neuro

The Nervous System

Neuro A & P (Review)

• Central Nervous System (CNS)
    - Brain
    - Spinal Cord
• Peripheral Nervous System (PNS)
    - Cranial Nerves
    - Spinal Nerves
    - Autonomic Nervous System
      - Sympathetic (flight or fight)
      - Parasympathetic (rest and digest)

Review of Key Components

• Neurons
• Neuroglial/Glial Cells
• Brain (Review)
• Spinal Cord

Neurotransmitters:

• Epinephrine
• Norepinephrine
• Glutamate
• Serotonin
• Gamma-aminobutyric acid (GABA)
• Dopamine
• Function:
    - Generate impulses
    - Protection
    - Nutritional support
    - Types of effects:
      - Excitatory (↑ likelihood of action potential generation)
      - Inhibitory (↓ likelihood of action potential generation)

Neurological Changes with Aging

Motor/Sensory Changes:

• Decrease in:
    - Vision
    - Hearing
    - Taste
    - Smell
    - Vibration sense
    - Position sense
    - Muscle strength
    - Reaction time
• Related Issues:
    - Motor function is related to sensory function and musculoskeletal (MSK) changes
    - Problems with balance and coordination increase risk for falls

Mental Status Changes:

• Subtle memory changes observed
• More significant changes during infection or disease
• Loss of recent memory or confusion are not considered normal

Assessment of Neurological Function

Health History:

• General details such as appearance, speech, affect, motor function
• Level of function with Activities of Daily Living (ADLs)
• Medications and prior surgeries

Physical Assessment:

• Focus on mental status
• General appearance and behavior
• Cognition: Alert & Oriented (A & O) x 4
• History of mood and affect, and eyes: time, person, place, situation

Mental Status:

• Level of consciousness (LOC)
    - Change in LOC is the first sign of neurological decline!

Cranial Nerve Assessment:

• Not routinely tested unless suspected problem
• Commonly assessed nerves in rapid neurological assessments:
    - Cranial Nerve III (Oculomotor)
    - Cranial Nerve IV (Trochlear)
    - Cranial Nerve VI (Abducens)
• Assessments include:
    - Pupil reaction to light (PERRLA)
    - Direct and consensual response to light
    - Accommodation tests

Rapid Neurological Assessment

Glasgow Coma Scale (GCS):

• Assesses best responses across 3 components:
    - Eye Opening (E):
      - Score of 4: Spontaneous, blinking at baseline
      - Score of 3: Opens to verbal command, speech, or shout
      - Score of 2: Opens to pain (not applied to face)
      - Score of 1: None
    - Verbal Response (V):
      - Score of 5: Oriented
      - Score of 4: Confused conversation; able to answer questions
      - Score of 3: Inappropriate verbal responses
      - Score of 2: Incomprehensible speech
      - Score of 1: None
    - Motor Response (M):
      - Score of 6: Obeys command
      - Score of 5: Purposeful movement to painful stimuli
      - Score of 4: Withdraws from pain
      - Score of 3: Abnormal (spastic) flexion, decorticate posture
      - Score of 2: Extensor (rigid) response, decerebrate posture
      - Score of 1: None
  

Application of Painful Stimuli:

• Assess reflexes, e.g., Extensor Plantar Response (Babinski)
• Normal response: toes point down, abnormal in adults (flexion) indicates neurological issues
• Score of < 3 indicates coma state

Radiologic/Diagnostic Studies

• Cerebrospinal Fluid Analysis:
    - Via lumbar puncture
    - Normal CSF should be clear, colorless, and free of red blood cells (RBCs)
• Imaging Studies:
    - CT Scan
    - MRI
    - PET (positron emission tomography)
    - EEG (electroencephalography)
    - Ultrasound
    - Carotid artery duplex scan
  

Seizure Disorder

Definition:

• Seizure disorder (epilepsy) is characterized by recurring seizures.
• A seizure is a transient, uncontrolled electrical discharge of neurons in the brain that interrupts normal function.

