Tardy effect of neurogenic muscular atrophy by magnetic stimulation.

The influence of pulsed magnetic stimulation on denervated muscles was investigated in this study. Of 24 rats divided into three groups for experiment, 8 rats served as control; 16 rats with bilaterally severed sciatic nerves were divided into two groups for different modes of stimulation. Magnetic stimulation with a high power output that induced an intensive contraction of muscle was applied at one side-denervated gastrocnemius muscle for 1 mo in a group of rats; electric stimulation with high intensity at 6 Hz frequency and 1-ms pulse duration served as a contrast in the other group. Muscular weight, volume, fiber diameter and percentage of fiber types were measured after the experiment. A significant retardation of weight loss in denervated muscles via magnetic stimulation (P < 0.05) was confirmed by observed results. Type II fiber atrophy was retarded in denervated muscles by magnetic stimulation as well as in denervated muscles via electric stimulation. Magnetic stimulation, used as a method that induces muscular activity, was verified in this study as being capable of retarding denervated muscular atrophy. Its benefits of painless stimulation as well as deeply activated muscular contraction could be expected to function as a new model for rehabilitation of paralyzed muscles.