Bioelectric brain activity in workers with hand-arm vibration in dynamics

Abstract

Introduction. A few neurophysiologic studies have shown that changes of the bioelectrical brain activity are observed in hand-arm vibration syndrome (HAVS) patients. There is practically no information about the state of bioelectrical brain activity in the hand-arm vibration. The purpose is to study the dynamics of the formation of neurophysiologic changes in workers exposed to hand-arm vibration. Materials and methods. Electroencephalography (EEG) and registration of evoked potentials (EP) was carried out in workers exposed to hand-arm vibration (practically healthy workers, HAVS individuals who continue to work in their occupation), twice in a connected sample. The results are presented as median, upper and lower quartiles, and extensive indicators. The significance of differences was assessed using Pearson’s χ2 test, Fisher’s angular transformation, and Wilcoxon T-test. Results. In dynamics, there is a change in the EEG pattern from disorganized with a predominance of alpha activity to disorganized with a predominance of delta, and theta activity; a decrease in the spectral power of the main EEG rhythms in all main functional leads in both examined groups. Diffuse changes in the EEG indicate a multisystem nature of bioelectrical brain activity disorders with involvement of the cerebral cortex, stem, and diencephalic structures of the brain. Changes in the amplitude-temporal parameters of EP manifested by an excess of the latency of the main peaks and a decrease in amplitude, indicate an imbalance in the central nervous system, general modulating influences on the cerebral cortex of the thalamocortical systems of the brain. Limitations. One occupational group with different levels of health status – practically healthy workers, HAVS individuals who continue to work in their occupation – was enrolled in the study. Conclusion. The one-direction and progressive development of changes in the bioelectrical brain activity has been established, manifested by a restructuring of the electrical activity of the brain, desynchronization of neuronal activity, an increase in the level of functional activity of the brain, and an imbalance of general modulating influences on the cerebral cortex. The identified changes are a manifestation of the nonspecific part of the pathogenesis of HAVS.