Interestingly, they report on 2 patients who continued to have excellent tic improvement despite battery depletion, while another patient experienced severe rebound effect. Another case report of a patient with Centromedian/Parafascicular (Cm/Pf)  stimulation who experienced severe tic status following battery depletion was published this year (Parmera). The mechanisms of these ongoing responses or rebound effects remain to be investigated.