Pathophysiology and clinical picture of hand-arm vibration syndrome in Japanese workers.

Hand-arm vibration syndrome is an occupational disease induced by long-term use of vibratory tools such as rock drills and chain saws. The three major stressors of vibration, noise and cold may produce various symptoms and signs not only with peripheral circulatory, nervous and muscle-joint disorders but also with general disorders. It is a point of controversy whether the symptoms and signs should be limited in the peripheral disorders. The question may involve differences in definition: vibration alone or work mode with vibratory tools. There are two viewpoints in the staging: peripheral and general viewpoints. The key concept in the peripheral viewpoint staging is a checkup to find disorders at the early stage and classify the peripheral disorders of the digits in detail. The general viewpoint staging seeks to grasp the general pictures of patients, and to classify from light to severe cases in the treatment. Clinical manifestations may include the general disorders in proportion to the severity of the syndrome according to our clinical experience. A differential diagnosis should be carefully made in the light of legal, medical and economic compensation. The treatments that we have used for approximately 20 years have beneficial effects on the whole-body, which include 1) physiobalneotherapy (therapeutic exercise, exercise in a pool and physiotherapy), 2) drug therapy (vasodilating drugs, autonomic stabilizers, etc.), 3) nerve blocking therapy, 4) surgical therapy for ulnar nerve paralysis or paresis, and 5) education for patients. Even with these therapies, a beneficial effect may not be observed in a short period. The recovery may be slow.(ABSTRACT TRUNCATED AT 250 WORDS)