Carpal tunnel syndrome in vibration disease

Abstract

The presence of carpal tunnel syndrome (CTS) in 125 forestry workers with exposure to vibration was examined clinically by electromyography and by determining vibration detection thresholds. Numbness of the hands was present in 43%, history of diminished hand muscle force in 15%, and Raynaud's phenomenon in 27%. The muscle weakness correlated significantly with motor nerve conduction velocity in the median nerve in both hands. In 25 forestry workers CTS was diagnosed. The condition was bilateral in 48%; otherwise it was more common on the right side. Fifteen patients were referred for surgery but because of spontaneous recovery or refusal by the patients only five underwent surgery; of these four improved. The motor conduction velocity of the ulnar nerve was decreased among patients with CTS supporting the idea that entrapment neuropathies in the hands may be due to tissue swelling caused by vibration at work. Total exposure time to vibration correlated with the decrease in motor conduction velocity in the ulnar nerve.Prolonged exposure to hand-arm vibration may cause peripheral neuropathy'2 with symptoms such as numbness and pain in the hands, nocturnal paresthesia, and muscle weakness.34 The vibration induced symptoms in the peripheral nerves may arise from vascular insufficiency of the minute nerve terminals,56 by damage to the non-specific myelin sheath,' by intraneural oedema leading to secondary nerve degeneration,7 or by isolated nerve damage due to entrapment.8

The prevalence of sensorineural symptoms attributable to hand-transmitted vibration in Great Britain: a national postal survey

“…However, in 2,328 subjects aged 30±59 years from two general population samples in Japan the prevalence of numbness was 13% in men and 29% in women [Mirbod et al, 1994]; and among 635 working-aged men who attended a Japanese health care center for a routine health check and who were not exposed occupationally to HTV, the prevalence of numbness in the ®ngers varied from 7% in service workers to 21% in craftsmen, production process workers and laborers [Iwata et al, 1987]. In occupational surveys, the prevalence of numbness or tingling of the hand or arm in workers with exposure to HTV has been reported to lie in the range of 30±80%, [Stewart and Goda, 1970;Taylor and Pelmear, 1975;Alaranta and Seppalainen, 1977;Matsumoto et al, 1977;Bovenzi et al, 1980;Miyashita et al, 1983;Harkonen et al, 1984;Pyykko, 1986;Grif®n, 1990;Koskimies et al, 1990;Letz et al, 1992;Bovenzi et al, 1994] while that in unexposed workers has varied between 6 and 21%, depending on the case de®nition [Matsumoto et al, 1977;Iwata et al, 1987;Letz et al, 1992;Bovenzi et al, 1994;]. In a study of foresters from Japan, the crude odds ratio (OR) of numbness of the ®ngers was 5.6 in vibratory tool users as compared with other workers [Matsumoto et al, 1977]; in a cross sectional survey of shipyard workers, the OR for numbness and tingling was 2.9 in HTV-exposed occupations compared with other jobs [Letz et al, 1992]; in an Italian investigation, the OR for numbness or tingling in the ®ngers and hands among stone carvers and quarry drillers was 3.5 when compared with stone workers who only performed manual tasks [Bovenzi et al, 1994]; and in gas distribution workers with the highest third of lifetime cumulative exposure, the OR for tingling or numbness was 2.3 in comparison with the lowest third [Palmer et al 1998b].…”

The clinical grading of Raynaud's phenomenon and vibration-induced white finger: relationship between finger blanching and difficulties in using the upper limb

“…Exposure to HTV is associated with several wellrecognised disorders of the upper limb, including Raynaud's phenomenon [18,31], digital polyneuropathy [1,31], carpal tunnel syndrome [15,28], arm and hand pain [30,19], and diculties with dexterity and strength of grip [26,32,30,6,7]. But an association between nonoccupational Raynaud's phenomenon and impaired function of the upper limb has seldom been reported, and then generally in the context of connective-tissue diseases such as scleroderma, in which function of the upper limb is likely be compromised by overt sclerotic injury and tethering [29].…”

Prevalence and pattern of occupational exposure to hand transmitted vibration in Great Britain: findings from a national survey

“…2Sensorineural impairment in the fingers2 3 and carpal tunnel syndrome4 5 are other reported hazards from use of vibratory tools, and osteoarthritis of the wrist and elbow have also been associated with HTV in some studies 6-9. The term hand-arm vibration syndrome (HAVS) has been used to define collectively the disorders thought to be associated with exposure to HTV 10…”