TIA, CVA, ALS

Nervous System Basics

• The nervous system is divided structurally into two main components:

  • Central Nervous System (CNS): Includes the brain and the spinal cord.

  • Peripheral Nervous System (PNS): Includes the cranial nerves and spinal nerves.

• Functional divisions of the PNS:

  • Somatic Nervous System: Responsible for voluntary actions.

  • Autonomic Nervous System: Responsible for involuntary actions.

• Primary functions controlled by the nervous system:

  • Motor functions.

  • Sensory functions.

  • Autonomic functions.

  • Cognitive functions.

  • Behavioral functions.

• Neuron counts in the system:

  • Approximately $10 \times 10^{6}$ sensory neurons.

  • Approximately $500,000$ motor neurons.

• Basic structure of a neuron:

  • Dendrites.

  • Cell body.

  • Axon.

CNS Pathophysiology and Brain Requirements

• The brain requires a constant and uninterrupted blood flow to provide essential nutrients:

  • Oxygen.

  • Glucose.

• Primary blood supply routes to the brain:

  • Internal carotid arteries: Provides anterior circulation.

  • Vertebral arteries: Provides posterior circulation.

• Physiological consequences of interrupted blood flow:

  • $30\,\text{sec}$: Neurologic metabolism begins to change.

  • $2\,\text{min}$: Neurologic metabolism stops entirely.

  • $5\,\text{min}$: Neuronal cell death occurs.

• Protective mechanisms:

  • Cerebral autoregulation: The mechanism by which the brain maintains constant blood flow despite changes in systemic blood pressure.

Effects of Aging on the Nervous System

• Changes in the Central Nervous System (CNS):

  • Decreased total number of neurons.

  • Reduced cerebral blood flow.

  • Decreased production of Cerebrospinal Fluid (CSF).

• Changes in the Peripheral Nervous System (PNS):

  • Myelin degeneration: Leads to a decrease in nerve conduction velocity.

  • Neuronal death.

  • Decreased overall coordination.

Transient Ischemic Attack (TIA) and Ischemic Events

• Classification of ischemic events (in order of severity/progression):

  • $1$. Transient Ischemic Attack (TIA).

  • $2$. Reversible ischemic neurologic deficit.

  • $3$. Progressive stroke.

  • $4$. Completed stroke.

• Definition of Transient Ischemic Attack (TIA):

  • A temporary focal neurologic deficit resulting from ischemia.

  • Symptoms typically resolve within $1\,\text{hour}$.

• Clinical significance of TIA:

  • It serves as a major warning sign for an impending stroke.

• Etiology:

  • Caused by a temporary blood clot blocking an artery.

• Signs and symptoms of TIA (similar to stroke but transient in nature):

  • Sudden weakness, typically affecting one side of the body.

  • Sudden numbness.

  • Sudden confusion.

  • Trouble speaking or understanding speech.

  • Vision problems.

  • Dizziness and loss of balance.

  • Severe, unexplained headache.

• Diagnostic procedures for TIA:

  • Comprehensive history and neurologic examination.

  • Blood tests.

  • CT scan: Identified as the first priority to rule out hemorrhage.

  • Doppler ultrasound.

  • EKG (Electrocardiogram).

• Medical treatments for TIA:

  • Administration of antiplatelets.

  • Administration of anticoagulants.

  • Surgical or procedural interventions: Possible stent placement or coiling.

• NCLEX Priority Note: A TIA is considered a medical emergency; the healthcare provider must be notified immediately.

Cerebrovascular Accident (CVA / Stroke) Statistics and Types

• Core definition of CVA: Brain ischemia or bleeding leading to neuronal cell death.

• Vital statistics regarding CVA:

  • It is the $3^{rd}$ leading cause of death.

  • Approximately $800,000$ cases occur per year.

  • It is the number $1$ cause of long-term disability.

  • $28\%$ of cases occur in individuals under the age of $65$.

  • Results in approximately $150,000$ deaths per year.

  • $75\%$ of CVA survivors will require long-term care.

  • The risk of stroke doubles every decade after the age of $55$.

• Patient outcomes after CVA:

  • $25\%$ of patients die within $1\,\text{year}$.

  • $50\text{--}70\%$ of survivors achieve independence.

  • $15\text{--}30\%$ of survivors are permanently disabled.

