Effects of occupational use of vibrating tools in the autonomic, central and peripheral nervous system

• Published in: International archives of occupational and environmental health 1997, Vol.70 (2), p.94-100
• Main Authors: MURATA, K, ARAKI, S, OKAJIMA, F, NAKAO, M, SUWA, K, MATSUNAGA, C
• Format: Article
• Language: English
• Subjects: Adult; Autonomic Nervous System - physiopathology; Biological and medical sciences; Case-Control Studies; Central Nervous System - physiopathology; Electrocardiography; Evoked Potentials, Somatosensory; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Male; Matched-Pair Analysis; Medical sciences; Middle Aged; Neural Conduction; Occupational Diseases - etiology; Occupational Diseases - physiopathology; Occupational Exposure - adverse effects; Peripheral Nervous System - physiopathology; Statistics, Nonparametric; Traumas. Diseases due to physical agents; Vibration - adverse effects
• ISSN: 0340-0131; 1432-1246
• DOI: 10.1007/s004200050192

The objective of this study was to clarify the autonomic, central and peripheral nervous effects of vibrating-tool operation. The ECG R-R interval variability (CVRR), including the C-CVHF, C-CVLF (two component CVs of the CVRR reflecting parasympathetic and sympathetic activities, respectively) and the power spectral densities (PSDHF and PSDLF) after autoregressive analysis, short-latency somatosensory evoked potentials (SSEP), distribution of nerve conduction velocities (DCV), and median and radial nerve conduction velocities (NCVs) were measured in 17 vibrating-tool operators and the same number of age-matched control subjects. Some of the operators complained of white finger even in summer as soon as they arrived at the cold workplace. The significance of the differences in neurophysiological data between the exposed and unexposed groups and the associations between these data in the former were investigated. The CVRR, C-CVHF and PSDHF were significantly lower in the vibrating-tool operators than in the matched controls. The N9-N13 interpeak latency of the SSEP, i.e., conduction time of the cervico-spinobulbar pathway, in the operators was significantly prolonged as compared with the controls; the faster velocities of the DCV and the NCVs were significantly slowed in the operators. The N9-N13 interpeak latency in the operators was significantly correlated with the C-CVHF. Complex stressors of local vibration, cold, noise and heavy work, seem to affect the cervico-spinobulbar, parasympathetic and peripheral nerve functions. Also, parasympathetic hypofunction may imply a consequence in brainstem pathology induced by cold exposure in addition to vibration.