1. A method comprising: with one or more processors, selecting a predefined set of electrode combinations, wherein each electrode combination of the predefined set includes one or more anode electrodes and one or more cathode electrodes, a relative arrangement of the one or more anodes and the one or more cathodes defining an electrode pattern of the electrode combination; and with the one or more processors, automatically controlling a medical device to deliver, in a predetermined order, electrical stimulation to a patient via each electrode combination of the predefined set of electrode combinations, wherein the electrode combinations in the predetermined order define a repeating sequence of electrode patterns.