Specific Types of Stroke

• Thrombotic Stroke:

  • Represents the most common type (approximately $60\%$ of cases).

  • Caused by atherosclerosis.

  • Characterized by a gradual onset.

  • Often occurs during sleep.

  • Frequently preceded by a TIA.

• Embolic Stroke:

  • Represents approximately $24\%$ of cases.

  • Occurs when a cardiac clot travels to the brain.

  • Characterized by a sudden onset.

  • Usually occurs during physical activity.

  • High rate of recurrence.

• Hemorrhagic Stroke:

  • Represents approximately $10\%$ of cases but is the most deadly.

  • Caused by bleeding directly into the brain tissue.

  • Hallmark symptom: "The worst headache of my life."

  • Results in a decreased Level of Consciousness (LOC).

  • Rapid progression of symptoms.

  • $30$-day mortality rate: $40\text{--}80\%$

Clinical Manifestations and Stroke Terminology

• General signs and symptoms of CVA:

  • Unilateral weakness or paralysis.

  • Confusion and perceptual disturbances.

  • Difficulty with speech or language.

  • Balance and coordination issues.

  • Severe headache.

  • Facial drooping.

  • Arm weakness.

• F.A.S.T. Assessment Tool (Critical for emergency response):

  • Face: Look for drooping on one side.

  • Arms: Look for weakness or drifting when arms are raised.

  • Speech: Check for slurring or difficulty repeating a simple sentence.

  • Time: Time is brain; call emergency services immediately.

• Specialized Terminology:

  • Hemiplegia: Complete paralysis of one side of the body.

  • Hemiparesis: Weakness on one side of the body.

  • Dysarthria: Slurred or slow speech due to muscle weakness.

  • Aphasia: Loss of ability to understand or express speech.

    • Expressive Aphasia: Difficulty producing language.

    • Receptive Aphasia: Difficulty understanding language.

    • Global Aphasia: Significant impairment in both expression and understanding.

  • Dysphasia: Impaired ability to use or understand language.

  • Hemianopsia: Loss of vision in half of the visual field.

Stroke Risk Factors

• Nonmodifiable Risk Factors:

  • Age (risk doubles after $55$).

  • Gender.

  • Ethnicity.

  • Genetics.

• Modifiable Risk Factors (High-Yield for Testing):

  • Hypertension (HTN): Identified as the biggest modifiable risk factor.

  • Diabetes Mellitus.

  • Smoking.

  • Obesity.

  • Sedentary lifestyle.

  • Hyperlipidemia.

  • Excessive alcohol consumption.

  • Hypercoagulability states.

Laterality: Left-Brain vs. Right-Brain CVA

• Left-Brain Damage:

  • Language problems (aphasia/dysphasia).

  • Behavioral style: Slow and cautious.

  • Physical: Right-sided paralysis (hemiplegia) and right-sided neglect.

• Right-Brain Damage:

  • Behavioral style: Impulsive and prone to safety risks.

  • Spatial and perceptual issues.

  • Physical: Left-sided paralysis (hemiplegia) and left-sided neglect.

Medical Management and Diagnostics

• Diagnostic Tests:

  • CT scan: Must be done first to differentiate between ischemic and hemorrhagic stroke.

  • MRI.

  • Cerebral Angiography.

  • PET scan.

  • Doppler study.

  • Lumbar puncture.

  • EKG.

  • Blood tests.

  • Chest X-ray (CXR).

• Medical Management (Pharmacology and Surgery):

  • Antiplatelets: e.g., Aspirin.

  • Anticoagulants: e.g., Heparin, Warfarin (Coumadin).

  • Surgical intervention: Carotid endarterectomy (CEA) to remove plaque from carotid arteries.

Acute Stroke Management and tPA

• Immediate Clinical Goals:

  • Save the patient's life.

  • Prevent further brain damage.

  • Reduce long-term disability.

• Immediate Nursing Interventions:

  • Elevate Head of Bed (HOB) to $30\text{--}45^{\circ}$.

  • Maintain a patent airway.

  • Activate the stroke team.

  • Maintain NPO (Nothing by mouth) status until a formal swallow evaluation is completed.

• Ongoing Monitoring:

  • NIH Stroke Scale (NIHSS).

  • Frequent neurological checks.

  • Hemodynamic monitoring.

