Deep brain stimulation (DBS) has helped more than 100 000 patients with conditions such as Parkinson disease, essential tremor, dystonia, and obsessive-compulsive disorder, and it holds great potential for other conditions, such as depression and other neuropsychiatric disorders. The delivery of DBS requires an invasive implant, and this presents the potential for surgical complications.1 Changing the stimulation target is also limited given the local nature of the implant. Noninvasive brain stimulation methods, such as transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES), have been used in many clinical and neuroscientific investigations and do not require surgery.2 Noninvasive methods easily permit changes in the stimulation target. However, for TMS or TES to directly stimulate deep brain structures requires stronger stimulation of overlying (eg, cortical) areas, which may result in unanticipated adverse effects and encroach on safety guidelines.3 Ideally, technology would offer the focality of DBS but the noninvasiveness of TMS or TES. Developing such a device would require invention, experiments, and clinical trials. These could be facilitated by collaboration between inventors and clinicians and partnerships with funders (eg, the National Institutes of Health)….
