Different intraoperative neuromonitoring modalities (mixed-nerve somatosensory-evoked potential [M-SSEP], dermatomal somatosensory-evoked potential [D-SSEP], compound motor-evoked potential [CMEP], electromyography [EMG], and the Hoffmann reflex [H-reflex]) have been developed for early detection of nerve root injury, for timely revision, and for damage reduction. In this study, we discuss the advantages and disadvantages of M-SSEP and D-SSEP by reviewing experimental evidence from animal models and clinical practice.