Summary
The epidural recording of human SCP could provide extensive information on spinal cord function during anesthesia and surgery when several technical procedures are properly handled.
Three kinds of human SCPs can be recorded from the epidural space: the segmental and conductive SCPs, and the SCP produced by the descending volley. The segmental SCP consists of an initially positive spike (P1) followed by sharp negative (N1) and slow positive (P2) potentials, which are very similar in waveform to those in animals. The conductive or ascending SCP is composed usually of three spike-like potentials, sometimes followed by a negative slow wave. The SCP produced in the lumbosacral enlargement by the descending volley manifests itself as initial spikes followed by sharp negative-positive waves which are alike in waveform to the segmentally evoked SCP.
Anesthetics differentially affect each component of the segmental SCP. Hypoxia and acidosis suppress the SCP studied in the rat. The suppression is most pronounced in the P2 wave and “the heterosegmental potential.” The N1 amplitude is also decreased by hypoxia, with prolongation of its duration.
The simultaneous recording of other electrical activities along the sensory pathways, such as the SEP from the scalp, may provide a more accurate evaluation of spinal cord function during surgery.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Andersen P et al. (1962) Presynaptic inhibitory action of cerebral cortex on the spinal cord. Nature 194:740–741
Engberg et al. (1968) Reticulospinal inhibition of interneurones. J Physiol 194:225–236
Ertekin C (1978) Evoked electrospinogram in spinal cord and peripheral nerve disorders. Acta Neurol Scand 57:329–344
Kaieda R et al. (1981) Effects of diazepam on evoked electrospinogram and evoked electromyogram in man. Anesth Analg 60:197–200
Kano T, Shimoji K (1974) The effects of ketamine and neuroleptanalgesia on the evoked electrospinogram and electromyogram in man. Anesthesiology 40:241–246
Kurokawa T (1980) Functional spinal cord monitoring in spinal surgery through evoked spinal cord action potential measurement (in Japanese). Clinical Electroenceph 22:464–470
Magladery JW et al. (1951) Electrophysiological studies of nerve reflex activity in normal man. IV. The two-neurone reflex and identification of certain action potentials from spinal roots and cord. Bull Johns Hopkins Hosp 88:499–519
Martin RF et al. (1979) Primary afferent depolarization of identified cutaneous fibers following stimulation in medial brain stem. J Neurophysiol 42:779–790
Maruyama Y et al. (1980) Effects of morphine on human spinal cord and peripheral nervous activities. Pain 8:63–73
Maruyama Y et al. (1982) Human spinal cord potentials evoked by different sources of stimulation and conduction velocities along the cord. J Neurophysiol 48:1098–1107
Maruyama Y et al. (1984) Spinal cord function monitoring by spinal cord potentials during spine and spinal surgery. In: Homma S, Tamaki T (eds) Fundamentals and clinical application of spinal cord monitoring. Saikon, Tokyo, p 191
Moore DC (1965) Regional block. Thomas, Springfield, 111, p 427
Schramm J et al. (1984) Relevance of spinal cord evoked injury potential for spinal cord monitoring. In: Homma S, Tamaki T (eds) Fundamentals and clinical application of spinal cord monitoring. Saikon Publishing, Tokyo, pp 113–124
Shimizu H et al. (1979a) Interaction between human evoked electrospinograms elicited by segmental and descending volleys. Experientia 35:1199–1200
Shimizu H et al. (1979b) Slow cord dorsum potentials elicited by descending volleys in man. J Neurol Neurosurg Psychiatry 42:242–246
Shimizu H et al. (1982) Human spinal cord potentials produced in lumbosacral enlargement by descending volleys. J Neurophysiol 48:1108–1120
Shimoji K et al. (1971) Epidural recording of spinal electrogram in man. Electroencephalogr Clin Neurophysiol 30:236–239
Shimoji K et al. (1972) Evoked spinal electrograms recorded from epidural space in man. J Appl Physiol 33:468–471
Shimoji K et al. (1974) The effects of thiamylal sodium on electrical activities of the central and peripheral nervous systems in man. Anesthesiology 40:234–240
Shimoji K et al. (1975) Presynaptic inhibition in man during anesthesia and sleep. Anesthesiology 43:388–391
Shimoji K et al. (1976) Interactions of human cord dorsum potential. J Appl Physiol 40:79–84
Shimoji K et al. (1977) Wave-form characteristics and spatial distribution of evoked spinal electrogram in man. J Neurosurg 46:304–313
Tamaki T et al. (1981) The prevention of iatrogenic spinal cord injury utilizing the evoked spinal cord potentials. Internat Orthop 4:313–317
Tang AH (1969) Dorsal root potentials in the chloralose-anesthetized cat. Exp Neurol 25:393–400
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1985 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Shimoji, K., Maruyama, Y., Shimizu, H., Fujioka, H., Taga, K. (1985). Spinal Cord Monitoring — A Review of Current Techniques and Knowledge. In: Schramm, J., Jones, S.J. (eds) Spinal Cord Monitoring. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-70687-5_2
Download citation
DOI: https://doi.org/10.1007/978-3-642-70687-5_2
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-70689-9
Online ISBN: 978-3-642-70687-5
eBook Packages: Springer Book Archive