1. A neurostimulation system, comprising: stimulation output circuitry configured for delivering stimulation pulses to target tissue in accordance with a set of stimulation parameters; monitoring circuitry configured for continuously measuring action potentials evoked in the target tissue in response to the delivery of the stimulation pulses to the target tissue; memory configured for storing a characteristic of a reference evoked action potential; and at least one processor configured for initiating an automatic mode, in which a characteristic of the measured evoked action potentials is compared to the corresponding characteristic of the reference evoked action potential, and one or more stimulation parameter values in the set of stimulation parameters are adjusted to decrease or increase the energy level of the stimulation pulses, thereby evoking action potentials in the target tissue having substantially the same corresponding characteristic as the reference evoked action potential.