Are there biological markers of neuropathic pain?: Commentary on a paper by Saika et?al. (, this issue).

摘要

This is another attempt at identifying biological markers for pain in humans from skin biopsies, which ends with a negative result, but yields some interesting information outside the original research question. Preferably, such a biomarker should result from a noninvasive or minimally invasive test, and Martin Schmelz and colleagues (Schley et al., 2012) employ a comprehensive battery of such tests, including bedside examination, quantitative sensory testing, axon reflex flare and the quantification of skin innervation. In contrast to most previous authors who tried to correlate skin innervation with pain, they took great care in separating skin nerve fibres into different layers and correlated their quantity with sensory function like thermal thresholds or the degree of electrically induced pain.