Dorsal root entry zone localization using direct spinal cord stimulation: an experimental study

Direct spinal cord stimulation and recording was performed in five dogs to identify the dorsal root entry zone (DREZ) and long tracts within the dorsal and dorsolateral spinal cord using electrophysiological mapping techniques. Intrathecal recordings were obtained from sites distal to the site of stimulation. Conduction velocity in the fastest conducting fibers was higher following low-intensity stimulation of the dorsolateral spinal cord than after dorsal spinal cord stimulation. The evoked response was larger following dorsolateral than dorsal spinal cord stimulation at a specific stimulus intensity. This technique is useful in identifying the DREZ using electrophysiological criteria alone.