Spinal Cord Monitoring — A Review of Current Techniques and Knowledge
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.
KeywordsEpidural Space Spinal Cord Stimulation Posterior Tibial Nerve Stimulation Primary Afferent Depolarization Spinal Cord Function
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Andersen P et al. (1962) Presynaptic inhibitory action of cerebral cortex on the spinal cord. Nature 194:740–741PubMedCrossRefGoogle Scholar
Engberg et al. (1968) Reticulospinal inhibition of interneurones. J Physiol 194:225–236PubMedGoogle Scholar
Ertekin C (1978) Evoked electrospinogram in spinal cord and peripheral nerve disorders. Acta Neurol Scand 57:329–344PubMedCrossRefGoogle Scholar
Kaieda R et al. (1981) Effects of diazepam on evoked electrospinogram and evoked electromyogram in man. Anesth Analg 60:197–200PubMedGoogle Scholar
Kano T, Shimoji K (1974) The effects of ketamine and neuroleptanalgesia on the evoked electrospinogram and electromyogram in man. Anesthesiology 40:241–246PubMedCrossRefGoogle Scholar
Kurokawa T (1980) Functional spinal cord monitoring in spinal surgery through evoked spinal cord action potential measurement (in Japanese). Clinical Electroenceph 22:464–470Google Scholar
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 88:499–519PubMedGoogle Scholar
Martin RF et al. (1979) Primary afferent depolarization of identified cutaneous fibers following stimulation in medial brain stem. J Neurophysiol 42:779–790PubMedGoogle Scholar
Maruyama Y et al. (1980) Effects of morphine on human spinal cord and peripheral nervous activities. Pain 8:63–73PubMedCrossRefGoogle Scholar
Maruyama Y et al. (1982) Human spinal cord potentials evoked by different sources of stimulation and conduction velocities along the cord. J Neurophysiol 48:1098–1107PubMedGoogle Scholar
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 191Google Scholar
Moore DC (1965) Regional block. Thomas, Springfield, 111, p 427Google Scholar
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 113–124Google Scholar
Shimizu H et al. (1979a) Interaction between human evoked electrospinograms elicited by segmental and descending volleys. Experientia 35:1199–1200PubMedCrossRefGoogle Scholar
Shimizu H et al. (1979b) Slow cord dorsum potentials elicited by descending volleys in man. J Neurol Neurosurg Psychiatry 42:242–246PubMedCrossRefGoogle Scholar
Shimizu H et al. (1982) Human spinal cord potentials produced in lumbosacral enlargement by descending volleys. J Neurophysiol 48:1108–1120PubMedGoogle Scholar
Shimoji K et al. (1971) Epidural recording of spinal electrogram in man. Electroencephalogr Clin Neurophysiol 30:236–239PubMedCrossRefGoogle Scholar
Shimoji K et al. (1972) Evoked spinal electrograms recorded from epidural space in man. J Appl Physiol 33:468–471PubMedGoogle Scholar
Shimoji K et al. (1974) The effects of thiamylal sodium on electrical activities of the central and peripheral nervous systems in man. Anesthesiology 40:234–240PubMedCrossRefGoogle Scholar
Shimoji K et al. (1975) Presynaptic inhibition in man during anesthesia and sleep. Anesthesiology 43:388–391PubMedCrossRefGoogle Scholar
Shimoji K et al. (1976) Interactions of human cord dorsum potential. J Appl Physiol 40:79–84PubMedGoogle Scholar
Shimoji K et al. (1977) Wave-form characteristics and spatial distribution of evoked spinal electrogram in man. J Neurosurg 46:304–313PubMedCrossRefGoogle Scholar
Tamaki T et al. (1981) The prevention of iatrogenic spinal cord injury utilizing the evoked spinal cord potentials. Internat Orthop 4:313–317Google Scholar
Tang AH (1969) Dorsal root potentials in the chloralose-anesthetized cat. Exp Neurol 25:393–400PubMedCrossRefGoogle Scholar
© Springer-Verlag Berlin Heidelberg 1985