According to PAIN RESEARCH, Fibromyalgia syndrome (FMS) ranks among the most enigmatic and prevalent chronic pain conditions. Researchers and clinicians have searched in vain for an underlying cause for the unexplained widespread muscle pain, fatigue, and tenderness. In recent years, FMS has come to be seen as a “central” pain disorder, arising from changes in pain processing in the central nervous system. Now several new reports show evidence for peripheral nerve abnormalities in some FMS patients that could contribute to their chronic pain.
In a separate study that appeared June 5 in Pain, Anne Louise Oaklander and her team at Massachusetts General Hospital, Boston, US, reported similar findings in a group of 27 people rigorously diagnosed with FMS: Skin biopsies from the legs revealed that 41 percent of the FMS patients had loss of small fiber innervation to levels considered clinically diagnostic for small fiber peripheral neuropathy (SFPN), a condition that can cause widespread pain.
A third study presented at the November 2012 meeting of the International Association for the Study of Pain by Serra showed functional abnormalities in the small nerve fibers of FMS patients to match the anatomical differences seen by Oaklander and Sommer.