Dermatomal Somatosensory Evoked Potential (DSEP) の頸髄神経根レベルでの検討

抄録

A dermatome is an area of skin innervated by nerve fibers which pass through one spinal dorsal root. The aim of this experiment is to investigate the sensitivity and selectivity of dermatomal somatosensory evoked potential (DSEP) and peripheral antidromic sensory response (ASR) by selective rhizotomy (dorsalor ventral), using anesthetized monkey. The spinal cord at C4-T1 was exposed under anesthesia. In DSEP, we stimulated the dermatomes of deltoid, thumb, index finger and little finger, and recorded from cervical spine and scalp. ASR was recorded from peripheral dermatomes by stimulating C1-C2. The dorsal rhizotomy selectively demonstrated the decrease of amplitude or loss to the root lesion, and high sensitivity in both of DESP and ASR. Ventral rhizotomy showed no selectivity. The selectivity of DSEP and ASR suggested the usefulness for diagnosis of radiculopathies. Furthermore, ASR was evaluated to be a reliable method to spinal cord monitoring because of the simplicity or the accuracy.