Diagnostic Tests
        Carotid Doppler
        Ultrasound used to assess blood flow in carotid arteries for narrowing and plaques
        Cerebral Arteriogram
        X-ray images that show narrowing, blockage, or malformations of arteries in the brain
        More accurate than carotid doppler or MRI
        Lumbar Puncture
        Needle is inserted into lower back to obtain a sample of CSF
        Used to diagnose subarachnoid hemorrhages
      3. CAT Scan
        Shows areas of bleeding in the brain using x-rays
  3. Ischemic Stroke
    1. Occurs when there is a loss of blood supply to the brain
    2. Three factors for an ischemic stroke
      1. Embolism
        Blood clot that traveled from another part of the body
      2. Thrombosis
        Blood clot that occurs in the affected artery
        All of these conditions lead to depletion of oxygen and glucose
        ATP production becomes impaired
        Loss of potassium and ATP
        Can cause occlusion and apoptosis
        Inadequate energy impairs ion pump functioning, resuting in an inflow of water
        Causes cytotoxic edema in neurons and glia
        Ischemia stimulates release of excitatory neurotransmitters, glutamate and aspartate
        Neurotransmitters release enzymes which produce free radicals which damage cell membranes and proteins in neurons
        Leads to apoptosis
        Not all Ischemic attacks lead to cell death
        It is possible to reperfuse the ischemic penumbra (area surrounding the core ischemic zone)
        If blood flow is restored early, cells within the core ischemic zone can be saved
      3. Lacunar Infarct
        Artery is blocked because of damage to the arterial wall
    3. Accounts for 85-90% of acute strokes
    4. Extent of damage is dependent on duration, location, and severity of ischemia
Assessment
1. Risk Factors for CVA
  1. Family history of a genetic disorder
    1. Cardioembolic
    2. Large artery disease
      1. Predisposes to prothrombotic state
    3. Hematological disorders
      1. Anemia
      2. Sickle Cell Disease
      3. Antithrombin deficiency
    4. Mitochondrial Diseases
  2. Hypertension
  3. Diabetes
  4. Smoking
    1. Alcohol
      1. Cocaine, Meth, MDMA
  5. Hyperlipidemia
  6. Alpha 1 Antitrypsin Deficiency
2. Signs and Symptoms of CVA
  1. Sudden onset of severe headache
  2. Nausea/ Vomiting
  3. Neck Pain
  4. Loss of consciousness
  5. Seizure
  6. Delirium
  7. Photophobia
  8. Physical Manifestations
    1. BP elevation
    2. Temperature increase
    3. Tachycardia
    4. Papilledema
    5. Retinal Hemorrhage
  9. Numbness, weakness, or paralysis
Treatment
Complications

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Cerebrovascular Accident

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	Erstellt von Ryan Sukdeow vor mehr als 7 Jahre