Sunday, August 23, 2009

An Interesting Case Study: Phantom Limb Pain

A few months ago I read an interesting article, Brain Games, in The New Yorker magazine. A few weeks ago, I saw the author, neuroscientist, VS Ramachandran, give a lecture, On Your Mind, on the fabulous website In both, a featured topic was phantom limb pain.

Phantom limb pain is the sensation of pain emanating from a missing limb that has been either lost in an accident or surgically amputated.
Specifically, Dr. Ramachandran was elaborating on the case of a man (James) whose amputated right forearm felt as if it was tightly and painfully knotted into a clenched fist.
Dr. Ramachandran had the man place his left arm into a mirror box, “visually resurrecting the phantom limb.” Even though James consciously knew it was his left arm in the mirror box, the image in the brain, seeing it as his right arm/hand, was very compelling and convincing. By unclenching the existing left fist in the mirror box, visually it appeared to the brain as though the right fist was unclenching. Using this “visual feedback to trick the brain,” upon unclenching his right fist, James’ pain immediately went away.
At the same time that I saw this, I had a 70 year old female patient enter my office complaining of low back pain. She also reported a 6 year history of ‘hemi-facial spasms.’ Her left eye appeared as though it was constantly, tightly winking. Over the years she had tried multiple medical approaches, including medications and even Botox injections, with no relief.
I excitedly told her about Dr. Ramachandran, James and the mirror box. I suggested that if the mirror could work for a phantom limb, it seemed very likely that it would work for her eye as well. I suggested that she go home and stand in front of a mirror, with her left eye out of the visual field, her good right eye in front of the mirror. Therefore, her brain would see the normal relaxed left eye looking back at her; again, using visual feedback to trick the brain.
She came in a few days later and reported: “as soon as I stood in front of the mirror, I felt my left eye relax.”
While she is by no means ‘cured,’ she now has a useful tool to use to relax her left eye. Now it is a matter of practice, like learning how to ride a bike or play violin, retraining neural networks to a normal relaxed left eye, to overcome 6 years of winking.
This is all small piece of a larger picture: reality, even the reality of your body, your body image, is constructed in your mind.
Note: Dr Ramachandran has a wonderful series on YouTube, Phantoms in the Brain. 3 min/ 13 seconds into Episode 1, Part 2 you can see James and the mirror box.


gramma said...

What a simple magical solution.
It took a BRAIN to figure it out.

Anonymous said...

Ah! Very nice to see a TED ripple effect in action!

Accepting that our mind has such power is quite a remarkable concept to assimilate. Quieting the mind and fasting from so much external stimuli is one way to personally experience our inner capacities.