A method is provided for optimization of a stimulation specificity and an energy consumption of implanted electrodes in excitable tissue of a patient. The method may involve electrically stimulating excitable tissue between one or more combinations of electrode pairs in a cluster of electrodes, or electrically stimulating excitable tissue between one or more combinations of electrode pairs in two or more clusters of electrodes. The two electrodes of the electrode pairs may not belong to a same cluster. Each of the electrodes may be located on a physically separated entity, such that the tissue surrounds and separates each electrode from all other electrodes, thereby allowing tissue between the electrodes to be stimulated. An electrode pair or pairs which give rise to a lowest energy consumption while still giving a therapeutic effect may be chosen. Alternatively, each electrode pair may be assigned a value related to the information provided by the patient and the energy consumption, and the electrode pair or pairs which give(s) rise to a most favorable assigned value may be chosen.