Tunnel syndromes of the upper extremities in workers using hand-operated vibrating tools.

Neurological and electrophysiological (EMG, ENG) examinations of the upper extremities were carried out in 167 patients exposed to hand-arm vibrations. All patients had typical symptoms (Raynaud's phenomenon and/or numbness, muscle weakness). The results showed that the circumscribed lesions of the tunnel nerves are far more common (92.8%) than diffuse peripheral neuropathies (22.7%). The most common alteration (71.4% below the border-line values) was the lesion of the brachial plexus in the thoracic outlet. In 16.2% of the patients compression of the subclavian artery was also demonstrated by means of a Doppler flowmeter. Cubital tunnel syndrome was observed in 42.5% of the patients. The results suggest that hand-arm vibration can play a part in the development of the thoracic outlet and cubital tunnel syndromes. On the other hand the thoracic outlet syndrome can contribute to the development of vibration-induced Raynaud's phenomenon.