Cerebrovascular Accident (CVA)

• Cerebrovascular alterations involve functional abnormalities in the central nervous system.
• These abnormalities occur when the normal blood supply to the brain is disrupted.

Transient Ischemic Attack (TIA)

• TIA is a temporary episode of neurologic dysfunction stemming from decreased blood supply to the brain.
• It's often referred to as a "little stroke."
• Neurologic deficits typically last less than one hour.
• Manifestations include sudden loss of motor, sensory, or visual function.
• Symptoms arise from temporary ischemia in a specific brain region.
• Brain imaging may not show evidence of ischemia.
• TIAs can be a warning sign of an impending stroke.

Causes of TIA:

• Vascular disorders like aneurysms.
• Blood disorders like hypercoagulation.
• Diminished cardiac output leading to subclavian steal syndrome.

Clinical Manifestations of TIA

• Diminished level of consciousness (LOC)
• Visual problems.
• Vertigo, dizziness, and lightheadedness (fainting).
• Hemiparesis.

Complication of TIA

• Stroke.

Pharmacotherapy for TIA

• Antiplatelets (antiaggregants) to stop platelet formation.
• Examples: Clopidogrel (Plavix), Dipyridamole (Persantine).
• Anticoagulants to prevent blood clot formation.
• Examples: Warfarin, Urokinase.

Major Categories of Strokes

• Ischemic stroke: 88% of cases.
• Hemorrhagic stroke: 12% of cases.

Ischemic Stroke

• It is a CVA or "brain attack" resulting in a sudden loss of function.
• This loss is due to disrupted blood supply to a part of the brain.
• Ischemic strokes diminish oxygen supply in brain tissues.
• It is an urgent healthcare issue similar to a heart attack.
• During a stroke a person typically loses 1.9 million neurons each minute.
• Symptoms depend on the affected brain area.

Major Causes of Ischemic Stroke

• Embolism: A small mass of material circulating in blood vessels.
• Thrombosis: A thrombus or clot, the most common cause.
• Hemorrhage: Rupturing of a blood vessel, usually an artery, within the brain.

Types of Ischemic Stroke

• Large artery thrombotic strokes.
• Small penetrating artery thrombotic strokes affecting the thalamus, basal ganglia, or pons.
• Cardiogenic embolic strokes.
• Cryptogenic strokes with no definite cause.
• Other causes include coagulopathies, MAOIs, and oral contraceptives, sometimes including those impacting blood pressure.

Pathophysiology of Ischemic Stroke

• Obstruction of a blood vessel occurs.
• Cerebral blood flow is disrupted, falling below 25mL/100g of blood per minute.
• Neurons are unable to maintain aerobic respiration, leading to reduced ATP production.
• Mitochondria switch to anaerobic respiration.
• Membranes begin to fail, cells cease to function, and cell death (apoptosis) occurs.

Risk Factors for Ischemic Stroke

• Non-modifiable risk factors:
  • Age over 55.
  • Male gender.
  • African American race.
• Modifiable risk factors:
  • Hypertension.
  • Atrial fibrillation.
  • Hyperlipidemia above 240 mg/dL.
  • Diabetes mellitus.
  • Smoking.
  • Asymptomatic carotid stenosis.
  • Obesity.
  • Excessive alcohol consumption.
  • Lifestyle factors.
  • Arteriosclerosis/atherosclerosis.

Diagnostic Tests for Stroke

• Computed Tomography (CT scan).
• Magnetic Resonance Imaging (MRI).
• Lumbar Puncture.
• Cerebral Angiography.
• Electroencephalogram (EEG).
• Carotid ultrasound.

Clinical Manifestations of Stroke

• Numbness or weakness of the face, arm, or leg, especially on one side of the body.
• Confusion or change in mental status.
• Trouble speaking or understanding speech.
• Visual disturbances.
• Difficulty walking, dizziness, or loss of balance and coordination.
• Sudden severe headache.

Motor Loss in Stroke

• Lesions in the upper motor neuron leading to loss of voluntary control over motor movements.
• Disturbance of voluntary motor control on one side of the body often reflects damage to the upper motor neurons on the opposite side of the brain due to decussation.
• Hemiplegia: paralysis of one side of the body
• Hemiparesis: weakness of one side of the body.

