Care of Patients With Peripheral Nerve & Degenerative Neurologic Disorders

Theory & Clinical Objectives

  • Compare/contrast pathophysiology and complications of:
    • Parkinson disease (PD) vs. Myasthenia gravis (MG)
    • Huntington disease (HD) vs. Amyotrophic lateral sclerosis (ALS)
  • Examine pharmacologic, surgical, and complementary treatments for PD; teach newly-diagnosed patients about medication regimens.
  • Discuss nursing care for patients with PD (mobility, safety, psychosocial, nutrition, aspiration, communication).
  • Explain why Multiple sclerosis (MS) may be difficult to diagnose; outline diagnostic tests.
  • Design nursing care plans:
    • Hospitalized MG patient with respiratory infection.
    • Home-care and self-management plan for MS.
    • Acute, static, and rehab-phase care for Guillain-Barré syndrome (GBS).

Parkinson Disease

  • Etiology & Pathophysiology
    • Degeneration of dopamine-producing neurons in substantia nigra (midbrain).
    • Presence of Lewy bodies (abnormal protein clumps) within remaining neurons.
    • Affects extrapyramidal system—particularly basal ganglia that modulate balance, posture, & coordination.
  • Cardinal Signs & Symptoms
    • Tremor (pill-rolling, improves with purposeful movement).
    • Bradykinesia (slowness of initiation/execution of movement).
    • Rigidity (cog-wheel type; increased resistance to passive movement).
    • Secondary: postural instability, shuffling gait, masklike facies, drooling, dysphagia, micrographia, depression, dementia.
  • Complications
    • Aspiration pneumonia, falls/fractures, skin breakdown, urinary retention/constipation, orthostatic hypotension, medication side-effects (dyskinesias, hallucinations).
  • Treatments
    • Pharmacologic (see Drug Therapy heading).
    • Physical/occupational/speech therapy: strengthen extensor muscles, gait training, adaptive devices.
    • Surgical: deep-brain stimulation, ablation, transplantation of dopamine-producing cells (investigational).
    • Complementary: tai chi, yoga, music & dance therapy (improve balance/coordination).
  • Nursing Care & Patient Teaching
    • Medications: timing critical; "ON–OFF" phenomena explained.
    • Diet: small, frequent, high-calorie/protein; monitor for dysphagia; thickened fluids.
    • Movement: encourage ROM; rock side-to-side before standing; use wide base; elevate chair seats.
    • Sialorrhea: have suction equipment; atropine drops or glycopyrrolate as ordered.
    • Psychosocial: allow extra time for responses, encourage support groups, identify depression.
Drug Therapy (Parkinson)
  • Anticholinergics (↓ ACh to restore ACh–dopamine balance)
  • Dopamine agonists (e.g., pramipexole, ropinirole)
  • MAOI-B\text{MAOI-B} (selegiline, rasagiline) – block dopamine metabolism → ↑ synaptic dopamine.
  • Catechol-O-methyltransferase (COMT) inhibitors (entacapone) – prolong L-dopa\text{L-dopa} half-life.
  • Antivirals (amantadine – ↑ dopamine release).
  • Safety with MAOIs:
    • Avoid high-tyramine foods (aged cheeses, fermented meats, soy sauce, certain beers, Chianti wine) to prevent hypertensive crisis\text{hypertensive crisis}.
    • Contraindicated combination: meperidine + MAOI → hyperpyrexia\text{hyperpyrexia} & possible death.

Multiple Sclerosis

  • Etiology/Pathophysiology
    • Chronic, immune-mediated inflammatory demyelination within CNS.
    • Plaques form → disrupted nerve conduction.
    • Unpredictable, episodic course; multifocal lesions in brain, optic nerves, spinal cord.
  • Clinical Types
    • Relapsing-remitting (most common).
    • Primary progressive.
    • Secondary progressive.
    • Relapsing-progressive.
  • Manifestations
    • Motor: weakness, spasticity, ataxia.
    • Sensory: paresthesias, visual disturbances (optic neuritis, diplopia).
    • Coordination: tremor, dysmetria.
    • Cognitive/emotional: memory loss, impaired judgment, depression.
    • Fatigue (overwhelming; worse in heat).
  • Diagnostic Challenges
    • Symptoms mimic other disorders; require evidence of lesions disseminated in time & space.
    • Tests: MRI (plaques), CSF oligoclonal bands, visual evoked potentials.
  • Treatments
    • Biologic response modifiers (interferon-β, glatiramer acetate) – ↓ relapse frequency.
    • IV methylprednisolone or ACTH for acute exacerbations.
    • Plasmapheresis when steroids ineffective.
    • Autologous stem-cell transplantation (research/selected cases).
  • Nursing Management & Home Care
    • Stress nutrition: adequate fluids & fiber to prevent constipation & UTIs.
    • Energy conservation, cooling strategies.
    • Fall prevention, assistive devices.
    • Bowel/bladder programs; self-catheterization teaching.
    • Address psychosocial impact, employment issues, and support resources.

Amyotrophic Lateral Sclerosis (Lou Gehrig Disease)

  • Etiology/Pathophysiology
    • Progressive degeneration of upper & lower motor neurons (anterior horn, cranial nerve nuclei, motor cortex grey matter).
    • No sensory loss; cognition generally preserved.
  • Manifestations
    • Voluntary muscle weakness → fasciculations, atrophy.
    • Dysarthria, dysphagia; later respiratory insufficiency.
  • Treatment & Prognosis
    • No cure; average survival 2–6 yrs after onset.
    • Riluzole (glutamate antagonist) modestly prolongs life.
    • Non-invasive ventilation (BiPAP) delays need for tracheostomy.
    • Multidisciplinary palliative focus; communication aids.
  • Nursing Considerations
    • Airway clearance, aspiration precautions.
    • Nutrition via PEG if dysphagia worsens.
    • Psychosocial support for patient/family; advance-care planning.

