[Quantitative analysis of spinal cord injury using the isopotential spinal cord surface mapping].

To evaluate spinal cord injury quantitatively and qualitatively, distribution of spinal cord surface potentials were analyzed using a isopotential mapping technique. The segmental spinal evoked potential was recorded simultaneously with 21-42 silver ball electrodes applied to the dorsal and ventral surface of the lumbar spinal cord of 37 anesthetized cats. The severity of spinal cord lesion was divided into 5 grades from 100 gcf to 500 gcf according to Allen's weight drop method. An analysis of isopotential map was made up to 24 hours after trauma. The results showed that N3 which was considered as the interneuron activity projecting from the dorsal horn to the anterior horn, revealed no shift of localization. It was therefore appeared appropriate for use as a parameter for quantitative analysis, especially in subtract and variation maps. The data provided not only amplitude and latency but also two dimensional surface spreads of electricity.