Fibromyalgia pain isn't all in patients' heads, new brain study finds

[Guest guest]

Dear Friends,

I know that this article is about Fibro (I suffer from that

too), but I thought the subject matter is applicable to RA/OA as well.

~~

Fibromyalgia pain isn't all in patients' heads, new brain study finds

(Posted June 7, 2002)

A new brain-scan study confirms scientifically what fibromyalgia

patients have been telling a skeptical medical community for years:

They're really in pain. In fact, the study finds, people with

fibromyalgia say they feel severe pain, and have measurable pain

signals

in their brains, from a gentle finger squeeze that barely feels

unpleasant to people without the disease. The squeeze's force must be

doubled to cause healthy people to feel the same level of pain - and

their pain signals show up in different brain areas.

Lead authors Gracely, Ph.D., and Dr. Clauw did the

study

at town University Medical Center and the National Institutes of

Health, but are now continuing the work at the University of Michigan

Health System (UMHS). The results, published in the current issue of

Arthritis & Rheumatism, the journal of the American College of

Rheumatology, may offer the proof of fibromyalgia's physical roots

that

many doubtful physicians have sought. It may also open doors for

further

research on the still-unknown causes of the disease, which affects

more

than 2 percent of Americans, mainly women.

To correlate subjective pain sensation with objective views of brain

signals, the researchers used a super-fast form of MRI brain imaging,

called functional MRI or fMRI, on 16 fibromyalgia patients and 16

people

without the disease. As a result, they say, the study offers the first

objective method for corroborating what fibromyalgia patients report

they feel, and what's going on in their brains at the precise moment

they feel it. And, it gives researchers a road map of the areas of the

brain that are most - and least - active when patients feel pain.

" The fMRI technology gave us a unique opportunity to look at the

neurobiology underlying tenderness, which is a hallmark of

fibromyalgia, " says Clauw. " These results, combined with other work

done

by our group and others, have convinced us that some pathologic

process

is making these patients more sensitive. For some reason, still

unknown,

there's a neurobiological amplification of their pain signals. "

In the study, fibromyalgia patients and healthy control subjects had

their brains scanned for more than 10 minutes while a small,

piston-controlled device applied precisely calibrated, rapidly pulsing

pressure to the base of their left thumbnail. The pressures were

varied

over time, using painful and non-painful levels that had been set for

each patient prior to the scan. The study's design gave two

opportunities to compare patients and controls: the pressure levels at

which the pain rating given by patients and control subjects was the

same, and the rating that the two different types of participants gave

when the same level of pressure was applied. The researchers found

that

it only took a mild pressure to produce self-reported feelings of pain

in the fibromyalgia patients, while the control subjects tolerated the

same pressure with little pain.

" In the patients, that same mild pressure also produced measurable

brain

responses in areas that process the sensation of pain, " says

Clauw. " But

the same kind of brain responses weren't seen in control subjects

until

the pressure on their thumb was more than doubled. " In all, the

fibromyalgia patients' brains had both some areas that were activated

in

them but not in controls, and some areas that stayed " quiet " in them

but

became active in the brains of controls feeling the same level of

pain.

This response suggests that patients have enhanced response to pain in

some brain regions, and a diminished response in others, Clauw says.