haven to read the article again closely, but on a quick
first read it seems that
VS Ramachandran's research on Phantom Limbs also employed similar principles...
http://www.csua.berkeley.edu/~reeser/cssa_rama.html
http://www.damaris.org/dcscs/readingroom/2000/phantoms.htm
On 11/1/05, Udhay Shankar N <[EMAIL PROTECTED]> wrote:
http://www.bath.ac.uk/news/articles/releases/candy-mccabe311005.html
Mirrors can trick the brain into recovering from
persistent pain, research suggests
Looking in a mirror at a reflection of their
healthy hand could help people with persistent
pain ease their symptoms and eventually overcome
their problem, say scientists in the latest
edition of the journal Clinical Medicine.
The treatment, being developed by researchers
from the University of Bath and the Royal
National Hospital for Rheumatic Diseases (RNHRD),
is based on a new theory about how people
experience pain even when doctors can find no direct cause.
This 'cortical' model of pain suggests that the
brain's image of the body can become faulty,
resulting in a mismatch between the brain's
movement control systems and its sensory systems,
causing a person to experience pain when they
move a particular hand, foot or limb.
Researchers believe that this kind of problem
could be behind a host of pain-related disorders,
such as complex regional pain syndrome and repetitive strain injury.
In an investigation of whether this system can be
corrected using mirrors to trick the brain,
researchers asked a number of patients with
complex regional pain syndrome (a chronic
debilitating condition affecting 10,000 20,000
patients in the UK at any one time) to carry out
routine exercises in front of a mirror.
More than half experienced pain relief during and
after the exercise and further investigations
showed that even greater improvements can be
achieved if the tasks are practiced beforehand.
"By using a mirror reflection of a normal limb to
convince the brain that everything is alright, we
have found that we can correct this imbalance and
help alleviate pain in complex regional pain
syndrome," said Dr Candy McCabe who works in the
University of Bath's School for Health and the RNHRD.
"We think it is the same system that is triggered
when you are running down stairs, miss the last
step and then feel a jolt of surprise.
"In missing that bottom step, you jar the
prediction that your brain had made about what
was going to happen, triggering an alert to the
body that things are not as you expected, hence the feeling of surprise.
"This is because in most cases normal awareness
and experience of our limbs is often based on the
predicted state rather than the actual state.
"When the two do not match we think sensations
are generated to alert the body that things are
not as it thought rather like an early warning mechanism.
"If the discrepancy is very large [like in the
mirror experiment described below] then pain may
be experienced, as pain is the body's ultimate warning mechanism.
"We think that this system may be responsible for
a range of disorders where patients feel pain for
apparently no clinical reason.
"Somehow the brain's image of the body differs
from what it senses. When the patient moves their
hand, foot or limb, they experience pain as a result.
"This could have important implications for the
therapeutic management of people with chronic pain."
In a separate study published in the journal
Rheumatology earlier this year, researchers from
Bath, Cardiff and Exeter showed that it is
possible to create sensations and feelings in one
limb by looking at a reflection of the other limb in a mirror.
They asked 41 healthy people to sit with a mirror
at right angles in front of them so that they
could only see one side of their body at a time.
The volunteers were then asked to move their
limbs in the same direction at the same time, and
then in opposite directions whilst viewing the mirror reflection of one hand.
Within 20 seconds of starting, more than two
thirds of people involved in the trial reported
some kind of sensation in their hidden limb when
the movement they were seeing in the mirror was
different to what they were feeling in the hidden
hand, for example by moving their hands in different directions.
These sensations included numbness, pins and
needles, a change in temperature and moderate
aching, despite receiving no neural damage to that limb.
"Some people felt pain in their arm after as
little as twenty seconds but not all of our
volunteers experienced these disturbances," said Dr McCabe.
"It would appear that innate susceptibility plays
a part, with some individuals more vulnerable to,
or simply better at detecting, these sensations."
The research is funded by the Arthritis Research Campaign.
The University of Bath is one of the UK's leading
universities, with an international reputation
for quality research and teaching. In 16 subject
areas the University of Bath is rated in the top
ten in the country. View a full list of the
University's press releases: http://www.bath.ac.uk/news/releases
--
((Udhay Shankar N)) ((udhay @ pobox.com)) (( www.digeratus.com))
