Differential coding of cold allodynia – a fmri study

Aim of Investigation: The pathophysiology of cold allodynia, a typical sign of neuropathic pain, is unclear. Two complementary mechanisms have been postulated: sensitization of peripheral nociceptive structures and disinhibition of central processing of C-fiber nociceptive input. Aim of this study was to explore the „peripheral sensitization“ and „central disinhibition“ mechanism of cold allodynia in humans. Methods: In eight healthy male volunteers, topical menthol (peripheral sensitization of C-fibers) or conduction block of A-fiber input (central disinhibition due to mechanical conduction block of myelinated…