Modeling Studies of Cervical Thoracic Sympathetic Nerve Magnetic Stimulation

Abstract

Abstract Background Electromagnetic fields have been administered, with mixed success, in order to treat a variety of ailments. During the update of magnetic stimulation technology, modelling studies play an important role. To numerically investigate the possibility of cervical thoracic sympathetic nerve magnetic stimulation with current commercial figure-eight coil commonly used in the implementation of Transcranial magnetic stimulation, and improve coil design specially for cervical thoracic sympathetic nerve magnetic stimulation, we conducted this modelling study. Results We simulated the induced currents and induced electric fields at the cervicothoracic sympathetic and spinal nerves under different simulation study settings; compared and displayed the induced electric field distribution and induced currents at the level of the cervicothoracic sympathetic ganglia (stellate ganglia) At the same time, we recorded the specific values of the maximum induced current density of the cervical and thoracic sympathetic nerves and spinal nerves and compared them. Conclusions For current commercial figure-eight coils, in order to obtain the best magnetic stimulation results, we should place the figure-eight coils 19 mm away from the midline of the front of the human neck and rotate the coil to a certain angle to fit the human neck as closely as possible. And properly enlarging the size of the traditional figure-eight coil can obtain a stronger stimulation effect on cervical thoracic sympathetic nerve. However, the anatomical depth of the cervical thoracic sympathetic nerve is relatively deep while the induced electric field generated by the current commercial figure-eight coil decays rapidly with the stimulation depth, stimulation effect of figure-eight coil is not good enough. Although the traditional double-cone coil can theoretically achieve a deeper stimulation depth, the good fit of the double-cone coil to the neck becomes another practical problem to be solved. Our results provide guidance for further clinical volunteer trials and the development of cervical magnetic stimulation devices. We believe that this conclusion may become a weather vane for the study of cervical thoracic sympathetic nerve.