Sunday, August 12, 2007

Motor Imagery - what is it all about?

Motor imagery, i.e. visualizing yourself in a particular posture or movement is not new. It has been widely used in stroke rehabilitation. The techniques have had a rebirth with the advent of brain imaging tools such as functional MRI and PET scans. These created an awareness of how changeable and plastic the brain is, as well as how distributed any activity is. The discovery of mirror neurones (Rizzolati and Craighero 2004) in the brain which are active when you watch a person move has also provided a secure base for graded motor imagery studies and clinical use.

The graded motor imagery programme (GMI) as discussed here takes this concept further. It consists of a programme of laterality reconstruction, motor imagery and mirror work and it appears to work better if carried out in that order.



Laterality reconstruction is the restoration of the bodies’ concept of left and right. If you look at another person’s hand and then try and imagine your own hand in that position, can you see that the brain first has to identify if it is a left or right hand. If it can’t then there will be synaptic stress and perhaps more pain and other stress responses. Perhaps removal of the ability bto pick left and right is a clever brain defense to close down motor output. We will discuss this in later blog entries. At NOI, we use two tools to asses and treat laterality deficits – flash cards and the Recognise© programme.

Motor imagery could be broken up into watching an activity, imagining your own body in a static posture or imagining it moving. We will discuss this, including clinical practicalities in the next few weeks.

Mirror therapy is where the brain is tricked into thinking that an affected limb is actually better than it is. Note in the image (insert image), that if the affected limb is “hidden” inside a box with a mirror on one side, use of the good limb will inform the brain, via the reverse image, that the painful and disabled limb can be moved.

While literature such as Moseley’s recent randomized clinical trial in Neurology (Moseley 2006) provides very welcome support for the use of neuromatrix training, the clinical world is always different to the research world. As these blogs progress, we will share clinical experiences, discuss the neuroscience basis of GMI and always link to emerging research.

To conclude for now, to achieve synaptic strength and linkages, activity (including thought) has to be repeated, graded, conquered and context enriched.

Moseley, G. L. (2006). "Graded motor imagery for pathologic pain." Neurology 67: 1-6.

Rizzolati, G. and L. Craighero (2004). "The mirror-neuron system." Annual Review of Neuroscience 27: 169-192.