Effect of Temperature on Pain and Brown Adipose Activity in Fibromyalgia

The pathophysiology of pain related to fibromyalgia is not understood. This condition is
difficult to diagnose and to treat. One clue may be that tender points (areas which hurt
typical of fibromyalgia) are most densely located near the clavicles. This is also the area
where brown fat is located in humans. Brown fat is typically used to maintain body
temperature. Stress (such as cool temperature or special diets, i.e., high fat, low
carbohydrate) appears to worsen the pain seen in fibromyalgia. We hypothesize that a
mechanism for pain in this disease relates to activating brown fat through neural
mechanisms. The nerves to brown fat also go into adjacent muscle and skin. So, when brown
fat is turned on or increases in amount, collateral nerves may cause pain at the tender
points.

The central hypothesis is that stress such as temperature or diet will activate brown fat.
Patients with fibromyalgia will have greater activation or volume of brown fat. Neuralgia
related to stress may be the etiology of the pain. If this hypothesis is proven, there are
several drugs on the market that could be deployed to correct these patients' problems.
Therefore, this project, if successful, will lead to clinical trials of these drugs in
fibromyalgia patients.

The initial study phase will involve five subjects - one healthy volunteer and four women
with fibromyalgia. These five subjects will each have one visit that will include several
hours in both the warm room and the cold room. Nociceptive flexion reflex (NFR) testing will
be conducted while they are in each of the temperature-controlled rooms. We anticipate
conducting the initial phase in the last two weeks of November 2010.

The main study project will entail three visits for each of 20 subjects (10 healthy control
subjects and 10 women with fibromyalgia. No treatments are planned for this project.

Procedures include: a) screening interview, diagnostic interview, analog rating scales, and
psychological and psychiatric rating scales; b) review of medical records if the diagnosis
of fibromyalgia is not certain; c) pain will be measured by palpation at tender points and
by measurement of biceps reflex that objectively measures amount of pain both before and
after visits, d) Visit A will include a special diet for breakfast at 8 AM and resting at
room temperature for 2.5 hours (both known to turn off brown fat) before receiving FDG
(radioactive sugar) and a PET/CT scan to measure metabolism e) Visit B requires another diet
and resting for 2.5 hours at ~62°F (both known to turn on brown fat) along with the PET/CT
scan to measure metabolism and a structural MRI to examine brain structure and to measure
volume of brown fat in chest; f) blood samples will be collected to measure stress hormones
before and after each warm or cold period; g) pregnancy testing before PET/CT and MRI.

Inclusion Criteria:

- Female

- 18-50 years of age and premenopausal fibromyalgia or 30-50 years of age and
premenopausal for healthy volunteers

- Healthy volunteer or diagnosis of fibromyalgia

- In follicular phase (Days 1-12) of menstrual cycle OR on contraceptives.

- Able to comply with study procedures.

- Capable of giving informed consent; consent obtained and form signed

Exclusion Criteria:

- Serious medical conditions (determined by investigator)

- Some medicines that affect brain metabolism (determined by investigator)

- Subjects who have participated in other studies with radioactivity may not be
eligible depending on prior exposure

- BMI more than 35 kg/m2 (i.e. severe obesity)

- Pregnant or nursing females

- Any condition that, in the investigator's opinion, makes the subject unsuitable for
study participation.