  • Fluid management.

  • Prevention of complications (e.g., DVT, pressure sores).

• tPA (Tissue Plasminogen Activator):

  • Mechanism: Known as a "clot buster."

  • Critical Window: Must be administered within $3\,\text{hours}$ of symptom onset.

  • Contraindication: Never give tPA if the stroke is hemorrhagic.

  • Safety: Monitor closely for systemic or intracranial bleeding.

• Anticoagulation Timeline:

  • Acute Phase: Heparin or tPA.

  • Sub-acute Phase (approx. $3\,\text{months}$): Warfarin.

  • Long-term: Aspirin.

Stroke Prevention and Rehabilitation

• Prevention Strategies:

  • Reduce sodium intake.

  • Maintain healthy weight.

  • Control blood pressure.

  • Regular physical exercise.

  • Smoking cessation.

  • Limit alcohol intake.

  • Diet: Low fat, high in fruits and vegetables.

• Rehabilitation:

  • The most significant improvement typically occurs within the first $6\,\text{weeks}$.

  • Multidisciplinary team: Nurse, Physician, Physical Therapist (PT), Occupational Therapist (OT), Speech-Language Pathologist, Dietitian, and Social Worker.

• Nursing Diagnoses:

  • Impaired respiratory status and risk for aspiration.

  • Impaired physical mobility.

  • Acute/Chronic pain.

  • Self-care (ADL) deficits.

  • Disturbed sensory perception.

  • Urinary/Fecal incontinence.

  • Impaired cognitive function and communication.

  • Risk for impaired skin integrity.

  • Situational low self-esteem.

  • Sexual dysfunction.

Delegation of Tasks

• Registered Nurse (RN) Tasks:

  • Assessing neurological status.

  • Administering high-risk medications (tPA, Heparin).

  • Monitoring cardiovascular changes.

  • Patient and family education.

• Unlicensed Assistive Personnel (UAP) Tasks:

  • Vital signs every $15\,\text{min}$.

  • Measuring Intake and Output (I&O).

  • Repositioning the patient.

  • Performing Range of Motion (ROM) exercises.

  • Implementing seizure precautions.

• Assistive Devices for Recovery:

  • Eating aids (curved utensils).

  • Bathing tools (shower chairs).

  • Dressing aids (button hooks).

  • Mobility aids (walkers, canes).

  • Toileting aids (raised seats).

Amyotrophic Lateral Sclerosis (ALS)

• Overview:

  • A progressive loss of motor neurons.

  • More prevalent in males.

  • Cognition remains intact (the patient remains mentally sharp).

• Key Features:

  • Gradual onset of symptoms.

  • Progressive loss of movement.

  • Affects speech and swallowing.

  • Patient often described as being "trapped in their own body."

• Prognosis:

  • Terminal illness.

  • Survival expectancy: $2\text{--}6\,\text{years}$ post-diagnosis.

  • Leading causes of death: Respiratory failure or aspiration pneumonia.

• Diagnosis:

  • Based purely on clinical symptoms; no definitive diagnostic test exists.

• Management/Interventions:

  • Primarily supportive and palliative.

  • Feeding tubes (PEG) as needed.

  • Mechanical ventilation as needed.

  • Range of Motion (ROM) and frequent positioning.

  • Meticulous skin care.

  • Utilization of assistive devices and communication tools.

  • Scheduling rest periods to manage fatigue.

  • Monitoring swallowing and suctioning as needed.

  • Encouraging fluids and ensuring an upright position during meals.

• Evaluation Goals:

  • Patient remains free from injury.

  • Maintenance of body weight.

  • Absence of pressure sores.

  • Prevention of aspiration pneumonia.

  • Effective use of assistive and communication devices.

  • Emotional expression and use of support systems.

High-Yield Exam Takeaways

• TIA is a warning for a future stroke; treat it as an emergency.

• A CT scan must be the first diagnostic test performed for any suspected stroke.

• tPA has a strict $3\,\text{hour}$ administration window.

• Anticoagulation/tPA is strictly prohibited in cases of hemorrhagic stroke.

• Left-brain CVA results in language deficits.

• Right-brain CVA results in impulsivity.

• Hypertension (HTN) is the single biggest risk factor for stroke development.

• Use the F.A.S.T. acronym for rapid emergency evaluation.