Pathophysiology for Cerebrovascular Accident

• Cerebrovascular accident is an inadequate blood supply to the brain due to ischemia or hemorrhage with resultant decreased oxygen supply and death of brain cells.
• It may also be classified as a brain attack or stroke.

Etiology: Atherosclerosis, venous thrombosis, embolic and small vessel diseases, hypercoagulopathies, and genetic predisposition.

Precipitating factors: Hypertension, diabetes mellitus, sickle cell disease, obesity, hyperlipidemia, hypercholesterolemia, hypercoagulability, heavy alcohol consumption, smoking, oral contraceptive use, heart disease, physical inactivity, and atrial fibrillation. Nonmodifiable risk factors include African American ethnicity, increasing age, and male gender. Persons with a previous transient ischemic attack (TIA) are at increased risk for developing a CVA.

Signs and Symptoms: Dependent upon which area of the brain affected.
• Right side of brain
—Left side of body is affected.
—Right side of face is affected.
—Vision problem: left homonymous hemianopsia (loss of vision in the left half of the visual field in both eyes)
—Memory loss
—Problems recognizing faces
—Gets lost easily
—Short attention span
—Concrete thinking
—Left hemiplegia
—Left hemiparesis
—Altered sensation on left side
—Impulsive, inquisitive, uninhibited, and socially inappropriate behavior
—Verbal outbursts
—Left-sided neglect of body
—Impaired time and judgment
—Overestimation of own abilities with poor judgment regarding safety
• Left side of brain
—Right side of body is affected
—Left side of face is affected
—Right homonymous hemianopsia (loss of vision in the right half of the visual field in both eyes)
—Memory impaired for verbal and auditory stimuli
—Poor naming ability
—Right hemiplegia
—Right hemiparesis
—Altered sensation on right side
—Speech/language impairment (aphasia): auditory speech interpretation, word selection, and motor aspects (articulation) of speech
—Reading comprehension impaired
—Agraphia (inability to write)
—Slow, cautious behavior
—Easily frustrated
—Disorganized in approach to new problems
—Depression and anxiety
—Impaired comprehension of language and mathematics concepts, difficulty telling left from right

Diagnosis: Usually based on clinical presenting symptoms, client history, and diagnostic tests. A CT is the primary diagnostic tool used to differentiate type of stroke, indicate size and location of the lesion, and guide treatment modality. MRI—to determine extent of brain injury, angiography for carotid artery imaging, transcranial Doppler (TCD)—to measure velocity of blood flow and assess for vasospasm in cerebral arteries. An EEG may be done to show brain wave activity and differentiate hemorrhagic from ischemic stroke. A lumbar puncture may be done if subarachnoid hemorrhage is suspected and CT is not definitive.

Treatment: Determined by type of stroke. Treatment is aimed at restoring blood flow to the brain, preventing further brain damage, and reducing disability.
• Drug therapy
—The following are utilized only for ischemic stroke.
■ Recombinant tissue plasminogen activator (tPA), streptokinase, or urokinase to break down clots.
■ Anticoagulant therapy—warfarin (Coumadin), heparin, or low molecular weight heparin to increase time for blood to coagulate.
■ Acetylsalicylic acid (aspirin), ticlopidine (Ticlid), clopidogrel (Plavix), and dipyridamole (Persantine) to inhibit platelet aggregation.
—Calcium channel blockers—nimodipine (Nimotop) to decrease and/or prevent vasospasm in hemorrhagic stroke.
—Antiseizure medication if seizure has occurred.
—Aspirin or acetaminophen (Tylenol) for treatment of hyperthermia.
• Surgical treatment to remove cerebral hematoma due to hemorrhagic stroke. May include clipping, wrapping, or inserting microcoil in a ruptured cerebral aneurysm.

Nursing Process Elements
• Assess for S&S of progression of disease.
• Cardiac/respiratory assessment and support during acute phase.
• Oral hygiene, swallowing assessment, and assessment for pocketing of food while client is eating.
• Oral and endotracheal suctioning.
• Monitor for aspiration pneumonia; keep head of bed elevated during and after feedings.
• Prevention of deep vein thrombosis—provide range of motion exercises, utilize compression stockings, and assess lower extremities.
• Assist with activities of daily living, turn client every 2 hours, and assist with ambulation. Keep high-top tennis shoes on client’s feet; do not pull on affected limbs.
• Monitor urinary and bowel function.
• Assist family to understand the client’s behavior.
• Assess need for referral for counseling.
• Teach medication administration techniques for home therapy.
• Adaptations of care for left hemisphere damage
—Speak slowly to allow time for processing
—Use simple, short, one- or two-word phrases and commands.
—Gesture and demonstrate along with using words to convey meaning.
—Repeat often.
—Use large print and other visual input.
—Use music to provide information.
—Help family to understand the communication impairment and how to circumvent it; including fact that comprehension is unimpaired.
• Adaptations of care for right hemisphere damage
—Decrease environmental sensory stimuli
—Move and speak slowly around client.
—Use auditory and visual input together to communicate.
—State names of objects as they are touched.
—Break tasks into small steps.
—Orient the client frequently.
—Provide reminders for activities.
—Take precautions in regard to client safety.
—Prepare family members for behavior changes and for inability to recognize faces.

Client teaching for self-care
• Take medication as prescribed.
• Do not discontinue medications abruptly.
• Follow a high-calorie, high-fiber diet and increase fluids to help maintain dietary needs and prevent constipation. Take stool softeners as prescribed and indicated.
• Teach family members/caregivers to speak slowly and give ample time for client to respond. Use communication board as needed.
• Remove clothes from unaffected side first, followed by affected side. Dress affected side before unaffected side.
• Use assistive devices as taught by therapists.
• Continue with exercises taught by physical, occupational, and speech therapy.
• Follow up with home care and rehabilitation team as ordered.
• Remove unnecessary items from table when eating to avoid spills. Use assistive equipment to assist with eating. Allow client to feed self as much as possible.

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