Small-fiber involvement in diabetic patients with neuropathic foot pain
| Authors | |
|---|---|
| Year of publication | 2008 |
| Type | Article in Periodical |
| Magazine / Source | Diabetic Medicine |
| MU Faculty or unit | |
| Citation | |
| Field | Neurology, neurosurgery, neurosciences |
| Keywords | Diabetic neuropathy; pain; small-fiber; thermal threshold; skin biopsy |
| Description | Aims: To assess small-fiber involvement in diabetic patients with neuropathic pain. Methods: Peripheral nerve function was evaluated in a cohort of 30 patients with diabetes mellitus type 2 (DM2, 24 patients) or impaired glucose tolerance (IGT, 6 cases), and clinical symptoms of neuropathic pain in the feet, using nerve conduction studies, autonomic tests, thermal quantitative sensory testing (T-QST) and the quantification of intra- and subepidermal nerve fiber densities in skin punch biopsies. Results: Clinical signs of isolated small-fiber sensory involvement were present in 13 patients (pure small-fiber neuropathy - pSFN), 7 patients had isolated positive sensory symptoms without neurological deficits (pSFN-). Ten patients had concomitant electrophysiological and/or clinical signs of large-fiber sensory involvement (mixed-fiber neuropathy - MFN). Twenty seven patients (90%) had both reduced skin innervation and abnormalities of the T-QST parameters. Two other patients displayed either abnormal skin innervation or T-QST and only one patient had normal findings on both tests. The criteria of small-fiber neuropathy (SFN) were met in all 20 patients without large-fiber involvement. Small fiber involvement was also present in the10 MFN patients. Both T-QST and skin biopsy parameters revealed significant differences between these clinical subgroups, with increased severity of small-fiber involvement in the MFN group. Autonomic dysfunction was found in 43% of patients and did not correlate with either clinical, T-QST or skin biopsy data. Conclusions: Although the exact mechanism of neuropathic pain in diabetic patients is not known, pain is almost invariably accompanied by small-fiber dysfunction and pathology irrespective of autonomic or large-fiber involvement. |
| Related projects: |