Investigating how coil designs and anatomical variations affect the efficacy of cerebellar TMS

Transcranial magnetic stimulation (TMS) is a neuromodulation technique a non-invasive treatment for various neurological disorders such as major depressive disorder. Cerebellum is a complex structure connected with almost the entire central nervous system, and TMS has promise for non-invasively probing cerebellar function. Therefore, TMS has been gaining popularity in the field of neurostimulation of cerebellum. Recent studies have reported that cerebellum plays an important role not only in motor planning and behavior but also in the cognitive domain. Nevertheless, few studies have explored how different coil designs and anatomical variations affect the effectiveness of cerebellar TMS. In this work, we investigated the effects of cerebellar TMS with different coil designs positioning on several locations. Finite element modeling was conducted with Figure-of-8 coil and DB-80 coil. Each coil was positioned in the center, 1 cm and 3 cm to the left with respect to the center of the cerebellum and all the locations were tangential to the scalp at a distance of 5 mm. Furthermore, the commercial head model MIDA and 50 MRI derived head models were used in the computer modelling to examine how anatomical variations affect the efficacy of cerebellar TMS.