1. An implantable medical device (IMD) to treat a medical condition in a patient, comprising: an electrical signal generator; a cathode and an anode operatively coupled to the electrical signal generator and a cranial nerve of the patient; a third electrode operatively coupled to the electrical signal generator and implanted within the patient's body; wherein: the electrical signal generator is capable of generating and delivering at least one electrical signal effective at the anode to block at least a sufficient portion of action potentials induced by the at least one electrical signal in the cranial nerve proximate the cathode to reduce a side effect of said induced action potentials.