Types of Seizures:

• Generalized Seizures:
    - Involve both cerebral hemispheres.
      - Types include:
        - Tonic-clonic (grand mal)
        - Absence seizures
• Focal (Partial) Seizures:
    - Begin in one part of a cerebral hemisphere.

Causes:

• Mostly unknown; may include:
    - Stroke
    - Brain tumors
    - Central nervous system infections
    - Glucose abnormalities
    - Electrolyte imbalances

Clinical Manifestations:

• Variable symptoms can include:
    - Partial or complete loss of consciousness
    - Tonic (stiff body) and/or clonic (jerking of extremities) phases
    - Postictal phase: muscle soreness, tiredness after seizure episodes.

Diagnostics:

• Based on medical history and EEG results

Management:

• Drug Therapy:
    - Antiseizure medications
• Surgical Therapy
• Safety Precautions:
    - Assess and record details of seizure events
    - Maintain airway patency
    - Do not restrain during a seizure
    - Pad side rails to prevent injury
• Complications:
    - Status epilepticus: seizures lasting more than 5 minutes or recurrent seizures without recovery in between.

Chronic Neurologic Disorders

• Consult handout detailing chronic neurologic disorders, including:
    - Multiple Sclerosis
    - Parkinson Disease
    - Amyotrophic Lateral Sclerosis (ALS)
    - Huntington Disease
    - Alzheimer Disease

Pediatric Neurological Conditions

Cerebral Palsy (CP):

• A non-progressive motor and posture dysfunction caused by CNS insults due to congenital, hypoxic, ischemic, or traumatic origins manifesting from birth to age 2.
• Most common chronic disorder of childhood.

Clinical Manifestations:

• Abnormal muscle tone
• Lack of coordination and spasticity
• Highly variable symptoms based on the origin of the condition, e.g., cord around neck during birth may lead to difficulties in eating and walking.

Management for CP:

• Supportive care includes:
    - Adequate nutrition
    - Maintaining skin integrity
    - Promoting physical mobility
    - Safety, growth, and developmental support
    - Parent education
    - Referrals to community resources, possibly including rehabilitation aids (e.g., wheelchairs)

Guillain-Barre Syndrome (GBS)

Definition:

• An autoimmune process occurring days or weeks after a viral or bacterial infection leading to acute, ascending, rapidly progressive symmetric weakness of limbs.

Manifestations:

• Weakness, paresthesia, hypotonia of limbs, and common pain.
• Most serious complication: Respiratory failure.

Diagnostics:

• Based on history, clinical assessment, and CSF analysis showing elevated protein with normal white cell count (albuminocytologic dissociation).

Management:

• Airway management and respiratory monitoring
• Ventilatory support as needed
• Plasmapheresis: Removes antibodies thought to be responsible for GBS; involves removing plasma and returning blood cells to the patient.
• Pain Management: Important during the initial stages of treatment, usually within the first 2 weeks.

Myasthenia Gravis

Definition:

• An autoimmune disease characterized by a decreased number and effectiveness of acetylcholine receptors at the neuromuscular junction.

Course of Disease:

• Highly variable experiences among patients.

Clinical Manifestations:

• Muscle weakness that worsens throughout the day
• Symptoms may include:
    - Ptosis (drooping eyelids)
    - Dysphagia (difficulty swallowing)
    - Dyspnea (difficulty breathing)
    - Weak voice

Diagnosis:

• Electromyography (EMG)
• Edrophonium Test: Administered IV to provoke temporary improvement in muscle strength, confirming diagnosis

Management:

• Drug Therapy:
    - Anticholinesterase drugs, corticosteroids, and other immunosuppressants.
    - Plasmapheresis and IV immunoglobulin G may be effective.
• Respiratory Support: Critical due to risk of respiratory infection.

