A neurophysiological monitoring system includes at least one surgical instrument having at least one magnetometer and a control unit configured to receive magnetic field data generated by the at least one magnetometer. The control unit may provide stimulation to a nerve at a known stimulation time and receive magnetic field data from the at least one magnetometer indicative of a response to stimulation of the nerve at a receive time. An interpretation of the magnetic field data based upon the receive time and the stimulation time may be generated.