Fibromyalgia and other chronic pain syndromes

Hmm since fibromyalgia is in the news nowdays, maybe it is a good time to talk about it on the braindiseases weblog. I did my internal medicine residency before I did neurology and I remember reading about fibromyalgia in Harrison’s Principles and Practices of Internal Medicine (this book is called the bible of internal medicine, a book every good internal medicine doctor should know well). Fibromyalgia occupied half a page and was right at the end of the section a kind of neglected disease. Many doctors (and I include myself in that group) do not consider that the disease actually exists.

We all have patients in our practice who carry the diagnosis of fibromyalgia, they have constant complain of pain in different areas of the body. When they first present to a doctor a work-up is carried out to determine the etiology of this constant pain. However inspite of multiple tests including but not limited to blood tests, imaging studies and sometimes even invasive studies no cause can be found. All the inflammatory markers in the blood come back negative (these include tests like ESR). These patients frequently have other diagnosis which fall into the category of psychosomatic disorders like IBS (irritable bowel syndrome) and chronic fatigue syndrome. Some of them may carry psychiatric diagnosis like depression or somatisation disorder. Thus fibromyalgia has been in the past a kind of waste-basket diagnosis given to patients with unexplained complaint of chronic pain referrable to different parts of the body. Since we did not truly believe that the disease exists, we did not have any good treatments for it. Doctors either treated these patients with anti-depressants or pain killers. This caused some unintended problems with some patients becoming dependent on pain killers like vicodin.

So do we know anything more of fibromyalgia now than in the 90’s?

Do we understand its pathophysiology better today?

Does the disease actually exists?

Fibromyalgia is currently diagnosed as per the criteria laid out by the American College of Rheumatology (ACR).

FIBROMYALGIA CRITERIA

A. Widespread pain must be present for at least 3 months. This pain must appear in all of the following locations:

  • Both sides of the body
  • Above and below the waist
  • Along the length of the spine

B. Pain in at least 11 of 18 specific areas called tender points on the body. The pain experienced when pressing on a tender point is very localized and intensely painful (not just tender). Tender points are located in the following areas:

  • The left or right side of the back of the neck, directly below the hairline
  • The left or right side of the front of the neck, above the collar bone (clavicle)
  • The left or right side of the chest, right below the collar bone
  • The left or right side of the upper back, near where the neck and shoulder join
  • The left or right side of the spine in the upper back between the shoulder blades (scapula)
  • The inside of either arm, where it bends at the elbow
  • The left or right side of the lower back, right below the waist
  • Either side of the buttocks below the hip bones
  • Either knee cap

Other long-term symptoms that may indicate fibromyalgia include:

  • Morning stiffness
  • Fatigue
  • Sleep disturbance
  • Numbness or tingling in the hands and feet
  • Headache

We nowdays think that these patients have an altered perception of pain and other visceral as well as somatic sensations. Let me explain this with a crude example. Suppose you have inflammation in your left shoulder joint, your brain shall get sensation from the sensory receptors located in the periphery of the joint.  The sensation shall travel to the sensory cortex of the brain (the part of the brain dealing with sensation) and you shall experience pain as a result. It is believed that fibromyalgia patients have altered pain perception in their brain, they either feel the pain too much or that it persists for longer than it is supposed to (crudely put maybe their brain is more pain sensitive). Some recent work involving functional MRI and other imaging studies does give some scientific evidence to suggest this.

Whatever the etiopathogenesis behind this disorder (if in fact the disorder does exist in the first place) now there are new drugs in the market been touted (and FDA approved) for the treatment of fibromyalgias. One of them is pregabalin marketed under the name of Lyrica. My personal experience using this drug in patients with fibromyalgia is very limited. If you or any of your loved ones is diagnosed with fibromyalgia, I would advise you to see a doctor with interest and experience in this disorder so that you can get benefits of newer treatment modalities.

Personal Regards,

Nitin Sethi, MD