Nerve conduction in relation to vibration exposure - a non-positive cohort study

Area of Science:

• Occupational Health
• Neurology
• Epidemiology

Background:

• Peripheral neuropathy is a key disorder in hand-arm vibration syndrome (HAVS).
• Previous electrophysiological studies on HAVS have yielded inconsistent results.
• A lack of longitudinal studies with robust exposure assessment and disease measurement contributes to this inconsistency.

Purpose of the Study:

• To investigate the relationship between long-term hand-arm vibration exposure and peripheral nerve conduction in manual workers.
• To assess nerve conduction velocities and latencies in relation to cumulative vibration dose.

Main Methods:

• A cohort of 155 male office and manual workers was studied.
• Hand-arm vibration dose was calculated over 21 years (1987-2008).
• Nerve conduction studies (distal motor latencies, sensory conduction) were performed in 2008 after systemic warming.

Main Results:

• No significant differences in sensory or motor nerve conduction latencies were found between exposed and unexposed workers.
• The prevalence of pathological nerve conduction and carpal tunnel syndrome symptoms was similar in both groups.

Conclusions:

• Nerve conduction measurements did not reveal an exposure-response association between hand-arm vibration and distal neuropathy of large myelinated fibers.
• Findings suggest that hand-arm vibration exposure, as measured, may not be a primary cause of distal neuropathy in this cohort.