Premium
Differential involvement of myelinated and unmyelinated nerve fibers in painful diabetic polyneuropathy
Author(s) -
Galosi Eleonora,
Di Pietro Giuseppe,
La Cesa Silvia,
Di Stefano Giulia,
Leone Caterina,
Fasolino Alessandra,
Di Lionardo Andrea,
Leonetti Frida,
Buzzetti Raffaella,
Mollica Cristina,
Cruccu Giorgio,
Truini Andrea
Publication year - 2021
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.27080
Subject(s) - polyneuropathy , neuropathic pain , medicine , nerve fiber , allodynia , diabetic neuropathy , nerve conduction velocity , anesthesia , nociception , diabetes mellitus , hyperalgesia , anatomy , endocrinology , receptor
Abstract Background We aimed at evaluating the differential involvement of large myelinated Aβ‐, small myelinated Aδ‐, and unmyelinated C‐fibers in patients with diabetic polyneuropathy and how they contribute to neuropathic pain. Methods We collected clinical and diagnostic test variables in 133 consecutive patients with diabetic polyneuropathy. All patients underwent Aβ‐fiber mediated nerve conduction study, Aδ‐fiber mediated laser‐evoked potentials and skin biopsy mainly assessing unmyelinated C‐fibers. Results Pure large‐fiber and small‐fiber polyneuropathy were relatively uncommon; conversely mixed‐fiber polyneuropathy was the most common type of diabetic polyneuropathy (74%). The frequency of neuropathic pain was similar in the three different polyneuropathies. Ongoing burning pain and dynamic mechanical allodynia were similarly associated with specific small‐fiber related variables. Conclusions Diabetic polyneuropathy mainly manifests as a mixed‐fiber polyneuropathy, simultaneously involving Aβ‐, Aδ‐, and C‐fibers. In most patients, neuropathic pain is distinctly associated with small‐fiber damage. The evidence that the frequency of neuropathic pain does not differ across pure large‐, pure small‐, and mixed‐fiber polyneuropathy, raises the possibility that in patients with pure large‐fiber polyneuropathy nociceptive nerve terminal involvement might be undetected by standard diagnostic techniques.