Graded Motor imagery-Pain and Weakness

For Complex Regional Pain Syndrome – Type 1, Phantom Limb Pain,
Chronic Pain,  increasing strength in weak limbs even years after
stroke, and distorted motion of Dystonia…
Overview
of
Graded Motor Imagery or Motor Imagery Program

What conditions are helped by Graded Motor Imagery?

Graded Motor Imagery (GMI) has been proven useful for:

• Complex Regional Pain Syndrome – Type 1 — formerly called reflex sympathetic dystrophy  is characterized by pain and skin changes
  that persist long after the tissues associated with the initial injury have healed.
  

•  Phantom Limb Pain – This is pain (or other irritating sensations) that persist long after the limb has been lost.
  

•  Increasing strength of Paretic (partially paralyzed) arms or legs even years after stroke
  

•  Dystonia – Uncoordinated body movements or stuck in a body posture.
  

We thought these conditions were hopeless not long ago.  Now, there is hope!

For Complex Regional Pain Syndrome – Type 1 (CRPS-1) – formerly called reflex sympathetic dystrophy

Stage I – Recognition of Hand Laterality –  for 2 weeks on a daily basis
Studies have shown that this class of patients are slower to recognize(differentiate between left and right) pictures of hands in certain
positions.  This suggests a slower processing in the pre-motor cortex of the brain.  Over the 2 weeks, the difficulty of limb positioning
and the number of repetitions is increased.
Stage II – Imagined Hand Movements –  for 2 weeks on a daily basis
Two(2) times, Imagine that you, smoothly and without pain, move your involved body part into the orientation or position as the one
observed in a displayed picture (specifically chosen to not be painful to imagine).
Stage III – Mirror Movements –  for 2 weeks on a daily basis
The affected limb is placed in a triangular box with a mirror on it so that the patient looking at their affected limb would actually see
their unaffected limb.  They are then instructed to move BOTH their limbs, smoothly and without pain, into the posture observed in a
displayed picture.

How does it work?

The brain reorganizes or adapts.  What we understand now with the special MRI studies (fMRI) and other research is that

          the brain reorganizes in a detrimental way when it is deprived of sensory stimulation it was originally designed to have.  

This reorganization has been best studied in Chronic Regional Pain Syndrome – Type 1(CRPS-1), Phantom Limb Pain, Tinnitus, increasing
strength in weak limbs even years after stroke, and dystonia.

This sensory deprivation and reorganization can be understood with an analogy:

      The area of the brain not receiving sensory stimulation can be thought of as an empty lot in the city.  The empty lot doesn’t just
sit there nice and clean for long.  So what happens to the brain when an area of it is not being stimulated normally?

Another way to phrase this is “How does your brain adapt to the lack of stimulation?”  Lets’ go back to our analogy.

This is a bit tricky to explain, but it is at the root of the cause.  “When the cat is away, the mice will play.“  The  ‘rif-raf’ from around the
neighborhood see the empty lot in the city. 

You have still have good brain tissue, but the nerve endings that used to work are no longer able to transmit the sensation of hearing that
part of the brain is designed to respond to.  The nerves take a couple stops before they get to the part of the brain where we finally
perceive the pain or touch (or other sensation).  This is a picture of the full pathway for sound, and this is a picture of exactly where the
nerves end in the brain.  So, you’ve got good brain and no stimulation, regardless of the sensation.  We don’t know what happens at the
stops along the way (spinal cord, brain stem, thalamus), but we have seen on special MRI images (fMRI) that the brain begins to
reorganize (See the research – European J of Pain(Oct  2009): 13(9),902-907 .)  In fact, in another interesting research study(Rheumatology 200544(4):509-516)   they CAUSED pain in healthy people by creating and mental confusion between what people THOUGHT they were doing with their arm and what they SAW there arm doing.

How does the therapy reorganize the brain?  Essentially, we gradually and systematically redevelop the nerve pathways that normally are activated before and during a movement.  We are exercising the neurons that have not been used. This takes the idle brain tissue and reactivates it.  That is the key.  The stimulation depends upon the sensation involved.  In the case of pain involved with movement, we activate:

• the pre-motor cortex (and likely the parietal lobe) by recognizing a body part oriented in space,
  
• then the primary motor cortex (and likely more portions of the supplementary and premotor cortex) by imagining that our body part is in
  that orientation in space, then
  
• attempt to put our body part in that position in space.
  

The brain tissue that is reactivated in a gradual and purposeful way will not cause pain or other disturbing sensations (itch, cramp, tinnitus).  Oh,
if you could see MY brain now!  The implications for treatment of MANY conditions is amazing and broad.  Anywhere there is lack of sensory
input to normal brain tissue or even a mismatch between sensory input and motor output, this type of treatment will likely be successful.

How did the therapies get developed, tested, and proven?

1. Graded motor imagery is effective for long-standing complex regional pain syndrome: a randomised controlled trial.  Pain, Volume 108,
   Issue 2, Pages 192-198; G.L. Moseley   
   
2. NEUROLOGY 2006;67:2129-2134.  Graded motor imagery for pathologic pain.  G.L. Moseley