Breakthrough research: small-fiber polyneuropathy underlies illness in some patients diagnosed as fibromyalgia
Small-fiber neuropathy is a neurological illness characterized by degeneration of C and A-delta fibers
(i.e. the axons that are responsible for nociceptive transmission).
Patients with small-fiber neuropathy often have widespread pain, a characteristic of fibromyalgia.
Besides pain, small-fiber neuropathy symptoms include gastrointestinal and autonomic symptoms
(e.g. sweating and cardiovascular problems).
Fibromyalgia is characterized by hypersensitivity of the central nervous system (central sensitization),
without objective damage to the peripheral or central nervous system.
Hence, fibromyalgia pain is classified as central sensitization pain rather than neuropathic pain.
Two research teams, one from Boston (USA) and the second from Würzburg (Germany), have discovered
that a subgroup of fibromyalgia has small-fiber neuropathy.
This was shown using skin biopsies and autonomic tests.
Similar findings were done in children with chronic widespread pain.
Although the number of patients studied was rather small, these findings are compelling and require more research.
In fact, it would imply that a significant number of patients currently labeled as fibromyalgia,
have neuropathic (i.e. small-fiber neuropathy) rather than central sensitization pain.
The debate whether small-fiber neuropathy should be excluded for establishing the diagnosis of fibromyalgia can begin…