Chronic pain has a small influence and mood has no influence on vibrotactile perception thresholds among working women

Helena Sandén,Mats Hagberg,B Gunnar Wallin

doi:10.1002/mus.21697

Abstract

In chronic diffuse upper limb pain physical abnormalities are usually absent. The aims of our study were to investigate: (1) the function of somatosensory pathways and (2) the influence of mood on vibration perception. Measurements were made of: (i) vibrotactile perception thresholds (VPTs) and nerve conduction in working women with (n = 35) and without (n = 65) chronic diffuse upper limb pain, and (ii) perceived stress and energy using a two-dimensional mood adjective checklist. The groups did not differ in any nerve conduction measurements. Women with chronic pain had raised VPTs in the radial and ulnar nerve areas, but not in the median nerve area. Neither perceived stress nor energy appeared to influence the VPT. Increases of VPTs in chronic diffuse upper limb pain may be due to peripheral nerve affliction, but our findings support the idea that they may also be secondary to pain and may be related to a central nervous mechanism. Muscle Nerve, 2010

Highlights

Chronic diffuse upper limb pain is common, its etiology is sometimes uncertain
The control group passed the medical examination without signs of nervous system disease and had no history of pain with long duration in recent years, and only a few members of this group reported acute temporary pain in connection with medical examination and/or vibration threshold testing
The main findings in this study were: (1) perceived stress and energy did not influence the vibrotactile perception threshold Key words (VPT); (2) there was a small influence of chronic diffuse upper limb pain on VPTs, with increased thresholds seen in the area of the ulnar and radial nerve in female workers with normal nerve conduction; and (3) there was no difference in conduction velocity between the groups

Summary

Introduction

Chronic diffuse upper limb pain is common, its etiology is sometimes uncertain. Chronic diffuse upper limb pain may be due to minor nerve entrapments, but a standard physical examination is unlikely to demonstrate abnormality. The aim of this study was to investigate the function of the somatosensory pathways using vibration threshold testing and nerve conduction measurements in the upper extremity in working women with and without chronic diffuse upper limb pain. The invitation referred to working women with and without chronic upper limb pain. The final study population included 35 individuals with chronic diffuse upper limb pain, age 30–65 (median 46) years and 65 individuals without chronic pain, age 24–57 (median 42) years. The medications being taken by the participants with chronic pain included nonnarcotic analgesics (2), antidepressants (1), antihistamines (1), bronchodilators (1), thyroid hormones (1), diuretics (1), and hypolipidemic agents (2). Two participants were on long-term treatment with antidepressants due to recurring depression; at the time of the examination there were no clinical signs of ongoing depression

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