Vibration-induced neuropathy among forestry workers.

The neurological findings of 217 forestry workers were evaluated during a compulsory annual health examination. Vibration detection thresholds were determined for the left hand and foot. The handgrip forces were measured for both hands. A reduction in the vibration detection threshold or handgrip force was not associated with clinical neuropathy. Polyneuropathy was found in 4% of the lumberjacks whereas neuropathy restricted to the arms was found in 7.5% of the lumberjacks. The neuropathic findings were not linked with alcohol consumption but were associated with a history of numbness in the hands and diminished muscle force. The findings support the concept that local vibration can cause neuropathy in the arms, but the mechanism of vibration-induced neuropathy still remains uncertain.