http://www.sciencedirect.com/science/article/pii/S0093934X15302005 Unfortunately TCDS was not successful in treating stuttering. This was just a first pass, there may be other things to study in the future. edit: I should clarify, TCDS is not deep brain stimulation. Deep brain stimulation is entirely too invasive to be a suitable treatment for stuttering. I highly doubt any attempt will be made to study deep brain stimulation for stuttering.