Neuromuscular Diseases Study Notes

Neuromuscular Diseases

  • Describes conditions that affect muscles (includes arms, legs, heart, and lungs) and nerves controlling muscles.
  • Varied severity, affects individuals differently, and often progressive.
  • Impacts mobility and function, usually leading to disability.
  • Affects all ages (babies, children, adults) and sexes, across ethnic groups.
  • Can be inherited or non-hereditary.

Symptoms

  • Onset: infancy, childhood, or adulthood depending on specific condition.
  • Presenting symptoms may vary:
    • Muscle weakness.
    • Numbness or loss of sensation.
    • Muscle atrophy.
    • Loss of balance and motor control.
    • Breathing and swallowing difficulties.

Specific Neuromuscular Diseases

  • Motor Neuron Disease (MND) - ALS
  • Charcot-Marie Tooth Disease
  • Multiple Sclerosis (covered elsewhere)
  • Guillain-Barre Syndrome

Motor Neuron Disease (MND)

Types:

  • Upper Motor Neuron (UMN): Primary Lateral Sclerosis (PLS).
  • Lower Motor Neuron (LMN): Spinal Muscular Atrophy (SMA), and Progressive Muscular Atrophy.
  • Combination of UMN and LMN: Amyotrophic Lateral Sclerosis (ALS - most common form).

Amyotrophic Lateral Sclerosis (ALS)

  • Fatal neurological disorder; adult-onset (54-67 years).
  • Degeneration of both upper & lower motor neurons leading to:
    • Progressive muscle atrophy.
    • Weakness & paralysis.
    • Consequences: swallowing problems and respiratory issues within 2-4 years of onset (5-10% survive >10 years).

Causes, Diagnosis, Prognosis

  • Cause: unknown, possibly genetic, environmental.
  • Diagnosis: combination of blood tests, MRI, nerve conduction studies, EMG, lumbar puncture, muscle biopsy. Requires evidence of:
    1. LMN degeneration (clinical/electrophysiological/neuropathologic).
    2. UMN degeneration (clinical).
    3. Progressive symptoms.
  • Prognosis varies; usually rapid and progressive deterioration.

Symptoms (UMN and LMN signs)

  • Lower Motor Neuron Signs:
    • Asymmetric weakness; first sign often distal limb weakness.
    • Upper extremity extensors weaker than flexors (leading to postural changes).
    • Bulbar signs: facial muscles weak, difficulty speaking/swallowing, drooling.
  • Upper Motor Neuron Signs:
    • Spasticity, lack of dexterity, loss of strength.
    • Hyperreflexia, positive pathological reflexes (e.g., Babinski's sign).
  • Oculomotor nerves usually spared; bowel and bladder functions intact.

Management of MND

  • Focus on maintaining cardiovascular (CV) endurance, range of motion (ROM), strength, and mobility:
    • Education on safe transfers (for individuals, families).
    • Exercises: ROM, low-resistance strength training, breathing exercises.
    • Stretching: prevent contractures.
    • Mobility aids: equipment and strategies to prevent falls.
    • Pain relief strategies: stretching, massage.

Charcot-Marie Tooth Disease

  • Definition: Hereditary motor and sensory neuropathy.
  • Most common inherited neuromuscular disease.
  • Results in muscle weakness, wasting, and sensory decrease due to degeneration of nerve fibres.
  • Affects mainly adolescents or early adults, can start later.
  • Pathophysiology involves demyelination/resulting low conduction velocities (CMT1) vs. axonal loss (CMT2).

Causes, Symptoms, Diagnosis, Prognosis for CMT

  • Cause: Genetic.
  • Symptoms: Vary based on mutation; common are:
    • Fatigue.
    • Difficulty walking, tripping, clumsiness.
  • Diagnosis: Genetic testing.
  • Prognosis: Non-fatal; most live to normal age and remain active.

Management for CMT

  • Goals: Maintain/improve ability to function; educating on disease progression.
    • Stretching techniques.
    • Strength and ROM exercises.
    • Balance training (e.g., tai chi, yoga).
    • Low-impact aerobic exercises (e.g., walking, swimming).
    • Use of assistive devices.

Multiple Sclerosis & Guillain-Barre Syndrome (GBS)

GBS Overview

  • Autoimmune disorder impacting peripheral sensory systems.
  • Effects include:
    • Temporary inflammation and demyelination; leading to axonal degeneration.
    • Progressive weakness in extremities, sensory loss, autonomic dysfunction.

Capabilities of GBS

  • Occurs typically after bacterial or viral infections.
  • Onset: usually within 2-4 weeks post-infection.
  • Diagnosis based on clinical and electrophysiological studies.
  • Most people recover significantly within weeks to months but may have progressive long-term effects.

Physiotherapy Management for Neuromuscular Diseases

  • Focus on regaining independence, normal movement patterns, improving posture, balance, and coordination:
    • Prevent respiratory issues and lung infections, support joint health, and manage fatigue/pain.
  • Suggested tri-phasic approach for management:
    1. Acute Phase (initial 2-3 weeks): Prevent complications of immobilization (contractures, pressure injuries).
    2. Plateau Phase: Focus on posture and overcoming fatigue.
    3. Recovery Phase (~2-4 weeks): Major focus on weight-bearing and balance exercises, high-intensity rehabilitation.