[Disorders of neuromuscular transmission in patients with vibration-induced disease]

The author presents the data of electrophysiologic investigation of distal axon and synaptic structures in patients of different occupations (reveters, choppers, polishers) exposed to medium or high frequency vibration. A correlation analysis of SEMG index relation with the duration of service in confact with vibration showed it to cause two types of defects in neuromuscular transmission: myastenic and "increment" syndrome. The former correlated with vibratoin exposure, the letter--with duration of service. It was suggested to regard two types of synaptic disorders as a denervation reinnervation stage in axons terminals. Compensatory potential of axons is rather small, reinnervation capacities are short-termed and in spite of the absence of degenerative changes of axons advace. Mechanisms of traumatic effect of vibration on synaptic structures responsible for subsequent neuro-reflectory and neuro-trophyc changes of motor neuron of the spinal cord, were assertained according to SEMG, EMG and correlation analysis.