Involvement of thin afferents in carpal tunnel syndrome: Evaluated quantitatively by argon laser stimulation
Article first published online: 13 OCT 2004
Copyright © 1991 John Wiley & Sons, Inc.
Muscle & Nerve
Volume 14, Issue 6, pages 508–514, June 1991
How to Cite
Arendt-Nielsen, L., Gregersen, H., Toft, E. and Bjerring, P. (1991), Involvement of thin afferents in carpal tunnel syndrome: Evaluated quantitatively by argon laser stimulation. Muscle Nerve, 14: 508–514. doi: 10.1002/mus.880140604
- Issue published online: 13 OCT 2004
- Article first published online: 13 OCT 2004
- Manuscript Accepted: 21 MAR 1990
- carpal tunnel syndrome;
- pain-evoked potentials;
- argon laser stimulation;
- pain threshold
The thin afferent nerves were tested quantitatively by determining the thresholds of warmth and pricking pain to argon laser stimulation and by measuring the brain potentials related to pricking pain. In 27 patients with electrophysiologically verified carpal tunnel syndrome these parameters were measured from fingers 3 and 5 on both hands. All patients had had sensory symptoms ranging from 3 months to 25 years. Both the thresholds were elevated (P <0.05) at finger 3 compared to measurements from finger 5, and compared to finger 3 in a group of 39 controls. Four patients with symptoms for more than 7 years had thresholds below the control values. The power of the pain-evoked brain potentials elicited from finger 3 was lower (P <0.05) compared to finger 5, and compared to the control group (P <0.01). No correlations were found between the measured parameters and the clinical electrophysiological investigation. The findings support previous assumptions that chronic low-force compressions cause impairment of intraneural microcirculation, and hence can affect the function of the thin afferents.