Median Nerve Small- and Large-Fiber Damage in Carpal Tunnel Syndrome: A Quantitative Sensory Testing Study

Abnormalities of intraterritorial and extraterritorial sensory processing in carpal tunnel syndrome and their pathophysiological significance: A comment on the paper by Schmid et al. (Eur J Pain, 2011)

“…We agree with the authors' view that, because of their frequent comorbidity, coexisting upper-limb pain conditions need to be thoroughly excluded in studies exploring CTS pathophysiology (Zanette et al, 2006(Zanette et al, , 2010. There are, however, some discrepancies between the data from Schmid et al (2011) and previous reports (Zanette et al, 2010;Tamburin et al, 2011), and we will discuss some reasons for these contrasting findings.…”

“…Neuropathy of the median nerve and the palmar cutaneous branch may sometimes coexist, but the latter is usually uninvolved in CTS (Tagliafico et al, 2008). Testing a median territory, which is unaffected by CTS, may explain normal heat and vibration detection thresholds that are in contrast with previous reports (Tucker et al, 2007;Tamburin et al, 2011).…”

Reply to the letter to the editor by Tamburin and Zanette

“…We agree that our findings of normal warm detection thresholds in the median nerve territory of the hand are in contrast with the findings by Tamburin et al (2010). As mentioned in the Discussion of our article though, the literature on thermal detection thresholds in patients with CTS is conflicting with several other reports failing to identify altered thermal detection thresholds in this area (Borg and Lindblom, 1988;de la Llave-Rincon et al, 2009).…”

The relationship between QDASH scale and clinical, electrophysiological findings in carpal tunnel syndrome

“…Another reason for the lack of correlation between sensory symptom severity and electrodiagnostic findings is the central sensitization and plasticity that is triggered by abnormal median nerve imputes. 21 In clinical studies, laser-evoked potentials, sympathetic skin responses and quantitative sensory tests show that thin fibers were affected in CTS. However, no relationship was detected with electrophysiological data.…”

“…However, no relationship was detected with electrophysiological data. 21 Skin biopsy is the gold standard for demonstrating the affection of thin fibers. Recently, Schmind et al found a reduction in the density of intra-epidermal fibers in CTS histopathologically, and it has been reported that there was no correlation between this result and electrophysiological findings.…”