I woke up this morning, like most mornings, and went straight to the bathroom. Although my co-workers probably would suggest the contrary, I do look in the mirror to see how I look before heading off to work. I am relying on my visual sensory system to relay information to my brain. I already know what I look like, but I look anyway. I’m looking to make sure my eyes, ears, nose and mouth are all in place, and in essence, I’m confirming for my brain what I look like.
Richard Gregory is a prominent British neuropsychologist and he estimates that 90% of our visual perception comes from memory, and only 10% from sensory nerve signals. What this means is that if I see a picture of myself with a football helmet covering half of my face, I can still perceive my entire face underneath the helmet, not because my eyes are actually seeing my entire face, but because my memory stores all the features of my face I usually see when I look in the mirror or at a full picture of myself and is able to transpose them onto this partial picture of my face. This probably sounds like a complicated explanation for something we all know – you don’t have to see all of something to perceive it’s detail.
Unfortunately, sometimes this ‘ability’ of our brain can be a detriment. Amputees who experience a phantom limb know this all too well. A phantom limb is the sensation that a limb, which has been removed from the body, is still attached. The individual still experiences all of the usual sensations – itching, sweating, pain…even though they visually observe no limb. Their eyes tell them there is not an arm to be itchy, but their brain is telling them to scratch their arm. Up to 80% of amputees experience phantom limb sensations, the most common being pain.
It used to be thought that the pain was due to irritation in the severed nerve ending, but now the dominant view is that this is another example of neuroplasticity at work. Although the peripheral nervous system may have some impact on phantom limb pain, cortical reorganization is now seen as the major reason some individuals experience pain in a limb that no longer physically exists. Typical drug treatments have little effect. Fortunately, something humans already use can be implemented in any therapy program: a mirror! Mirrors have been used with very good success in controlling the phantom symptoms. Watch this clip from the television drama House in which Dr. House, the main character, helps a patient overcome his phantom limb pain.
Real life isn’t always as dramatic and doesn’t always establish such quick results, but that scene is very realistic. In that example, the amputee is experiencing phantom limb pain that feels like his muscles are clenched in a fist and he is unable to relax them. The mirror “tricks” the brain into perceiving the hand on the affected limb is able to open and relax… The pain instantly disappears. The brain perceives that what was causing the pain (constant muscle contraction) has now been resolved an thus no longer transmits the pain signal.
This scenario will likely require multiple sessions to completely alleviate the phantom pain for good, but this does work for many people. In fact, mirror box therapy has been used successfully in stroke rehabilitation, complex regional pain syndrome, and arm and leg rehab post surgery.
Aim2Walk is in the process of implementing mirror box therapy as yet another tool in our therapy protocol, and we will keep you updated along the way. I am excited at the prospect of a mirror actually working in my favor!
For more information on mirror box therapy, please contact me at email@example.com