Posture Effect of Spinal Column on Central Conduction Time of the Spinal Cord

J Korean Assoc EMG Electrodiagn Med 1999;1(1):72-75.
Published online January 1, 1999.

Abstract

Objectives : To evaluate the effect of a postural change of spine on the central conduction times (CCTs) in the sensory and motor pathway of the spinal cord using somatosensory evoked potentials (SEPs) and motor evoked potentials(MEPs). Methods : Fourteen men and one woman without neurologic deficit were included in this study. SEPs and MEPs were used to evaluate the CCTs of the spinal cord according the regions in the spinal cord. SEPs were recorded at Cz'-Fz (International 10-20 system)and the first lumber spinous process by stimulation of the tibial nerve at the ankle in hyperextension and hyperflexion of the spinal column. MEPs were obtained at the tibialis anterior muscle by a magnetic stimulus for the recording of cortical and spinal MEPs (C3 and first lumber spinous process) in hyperextension and hyperflexion of the spinal column. The CCTs of the spinal cord were defined as the latency difference between P1 latency of the cortical SEPs and N1 latency of the spinal SEPs and onset latencies of cortical and spinal MEPs. Results : There was a significant difference in the CCYs of SEPs and MEPs between hyperextension and hyperflexion of the spinal column (p<0.05, respectively). However, the difference of variation rate of the SSTs according to the two postures between SEPs and MEPs was not significant(p>0.05). Conclusion : This study showed that hyperflexion from hyperextension of the spinal column prolongs the CCTs of SEPs and MEPs, However, the posture change does not play in differenr central conduction delay of the spinal cord between the pathways of SEPs and MEPs.

Key Words: Central conduction time, Spinal cord, Hyperextension, Hypergflexion, Spinal column