Study Notes on Transient Ischemic Attack (TIA) and Related Topics

Terms to Know

  • Transient Ischemic Attack (TIA): A temporary blockage of blood flow to the brain.
  • Cerebrovascular Accident (CVA): A condition where blood flow to the brain is stopped either by blockage or rupture; synonymous with stroke.
  • Ischemic Stroke: A type of CVA or stroke caused by a blockage (thrombosis or embolism).
  • Hemorrhagic Stroke: A type of CVA or stroke caused by bleeding into the brain tissue.

Transient Ischemic Attack (TIA)

  • TIA is characterized as a temporary blockage of blood flow to the brain lasting approximately 30-60 minutes.
  • It serves as a significant warning sign of an impending stroke.
  • Generally, damage does not occur with a single TIA; however, recurrent TIAs can lead to cerebrovascular damage.
  • The manifestations of TIA are often indistinguishable from those of a stroke.
  • Symptoms of a TIA usually resolve within 24 hours, underscoring the temporary nature of the condition.

Manifestations of TIA

Vision Symptoms

  • Blurred Vision: Difficulty seeing clearly.
  • Diplopia: Also known as double vision, where a person sees two images of a single object.
  • Blindness in One Eye: Sudden loss of vision in one eye.
  • Tunnel Vision: A loss of peripheral vision, leading to a narrowed field of vision.

Mobility Symptoms

  • Weakness: Generalized weak feeling in the limbs.
  • Facial Droop: Asymmetry in the face where one side appears to droop.
  • Arm or Leg Drift: Affected limb may drift downwards when raised; indicator of motor weakness.
  • Hand Grasp: Reduced ability to grasp items with the affected hand.
  • Ataxia: A disturbance in gait; uncoordinated muscle movements leading to balance issues.

Sensory Symptoms

  • Numbness: Feeling of loss of sensation in the face, hand, arm, or leg.
  • Increased Sensitivity: Inability to differentiate between sharp and dull sensations.
  • Vertigo or Dizziness: A sensation of spinning or loss of balance.

Speech Symptoms

  • Aphasia: Difficulty in producing or comprehending speech.
  • Dysarthria: Slurred or unclear speech that may result from muscle control issues.

Assessments of TIA

  • A complete neurologic exam is crucial for patient assessment.
  • National Institutes of Health Stroke Scale (NIHSS): This scale is essential for evaluating stroke severity and involves certification for its use, although relevant components will be discussed regardless of certification status.
    • A full neurologic examination can be pivotal in confirming complete recovery from a TIA.
    • If a client’s NIHSS results indicate only partial recovery, this may suggest they have had a stroke rather than a TIA.

Laboratory Tests for TIA

Normal Ranges for TIA Lab Tests

  • Hemoglobin: Normal range is 12-18 g/dl.
  • Hematocrit: Normal range is 37%-52%.
  • Platelet Count: Normal range is 150,000 - 400,000 mm³.
  • Partial Thromboplastin Time: Normal range is 30-40 seconds.
  • Prothrombin Time: Normal range is 11-12.5 seconds.
  • International Normalized Ratio (INR): Normal range is 0.8-1.1.
  • Potassium: Normal range is 3.5-5 mEq/L.
  • Sodium: Normal range is 136-145 mEq/L.
  • Useful laboratory tests for TIA include Complete Blood Count (CBC), coagulation times, and electrolyte levels.
    • Note that coagulation times should be interpreted with caution for clients on anticoagulants; anticoagulated clients may have higher coagulation times,
      particularly an INR of 2-3 indicating therapeutic levels.

Radiologic Exam for TIA

  • CT of the Head Without Contrast: Used to visualize potential blockages or harmful structures in the brain.
  • CT Angiography of the Head and Neck: Provides a detailed view of blood vessels; awareness of contrast dye allergies and implications for kidney function is crucial when administering.
  • MRI of the Head: Offers detailed images of brain structures.

EKG Assessments for TIA

  • When evaluating EKG lab results for a TIA client, focus on identifying Atrial Fibrillation.
    • Atrial fibrillation can lead to blood pooling in the atria, resulting in clot formation.
    • Upon the restoration of normal rhythm, these clots may be expelled into the circulatory system, potentially causing myocardial infarction, pulmonary embolism, or stroke.

Nursing Diagnoses and Interventions for TIA

  • Nursing diagnoses may include acute confusion related to hypoxia.
  • Assess the client's readiness for enhanced health management emphasizing wellness in medication, diet, and surgical interventions.
  • For more nuanced diagnoses, reference the Nursing Diagnosis Handbook for comprehensive criteria and planning.