Fig. 1

Study design. The study design consists of a 1-month pre-treatment evaluation phase, a phase of thalamic stimulation alone (1 month), then thalamic and anterior cingulate (ACC) stimulation (3 months), followed by a cross-over randomized phase comparing ACC stimulation “On” (3 months) and “Off” (3 months) periods, and then an open phase (12 months)