Communication Loss in Stroke

• Aphasia: Impairment or loss of language abilities
• Dysarthria: Difficulty articulating speech.
• Dysphasia: Difficulty in communication
• Apraxia: Inability to perform purposive movements.

Perceptual Disturbances/Sensory Loss in Stroke

• Homonymous hemianopsia.
• Impairment of touch, loss of proprioception, and difficulty in interpreting visual, tactile, & auditory stimuli.
• Agnosia: Inability to recognize things.

Cognitive & Psychological Effects of Stroke

• Impairment in learning capacity, memory, and higher intellectual functions.
• Limited attention span, difficulties in comprehension, forgetfulness, and lack of motivation.
• Depression, emotional lability, hostility, frustration, resentment, and lack of cooperation.

Comparison of Left & Right Hemispheric Strokes

• Left Hemispheric Stroke:
  • Paralysis or weakness on the right side of the body.
  • Right visual field deficit.
  • Aphasia.
  • Altered intellectual ability.
  • Slow, cautious behavior.
• Right Hemispheric Stroke:
  • Paralysis or weakness on the left side of the body.
  • Left visual field deficit.
  • Spatial perceptual deficits.
  • Increased distractibility.
  • Impulsive behavior and poor judgment.
  • Lack of awareness of deficits.

Stroke Prevention

• Primary prevention with a healthy lifestyle.
• Daily exercise.
• DASH diets.

Pharmacotherapy for Stroke

• Warfarin (Coumadin) is used for cardioembolic strokes.
• Platelet-inhibiting medications:
  • Aspirin (ASA).
  • Dipyridamole (Persantine).
  • Clopidogrel (Plavix).
  • Ticlopidine (Ticlid).
• Phenytoin.
• Stool softeners.
• Corticosteroids.
• Analgesics (codeine).

Thrombolytic Therapy for Stroke

• Thrombolytic agents are used to treat ischemic stroke by dissolving the blood clot blocking blood flow to the brain, such as Recombinant t-PA.
• Rapid diagnosis of stroke & initiation of thrombolytic therapy within 3 hours in patients with ischemic stroke leads to a decrease in the size and improve functional outcome after 3 months.
• Bleeding is the most common side effect.

Surgical Interventions for Stroke

• Carotid Endarterectomy: Removal of an atherosclerotic plaque or thrombus from the carotid artery.

Stroke Management

• Complete Physical and Neurologic Examination
• Initial assessment focuses on airway patency.
• Use of osmotic diuretics.
• Elevation of the head of the bed.
• Intubation with an ET tube.
• Administration of supplemental oxygen.
• Continuous hemodynamic monitoring.
• Neurologic assessment.
• Provide restful & quiet environment.
• Stroke rehabilitation.

Nursing Interventions Based on Neurologic Deficit

• Homonymous hemianopsia: Instruct the patient to turn their head in the direction of visual loss; place objects/approach within the intact field of vision.
• Hemiparesis: On the unaffected side of the patient, exercise & increase strength; Place objects within the patient's reach on the non-affected side
• Hemiplegia: Encourage patient to provide ROM exercises to the affected side, maintain body alignment in the functional position
• Ataxia: Support patient during the initial ambulation phase; provide supportive device in ambulation with a walker or cane
• Dysarthria: Provide the patient with alternative methods of communication; Allow the patient sufficient time to respond to verbal communication
• Dysphagia: Before offering foods or fluids test the pt’s pharyngeal reflexes; Allow ample time to eat and place food on the unaffected side of the mouth

Nursing Implications Based on Neurologic Deficit

• Expressive aphasia: Same as for dysarthria.
• Receptive aphasia: Speak slowly & clearly to assist the patients in forming sounds
• Global (mixed): Use gestures & pictures when able; speak clearly & in simple sentences
• Cognitive deficits: Provide familiar objects and reorient patient to time, place and situation frequently
• Emotional deficits: Encourage the patient to express feelings & frustrations in relation to the disease process; Support patient during uncontrollable outbursts, discuss with the family that the outbursts are due to the disease process and provide a safe environment