Diseases of Cranial Nerves

Bell’s Palsy (Cranial Nerve VII):

• Definition: Unilateral facial paralysis that occurs abruptly.
• Cause: Unknown, most cases are idiopathic.
• Management: Oral corticosteroids and supportive nursing measures; significant recovery occurs in most individuals within 1-6 months.

Stroke

Definition:

• Occurs due to either:
    - Ischemia: Inadequate blood flow to a part of the brain.
    - Hemorrhage: Bleeding into the brain resulting in brain cell death.
• Interruption in oxygen and glucose supply can cause lasting brain damage within minutes.

Risk Factors for Stroke:

Nonmodifiable:

• Age
• Gender
• Ethnicity/Race
• Family History/Heredity

Modifiable:

• Hypertension (HTN)
• Heart Disease
• Diabetes
• Smoking
• Obesity/Metabolic Syndrome
• Lack of exercise
• Drug and alcohol use

Types of Stroke:

• Ischemic Stroke:
    - Subtypes include:
      - Thrombotic: Blood clot at the site forms
      - Embolic: Clot travels from elsewhere (e.g., to cerebral artery)
    - Transient Ischemic Attack (TIA): Temporary neurologic deficits, may resolve within 1 hour, often a warning sign of impending stroke.
• Hemorrhagic Stroke: Results from bleeding into the brain often due to aneurysm or blood vessel rupture.

Stroke Assessment:

• Vital Signs: Monitoring critical
• Neurological Function:
    - Cognitive Changes: Orientation × 4
    - Motor Assessment: Strength and equality of extremities
    - Facial droop, paralysis, and speech issues (expressive/receptive aphasia)

Diagnosis of Stroke:

• Based on medical history and presentation.
• Radiographic Assessment:
    - CT Scan useful for differentiating types of stroke
    - MRI may also provide relevant information
• Laboratory Assessment: Includes CBC, BMP, PT, PTT, and INR assessments.

Stroke - Preventive Therapy

Lifestyle Modifications:

• Healthy diet, weight management, regular physical exercise, smoking cessation, limited alcohol intake, hypertension management

Preventive Drug Therapy:

• Antiplatelet Drugs: First-line treatment for preventing stroke, especially in patients with a history of TIA
    - Includes Aspirin and Coumadin in patients with Atrial Fibrillation (Afib)
• Surgical Prevention:
    - Carotid endarterectomy
    - Angioplasty and stenting as methods to prevent clots and restore arterial flow

BEFAST acronym for Stroke recognition:

• Balance - Loss of balance or coordination
• Eyes - Blurred vision
• Face - Drooping of one side of the face
• Arms - Weakness in an arm or leg
• Speech - Difficulty speaking
• Time - Call for ambulance immediately if symptoms occur

Treatment of Stroke

Drug Therapy for Ischemic Stroke:

• Thrombolytics: Timing is critical, usually administered within 4.5 hours post-symptoms
• Platelet Inhibitors: e.g., Aspirin and Anticoagulants

Endovascular Therapy for Ischemic Stroke:

• Stent Retrievers: Used to remove the blockage in arteries

Treatment for Hemorrhagic Stroke:

• Anti-HTN drugs may be necessary
• Surgical Therapy: Involves management of intracranial bleeding, strategies like evacuation, coiling, or flow diversion to mitigate hemorrhagic complications.

Nursing Interventions

• Frequent neurological checks and monitoring vital signs
• Patient positioning and oxygen therapy management
• Preventing aspiration, managing cerebral edema, and suctioning as necessary.

Increased Intracranial Pressure (IICP)

Definition:

• Caused by the compression of brain tissue due to edema, bleeding, or tumors within the rigid skull structure.

Pathophysiology:

• Cranial insult leads to tissue edema which results in IICP.
• Mechanism:
    - IICP causes compression of the ventricles and blood vessels, leading to decreased cerebral blood flow, reduced oxygen availability with subsequent brain cell death, initiating a cycle of further edema and increasing IICP.

Consequences of Untreated IICP:

• Results in brain herniation and potentially irreversible brain damage; ultimately can be fatal if not addressed.