Fibromyalgia may be caused by nerve damage

More patients with fibromyalgia suffer from migraine headaches than those without this fibromyalgia. Those with fibromyalgia are also more likely to have irritable bowel syndrome, depression, and panic attacks. Fibromyalgia has been a mysterious and an ill-defined condition. However, after years of research specific criteria for the diagnosis were developed and several drugs for fibromyalgia were approved by the FDA (Lyrica, Cymbalta, Savella).

A new study by researchers at the Massachusetts General Hospital suggests that half of the patients with symptoms of fibromyalgia have damaged peripheral nerves, a condition called small-fiber neuropathy. They compared skin biopsies (a test to diagnose the neuropathy) in 25 patients with fibromyalgia and 29 healthy controls. In healthy controls only 17% had neuropathy. This type of neuropathy can also occur in diabetics, but none of the 25 patients in the study had diabetes. Other conditions that can cause small-fiber neuropathy are cancer, autoimmune conditions, various toxins, vitamin B12 deficiency, and genetic disorders, but none of these were present either, except for possibly genetic cause since three patients were related (a mother and two daughters).

The practical importance of this finding is that sometimes neuropathy responds to immune therapies, such as intravenous gamma globulin.