Harvard Medical School
Contact Us Mission Patient Education Patient Referral Research Services Site Map

Therapy by Diagnosis
Intractable Spasticity

Management of Intractable Spasticity

  • Causes and physiology
  • Assessment
  • Management

Causes and physiology

The components needed for and there function in muscle contraction are:

  1. Alpha motor neuron
    1. The primary nerve providing the contraction stimulus from the spinal cord
  2. Muscle spindles
    1. Involved in sensing muscle tone
    2. Provides feedback to the spinal cord
  3. Gamma motor system
    1. Afferent system providing feedback to the CNS
    2. Involved in regulation of motor contraction
    3. Provides for smooth motion of muscle contraction

When a muscle begins to contract the following must happen:

  • Sensory information from the muscle spindles is transmitted to the spinal cord.
  • These afferent impulses are used to determine the tone present in the muscle and its antagonistic muscle
  • Discharge of the alpha motor neurons occur to the muscle that will contract
  • Muscle contracts
  • Inhibition of antagonistic muscles occur
  • Further enhancement of synergistic motor neurons if needed

This motor neuron control system is under descending inhibitory control by the:

  1. Pyramidal tract
  2. Basal ganglia
  3. Cerebellum

    Spasticity can occur if any of the above neural elements is altered: Cause of spasticity include:

    1. Spinal cord injury
    2. Multiple Sclerosis
    3. Spinal Ischemia
    4. Degenerative myelopathy
    5. Transverse Myelitis
    6. Spinal cord tumor
    7. Cervical Spondylosis
    8. Tropical spastic paraparesis


    Before treatment begins a determination needs to be made if the spasticity that a patient has is:

    1. Good
      1. The patient uses the spasticity for functio
    2. Bad
      1. Spasticity interferes with function
      2. Interferes with sleep
    3. Indifferent
      1. No effect on function
      2. No effect on sleep

    A complete functional assessment should include:

    • ADL's
    • Transfers
    • Pain
    • Bowel and bladder function
    • Talking
    • Sedation from pharmaceutical treatment
    • Mentation
    • Sleep
    • Range of motion
    • Difficulty of nursing care
    • Rehabilitation potential