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Fibromyalgia

Fibromyalgia is a rheumatic disorder characterized by musculoskeletal pain and tender points. Patients report substantial fatigue. They may be depressed, fatigue, mental impairment. Some of them have sleep disturbances and poor cognitive function. Itís differentiated from chronic fatigue syndrome in that these patients universally report pain and have tender points. The etiology of fibromyalgia is unknown. Thereís almost universal reports of cognitive decline in fibromyalgia patients. Long term memory is your ability to remember lists of words over time. And word fluency refers to how rapidly you can produce words from a category like animals or all the letters that begin with f. And they did find deficits in fibromyalgia patients but they concluded that only severely depressed fibromyalgia patients showed these deficits. However, when I looked at their data it seemed that the non-depressed fibromyalgia performed really quite a lot worse than the controls, although not significantly worse.

In terms of what we think is the cause of fibromyalgia, or the etiology. We are not taking a strong position on that. We really believe that itís a chronic disorder that hasnít neuro-chemical mediators but is stress induced. The facilitating stressor could be a physical illness or an injury, or it could be an emotional stressor such as a loss or difficulty that results in a high load situation for the affected individual. And we believe for the vulnerable individual this has neuro-biological consequences.

The relationship among aging cognition and fibromyalgia: as I said, these patients have a lot of memory complaints and I started thinking about fibromyalgia in terms of my work with older adults. Older adults do have reliable memory dysfunction. It appears that in terms of the neurobiology that areas that are particularly sensitive in older adults are the hippocampus and the frontal lobes. Frontal lobes control decision-making executive processing and other control mechanisms for cognitive system. And the hippocampus is more of a storage system for memories. Interesting, the HPA access, which is a neuro-chemical pathway.

So the notion that both fibromyalgia patients and elderly adults have these disturbed HPA access have added some credibility to the notion that perhaps this could be Ö that cognitive aging might be a feasible model for understanding fibromyalgia. So we hypothesized in our initial approach to this problem, that fibromyalgia patients would have the cognitive function.

First we want to document whether or not cognitive function, dysfunction, actually exists in fibromyalgia patients. And we decided to give fibromyalgia patients a battery of tests in areas that are maximally sensitive to aging. Iíll be showing some examples of that. And we decided primarily rather than using sort of cooked-up laboratory tests, to use a lot of neuro-psychological tests that map onto specific brain regions, primarily the frontal lobe and the hippocampus because we thought those were likely sites where the fibromyalgia patients might have problems. Iíll mainly be focusing on these issues today. We are also interested in what factors mediate this dysfunction. Several possibilities include disruption of the HPA access, on sleep disorders, on depression. And we posed the notion that the actual management of pain could drain cognitive resource.

The study Iím going to talk about today Ö Iím going to try to give you a quick overview of the research protocol, because Iíd really like to focus on the data. We had 20 FM patients, and you need to think of these patients as existing in triplets. For instance the triplets being and age-match. For each FM patient we had an age-matched control.

Our primary hypothesis was that FM patients would perform more like older adults than their age-matched controls on many cognitive tasks. And the reason we gave them three blocks of tasks is that patients frequently complain about fatigue and we had the idea that maybe in the first block the patients would look very much like their age-matched controls by the third block.

Let me tell you a little bit about the tasks that we gave these patients, and I do have samples of these as we go along. First we measured speed of processing. This is a very simple task. Iíll show it to you in a moment. But it basically measures how rapidly people can process information and I believe that is a fundamental building block of all cognition that predicts on complex memory function, complex decision-making. Speed of processing is important. It is very easily measured and it is very age-sensitive. And Iíll show you how age-sensitive it is in a moment. Vocabulary is an estimate of world knowledge. You know, we gave people three tasks - synonyms, simple vocabulary and antonyms - that is not age-sensitive. People tend to continue their knowledge across the life-span and it measures their vocabulary and other measures of knowledge.

Okay, what do our participants look like? The median age of the fibromyalgia patients was 47. You can see the older controls are exactly 20 years older and the age-matched controls are within a year of the age of the fibromyalgia patients. These are well-educated participants. The fibromyalgia patients score higher on the geriatric depression scale.

Now Iíd like to turn to the data on cognitive function. The first data that I am going to show you is this speed of processing task. As I mentioned to you, we see speed of processing as fundamental to all of cognition. We take it as almost an overall measure of neuronal integrity, or sort of general neurologic intact-ness. Itís a very simple task. In this particular task subjects are given columns and columns of these items and they are just told to say if these items same or different. On the number of items that they can Ö itís a simple perceptual scanning task.