Neurophysiologic assessment in the management of spinal dysraphism

Neurophysiologic techniques provide a valuable addition to the armamentarium of tools for the evaluation of sensory and motor function in the pediatric spinal cord. These techniques include median, radial, and ulnar nerve evoked potentials from the upper extremity; common peroneal and tibial nerve evoked potentials from the lower extremity; dermatomal potentials; and compound muscle action potentials and compound nerve action potentials. The techniques that evaluate the sensory system have been used extensively and effectively as research tools, as adjuncts to diagnostic evaluation, and for intraoperative monitoring. There is a considerable literature that describes the properties of SEPs in the infant and young child. Techniques for assessing the descending pathways have been developed in the last 10 years. These techniques hold great promise as both diagnostic and intraoperative monitoring tools. Many questions, however, still exist concerning their value and use. The rapidly increasing capability available in computer systems is also providing enhanced capability in the acquisition, display, and analysis of neurophysiologic data. It is now common to acquire multiple responses simultaneously, e.g. tibial SEPs, pudendal SEPs, and motor potentials. It is also possible to apply computationally intensive numerical algorithms in real time to enhance signal quality and reduce the time required to produce an interpretable display. Finally, it is possible to monitor multiple cases simultaneously from remote locations. These enhanced computational capabilities are helping to optimize the contribution of neurophysiologic monitoring to patient care.