1. A system, comprising: a neural stimulator configured to generate neural stimulation signals for use in delivering neural stimulation; a controller connected to the neural stimulator, the controller and the neural stimulator being configured to generate a first neural stimulation signal for use in delivering unidirectional afferent neural stimulation to a target nerve for a neural stimulation therapy, and to generate a second neural stimulation signal for use in delivering efferent neural stimulation to the target nerve, wherein in delivering the efferent neural stimulation, a measurable physiologic effect is elicited by nerve traffic an efferent direction, and wherein in delivering the unidirectional afferent neural stimulation, the measurable physiologic effect is not elicited; at least one sensor configured to sense a physiologic response for the measurable physiologic effect to the efferent neural stimulation of the target nerve; and the controller being connected to the at least one sensor, the controller being configured to compare a sensed physiologic response to the efferent neural stimulation to a desired response, and adjust at least one efferent neural stimulation parameter for the second neural stimulation signal for use in delivering efferent neural stimulation that results in the desired physiologic response, the controller further being configured to deliver the unidirectional afferent neural stimulation using afferent neural stimulation parameters determined using the at least one efferent neural stimulation parameter that provided the desired physiological response.