neuro

The Nervous System

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

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.