1. An implantable medical device to treat a medical condition in a patient, the implantable medical device comprising: a cathode and an anode configured to be coupled to an electrical signal generator and to be coupled to a cranial nerve of the patient; a third electrode configured to be implanted within the patient and configured to be coupled to the electrical signal generator; wherein the electrical signal generator is configured to deliver a first electrical signal to the cathode and to the anode during a first time period, wherein the first electrical signal causes depolarization of a first portion of the cranial nerve proximate to the cathode and causes hyperpolarization of a second portion of the cranial nerve proximate to the anode, and wherein the electrical signal generator is configured to deliver a second electrical signal to the anode and to the third electrode during a second time period following the first time period, wherein the hyperpolarization of the second portion of the cranial nerve caused by the first electrical signal persists when the second electrical signal is delivered and delivery of the second electrical signal continues the hyperpolarization of the second portion of the cranial nerve.