Threshold for Transcranial Magnetic Stimulation of the foot: precise control of coil orientation with a robotized system

Introduction: For transcranial magnetic stimulation (TMS) precise positioning of the stimulation coil is required. In clinical routine ‘standard’ coil orientations are used. Studies investigating the optimal coil orientation have been very coarse. The most detailed studies addressed the hand region, with rotation steps as large as 45°. For the stimulation of the right leg a left-to-right coil orientation is the standard orientation. We show that this orientation is not optimal. Materials: We used a MC-B70 Butterfly coil and a MagPro X100 stimulator with MagOption (MagVenture A/S, Farum, Denmark) for stimulation.…