Randomized Single Blind Sham Controlled Trial of Adjunctive Home-Based tDCS after rTMS for Mal De Debarquement Syndrome: Safety, Efficacy, and Participant Satisfaction Assessment

Background Mal de debarquement syndrome is a medically refractory disorder characterized by chronic rocking dizziness that occurs after exposure to passive motion. Repetitive transcranial magnetic stimulation (rTMS) can acutely suppress the rocking dizziness but treatment options that extend the benefit of rTMS are needed. Objectives 1) To determine whether transcranial direct current stimulation (tDCS) added after rTMS can extend the benefit of rTMS; 2) to determine whether participants can safely perform tDCS at home. Methods Participants were given five days of rTMS (1 Hz right DLPFC/10 Hz left DLPFC in right-handers, vice versa in left-handers), according to a previously piloted protocol. They received three days of training on tDCS self-administration and were then randomized to either real or sham tDCS for four-weeks (anode left DLPFC/cathode right DLPFC for right-handers, vice versa for left-handers). Results Twenty-three participants completed the study. Those who received real tDCS after rTMS showed significant improvements in the degree of rocking perception as measured by the MdDS Balance Rating Scale and anxiety ratings by Week 4 of tDCS and a trend for improvement on the Dizziness Handicap Inventory. Two rTMS non-responders responded well to subsequent open-label tDCS. Side effects were mild and not different between real and sham tDCS. There were no episodes of skin burns in a group total of 556 sessions of tDCS. Satisfaction was rated high. Conclusions Home-based tDCS can be performed safely and may be beneficial in selected individuals. Adequate teaching, automatic device safety features, and a good communications infrastructure are components of successful home therapy.