Premium
Involvement of thin afferents in carpal tunnel syndrome: Evaluated quantitatively by argon laser stimulation
Author(s) -
ArendtNielsen Lars,
Gregersen Hans,
Toft Egon,
Bjerring Peter
Publication year - 1991
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.880140604
Subject(s) - carpal tunnel syndrome , stimulation , medicine , electrophysiology , median nerve , index finger , anesthesia , sensory system , surgery , anatomy , psychology , neuroscience
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.