Cerebrovascular Accidents (CVAs) and Strokes

Strokes and Cerebrovascular Accidents (CVAs)

Overview

  • Strokes involve a sudden decrease in blood flow to the brain.
  • Usually localized but can affect larger areas with major artery occlusions.
  • Time is critical in managing strokes.

Incidence and Risk Factors

  • Incidence: Strokes are the primary cerebrovascular disorder.
  • Cost: Very expensive due to hospitalization, rehab, and follow-up care.
  • Risk Factors: Modifiable and non-modifiable factors.
Modifiable Risk Factors
  • Diet and exercise.
  • Management of comorbidities (e.g., heart disease, hypertension).
Non-Modifiable Risk Factors
  • Race and gender: Men have higher risk until menopause when women's risk evens out due to hormonal changes.
  • Race: Japanese, Latino, and African American individuals are at higher risk.

Types of Strokes

  • Large Artery Thrombotic: Occur in large arteries.
  • Small Penetrating: Deeper in brain tissue, harder to reach.
  • Cardiogenic: Originate in the heart (e.g., due to atrial fibrillation (AFib)).
  • Other: Caused by cocaine (vasospasms), coagulopathies, or arteriovenous malformations (AVMs, birth defects).

Pathophysiology

Blood Loss
  • Hemorrhagic stroke: Bleeding into the brain, leading to loss of perfusion.
Blockage
  • Ischemic stroke: Emboli block arteries (e.g., from AFib).
  • Both types result in reduced blood flow and oxygen to cells, leading to ischemia and necrosis.
Time Sensitivity
  • Rapid response is crucial to save the penumbra (area around the primary damage).
  • The goal is to minimize the oxidative process, calcium influx, and glucose release that cause further damage.

Ischemic Strokes vs. TIAs

Ischemic Strokes
  • Caused by blood clots or plaque/stenosis.
  • Transient Ischemic Attacks (TIAs): Mimic ischemic strokes but resolve within 24 hours.
  • TIAs are warning signs; one-third of patients with TIAs will have a stroke within a year.
  • Most strokes (90%) are ischemic.
Thrombotic Strokes
  • Caused by fat or plaque, often occur during sleep due to relaxation.
  • Progress slowly over 2-3 days as blood flow gradually decreases.
  • Platelets adhere to plaque, causing backup.

Signs and Symptoms

  • Depend on the affected brain area.
  • Common signs: Numbness/weakness (face, one-sided), visual changes, speech changes.
    Example: Right-Sided Stroke
    Visual and spatial issues.
    Example: Left-Sided Stroke
    Speech changes (aphasia), using incorrect words, difficulty understanding.
Manifestations

*Motor, Communication, Perception:
Visual changes.

  • Sensory and Cognitive Changes: Increased risk of depression due to loss of independence, communication changes, and loss of bladder control.
Brainstem Issues
  • May resemble spinal cord injuries, affecting breathing and body temperature.

Hemorrhagic Strokes

Types:

Subarachnoid, epidural, subdural.

Mechanism

Blood vessel ruptures, causing blood to seep into tissues, leading to spasms.

Causes:(80%)
  • High blood pressure.
  • Ruptured artery walls, tumors, AVMs, anticoagulants, and blood disorders.
Management
  • Manage increased intracranial pressure (ICP).
  • High morbidity (around 50%) and longer recovery.
  • Surgical interventions: Burr holes, craniotomy (for epidural/subdural bleeds).
Stroke Location
  • MCA (Middle Cerebral Artery) vs. ICA (Internal Carotid Artery) strokes.
  • ICA strokes cause more damage as they affect a larger area.
Manifestations:

Similar to ischemic strokes, plus headaches, seizures, and ICP-related symptoms. Hypertension.

Pathophysiology of Hemorrhagic Strokes
  • Increased ICP, decreased cerebral blood flow, vasospasms.
  • Hypertension: Body compensates for decreased oxygenated blood to the brain.
  • Permissive Hypertension: Allowing higher blood pressure (e.g., 170s-180s) for the first 24 hours to increase perfusion.

Assessment and Diagnosis

B.E.F.A.S.T.

Acronym for stroke recognition:
Balance, Eyes, Face, Arms, Speech, Time.

  • Balance: Sudden loss of balance.
  • Eyes: Vision changes
  • Face: Facial drooping.
  • Arms: Arm weakness.
  • Speech: Slurred or difficult speech.
  • Time: Act fast.
Assessment

Determine the last time the patient was seen well to evaluate for tPA eligibility.

Neurological Assessment
  • NIHSS (National Institutes of Health Stroke Scale) in addition to GCS (Glasgow Coma Scale) to evaluate loss.
  • Assess airway, gag reflex, and swallowing ability (NPO until evaluated)
  • Health History: Evaluate comorbidities.
  • Assessments: Speech, visual changes, swallowing, bowel function, NIHSS scales.
Diagnostics
  • Non-contrast CT scan within 20 minutes of arrival to rule out bleeding.

Management

Goals of Care

Prevent secondary issues and dissolve clots (if present).

Thrombolytic Therapy (tPA)
  • tPA Eligibility Criteria (example: Queen of the Valley policy):
    *Ischemic stroke within 3 hours of onset (up to 4.5 hours for select patients).
    Patient > 18 years old.
    *Clinical diagnosis of acute ischemic stroke with measurable neurological deficit.
    *Head CT without evidence of hemorrhage.
    *NIHSS ≤ 25.
    *Patient not taking Coumadin.
  • tPA Exclusion Criteria examplesRecent intracranial/intraspinal surgeries, serious head trauma, or stroke. Known history of intracranial hemorrhage, platelet count < 100,000, hematocrit < 25, glucose < 50 or > 400.
  • Always check facility-specific policies.
Surgical Options (Hemorrhagic Strokes)

*Burr holes, craniotomy to prevent bleeding complications and manage ICP.

  • Manage pain and fever to decrease body workload.
  • Ventilator support may be needed.

Patient Education

Management and Prevention
  • Blood pressure medications.
  • Antiplatelets (e.g., baby aspirin).
Post-Stroke Medications
  • tPA (if eligible), Lovenox/Heparin injections, steroids (reduce inflammation).
  • Anticonvulsants to prevent seizures (especially in hemorrhagic strokes).
Rehabilitation
  • Early mobilization is key.
  • Physical, speech, and occupational therapy.
  • Address shoulder pain and prevent overstretching.
  • Reposition patients to prevent pressure ulcers.
Education for Patients and Families
  • Include family in education.
  • Discuss community support, realistic goals, and expectations.
  • Educate on causes, prevention, and the rehab process. Patient may not ever be independent again.