Imagine someone you know telling you that she has been suffering from pain in her back and abdomen for many years. Despite seeing a number of doctors, she still does not have a diagnosis and has no treatment except for over-the-counter pain pills, which are not very helpful. She also has periods of depression for which she has been given antidepressants, and some of her doctors have implied that her pain complaints are "all in her head."
Her pain limits her physical activity, and she has gotten out of shape and is overweight. Her abdominal pain is associated with an irritable bowel, and it is worse during her menses since she has dysmenorrhea. To make matters worse, she does not feel rested even after being in bed for 8 or 9 hours. She has wondered if she has chronic fatigue syndrome since she is always fatigued.
One doctor suggested that her fatigue may be related to having had mono when she was in college. However, he doubts it has anything to do with her chronic pain. She overheard him telling his office nurse that he thinks she is hysterical since she always complains of severe pain from the blood pressure cuff whenever the staff check her pressure.
This imaginary patient is a fairly typical presentation for someone with fibromyalgia. Some patients have fewer problems and some have more. The essential feature is chronic pain without a clear anatomical abnormality such as osteoarthritis on x-ray.
Fibromyalgia is a common chronic pain syndrome that affects around 5% of the U. S. population. It is more common in women than men with a ratio of 2:1. Many people think of it as a purely adult disorder, but it can begin in childhood.
The cause is unknown, but there is evidence to show that it is a centralized pain state. That means that there is either an excess of certain neurotransmitters in the brain that amplify the perception of pain in the brain or a deficiency of other neurotransmitters that reduce pain perception. As a result, relatively minor pressure or heat will be felt as much more severe than people without fibromyalgia would experience.
The neurotransmitters are the same ones that are involved with mood, memory and sleep among other things. Thus, it should not be a surprise that there are commonly problems in these areas as well as the chronic pain problem.
No one knows why there is a difference in neurotransmitters in these patients, but studies show that fibromyalgia has a significant genetic component. Besides the genetic role, there are known triggers for many patients. These include anything that may cause acute pain (e.g., trauma), some infections (e.g., EB virus, hepatitis, Lyme Disease), and stress.
The diagnosis is based on getting a compatible history with an absence of physical and lab studies showing a peripheral cause of the pain such as thyroid disease or arthritis. The physical exam is typically normal with the exception of tender trigger points in most patients.
The history commonly includes widespread pain and fatigue and may show cognitive problems, non-restful sleep, pain or cramps in the lower abdomen, depression, and/or headaches. There is no lab test or x-ray for fibromyalgia, but physicians will typically obtain some tests to rule out other causes for the symptoms.
Treatment includes educating the patient about their disease, encouraging them to play an active role in their own treatment, reducing stress, improving sleep, and exercise. The value of a graded exercise program is significant. Due to the pain it is usually necessary to start at very low levels and gradually work up to more vigorous exercise. Other treatments are of limited benefit if these measures are not taken.
Medications may provide some benefit if used in conjunction with the measures just described. They include a variety of types including tricyclics and pregabalin, to give a couple of examples. It is often beneficial to use more than one drug with different mechanisms of action. Some patients find trigger point injections to be helpful.
Complementary treatments may also be of help including acupuncture, yoga, and others. A minority of patients may benefit from use of a transcutaneous nerve stimulator.
In summary, fibromyalgia is a common rheumatologic disorder of unknown cause, which appears to be related to altered levels of certain neurotransmitters that are involved with the brain's perception of pain. It is not a psychological disorder but a biological one, although it is common to have associated psychiatric disorders such as depression or anxiety. These may be related to the altered levels of neurotransmitters and/ or the stress of coping with chronic pain. Although there is no cure, treatment such as those described above can enable most of these patients to lead productive, satisfying lives.
Peter M. Hartmann, MD
Psychiatry & Family Medicine