Guillain-Barré Syndrome (Acute Inflammatory Demyelinating Polyneuropathy)

  • Etiology
    • Immune-mediated—often preceded by viral infection (Cytomegalovirus, Epstein-Barr), surgery, vaccination.
  • Pathophysiology
    • Segmental demyelination of peripheral nerves → ascending paralysis.
  • Clinical Course Phases
    • Acute: rapid ascending weakness 24–72 h; may require ventilation.
    • Static: deficits plateau; no further progression.
    • Rehabilitation: remyelination & recovery (weeks–months).
  • Signs & Symptoms
    • Paresthesias, muscle pain, tenderness.
    • Symmetric weakness starting in legs → trunk, arms, cranial nerves.
  • Treatment Goals (Supportive)
    • Maintain ventilation; monitor vital capacity.
    • Manage pain (gabapentin, opioids).
    • Prevent aspiration: elevate HOB, suction, nutrition via enteral route if needed.
    • Communication boards.
    • Plasmapheresis or IVIG (standard of care) accelerate recovery.
  • Nursing Care Plan
    • Frequent neuro & respiratory assessments.
    • DVT prophylaxis due to immobility.
    • PT/OT early to avert contractures and pressure ulcers.

Poliomyelitis & Post-Polio Syndrome

  • Motor neurons in anterior horn, brainstem, frontal lobe affected.
  • Cause: Poliovirus (preventable with Salk/Sabin vaccines).
  • Post-polio: decades later, new muscle weakness & fatigue.
  • Management: lifestyle modifications, energy conservation, orthotics.

Huntington Disease

  • Inherited (autosomal dominant) gene defect on chromosome 4 (expanded CAG repeats).
  • Clinical Features
    • Chorea (involuntary, writhing movements).
    • Cognitive decline → dementia.
    • Emotional disturbances (depression, irritability).
  • Onset: mid-life or later; progressive & fatal (~15–20 yr).
  • No disease-modifying therapy; symptomatic management (antipsychotics for chorea, SSRIs for mood).
  • Genetic counseling critical (50% offspring risk).

Myasthenia Gravis

  • Etiology/Pathophysiology
    • Autoimmune attack (T-cell–dependent) on postsynaptic acetylcholine (ACh) receptors at neuromuscular junction.
    • “Grave muscle weakness.”
  • Manifestations
    • Fluctuating skeletal muscle weakness; worse with exertion, improves with rest.
    • Ocular muscles often first → ptosis, diplopia.
    • Bulbar: dysphagia, dysarthria.
    • Respiratory: risk of myasthenic crisis.
  • Diagnosis
    • Tensilon (edrophonium) test: transient improvement confirms MG.
    • Serum ACh receptor antibodies (positive in ~80%).
    • Electrodiagnostics: repetitive nerve stimulation, single-fiber EMG.
    • Chest CT to assess thymoma.
  • Treatment
    • Anticholinesterase agents (pyridostigmine) inhibit acetylcholinesterase → ↑ ACh at junction.
    • Timing doses 30–45 min before meals optimizes swallowing.
    • Immunomodulation: corticosteroids, azathioprine, mycophenolate.
    • Thymectomy (curative in some, esp. thymoma cases).
    • Plasmapheresis or IVIG for crisis.
  • Nursing Management
    • Monitor respiratory function; incentive spirometry.
    • Prevent myasthenic vs. cholinergic crises; educate on stressor avoidance (infection, surgery).
    • Energy conservation—cluster activities after medication dose.
    • Eye care: artificial tears, eye patches alternating.
    • Support independence; medical alert bracelet.
Myasthenic Crisis Care Plan (Respiratory Infection)
  • Airway & Breathing
    • Assess V/S, negative inspiratory force (NIF), VC; prepare for intubation.
    • Administer oxygen; suction secretions.
  • Medications
    • Hold anticholinesterase initially (risk aspiration) until airway secured.
    • Begin plasmapheresis/IVIG as ordered.
  • Infection Control
    • Broad-spectrum antibiotics per culture.
    • Strict hand hygiene; pulmonary toileting.
  • Nutrition
    • Enteral feeding tube if prolonged intubation.
  • Psychosocial
    • Reassurance, communication boards.

Comparative Highlights

  • Pathophysiology
    • PD: central dopamine deficiency; Lewy bodies.
    • MG: peripheral blockage of ACh receptors (autoimmune);
    • Both lead to motor dysfunction but via different neurotransmitter systems.
  • Complications
    • PD: falls, aspiration due to bradykinesia.
    • MG: respiratory failure during crisis.
  • HD vs. ALS
    • HD has choreiform movements + cognitive decline (autosomal dominant).
    • ALS is pure motor neuron degeneration without cognitive loss.
  • MS Diagnostic Difficulty
    • Variable lesions, relapsing course, multifocal CNS involvement; requires serial imaging & labs.

Ethical & Practical Considerations

  • Progressive neurodegenerative disorders pose choices about feeding tubes, ventilation, advance directives.
  • Genetic implications of HD demand counseling, privacy, discrimination awareness.
  • Access to high-cost biologics (MS, PD deep-brain stimulation) raises healthcare equity questions.