Skip to main content
NCBI home page
Journal of Neurology, Neurosurgery, and Psychiatry logoLink to Journal of Neurology, Neurosurgery, and Psychiatry
. 1989 Feb;52(2):213–217. doi: 10.1136/jnnp.52.2.213

High-voltage stimulation over the human spinal cord: sources of latency variation.

B L Plassman 1, S C Gandevia 1
PMCID: PMC1032508  PMID: 2539436

Abstract

Percutaneous electrical stimuli (up to 600 V) were applied over the cervical spinal cord to evoke responses in the biceps brachii and thenar muscles. Cathodal stimulation over the C7 spinous process was more effective than anodal stimulation or stimulation over the C5 or C3 spinous process. As the stimulus intensity was increased, the response amplitude increased and the latency decreased. When progressively higher levels of supramaximal stimuli were delivered the latency often decreased further. The shortest latencies evoked by stimulation over the C7 spinous process were close to the latencies of the responses evoked by supramaximal stimulation near Erb's point. Thus, with this type of stimulation, the site of nerve activation changes with different stimulus intensities. The variability in latency introduced by distal spread of the site of activation will affect measurements of central motor conduction time and should be considered in the diagnostic use of this technique.

Full text

PDF
213

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Berardelli A., Inghilleri M., Formisano R., Accornero N., Manfredi M. Stimulation of motor tracts in motor neuron disease. J Neurol Neurosurg Psychiatry. 1987 Jun;50(6):732–737. doi: 10.1136/jnnp.50.6.732. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Cowan J. M., Rothwell J. C., Dick J. P., Thompson P. D., Day B. L., Marsden C. D. Abnormalities in central motor pathway conduction in multiple sclerosis. Lancet. 1984 Aug 11;2(8398):304–307. doi: 10.1016/s0140-6736(84)92683-7. [DOI] [PubMed] [Google Scholar]
  3. Gandevia S. C., Plassman B. L. Responses in human intercostal and truncal muscles to motor cortical and spinal stimulation. Respir Physiol. 1988 Sep;73(3):325–337. doi: 10.1016/0034-5687(88)90054-0. [DOI] [PubMed] [Google Scholar]
  4. Gandevia S. C., Rothwell J. C. Activation of the human diaphragm from the motor cortex. J Physiol. 1987 Mar;384:109–118. doi: 10.1113/jphysiol.1987.sp016445. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Ingram D. A., Swash M. Central motor conduction is abnormal in motor neuron disease. J Neurol Neurosurg Psychiatry. 1987 Feb;50(2):159–166. doi: 10.1136/jnnp.50.2.159. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Maertens de Noordhout A., Rothwell J. C., Thompson P. D., Day B. L., Marsden C. D. Percutaneous electrical stimulation of lumbosacral roots in man. J Neurol Neurosurg Psychiatry. 1988 Feb;51(2):174–181. doi: 10.1136/jnnp.51.2.174. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Merton P. A., Morton H. B. Stimulation of the cerebral cortex in the intact human subject. Nature. 1980 May 22;285(5762):227–227. doi: 10.1038/285227a0. [DOI] [PubMed] [Google Scholar]
  8. Mills K. R., Murray N. M. Corticospinal tract conduction time in multiple sclerosis. Ann Neurol. 1985 Nov;18(5):601–605. doi: 10.1002/ana.410180514. [DOI] [PubMed] [Google Scholar]
  9. Mills K. R., Murray N. M. Electrical stimulation over the human vertebral column: which neural elements are excited? Electroencephalogr Clin Neurophysiol. 1986 Jun;63(6):582–589. doi: 10.1016/0013-4694(86)90145-8. [DOI] [PubMed] [Google Scholar]
  10. Robinson L. R., Jantra P., MacLean I. C. Central motor conduction times using transcranial stimulation and F wave latencies. Muscle Nerve. 1988 Feb;11(2):174–180. doi: 10.1002/mus.880110214. [DOI] [PubMed] [Google Scholar]
  11. Rossini P. M., Caramia M., Zarola F. Central motor tract propagation in man: studies with non-invasive, unifocal, scalp stimulation. Brain Res. 1987 Jul 14;415(2):211–225. doi: 10.1016/0006-8993(87)90203-4. [DOI] [PubMed] [Google Scholar]
  12. Rossini P. M., Marciani M. G., Caramia M., Roma V., Zarola F. Nervous propagation along 'central' motor pathways in intact man: characteristics of motor responses to 'bifocal' and 'unifocal' spine and scalp non-invasive stimulation. Electroencephalogr Clin Neurophysiol. 1985 Oct;61(4):272–286. doi: 10.1016/0013-4694(85)91094-6. [DOI] [PubMed] [Google Scholar]
  13. Rothwell J. C., Thompson P. D., Day B. L., Dick J. P., Kachi T., Cowan J. M., Marsden C. D. Motor cortex stimulation in intact man. 1. General characteristics of EMG responses in different muscles. Brain. 1987 Oct;110(Pt 5):1173–1190. doi: 10.1093/brain/110.5.1173. [DOI] [PubMed] [Google Scholar]
  14. Snooks S. J., Swash M. Motor conduction velocity in the human spinal cord: slowed conduction in multiple sclerosis and radiation myelopathy. J Neurol Neurosurg Psychiatry. 1985 Nov;48(11):1135–1139. doi: 10.1136/jnnp.48.11.1135. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Thompson P. D., Day B. L., Rothwell J. C., Dick J. P., Cowan J. M., Asselman P., Griffin G. B., Sheehy M. P., Marsden C. D. The interpretation of electromyographic responses to electrical stimulation of the motor cortex in diseases of the upper motor neurone. J Neurol Sci. 1987 Aug;80(1):91–110. doi: 10.1016/0022-510x(87)90224-3. [DOI] [PubMed] [Google Scholar]
  16. Thompson P. D., Dick J. P., Asselman P., Griffin G. B., Day B. L., Rothwell J. C., Sheehy M. P., Marsden C. D. Examination of motor function in lesions of the spinal cord by stimulation of the motor cortex. Ann Neurol. 1987 Apr;21(4):389–396. doi: 10.1002/ana.410210412. [DOI] [PubMed] [Google Scholar]
  17. Wiederholt W. C. Threshold and conduction velocity in isolated mixed mammalian nerves. Neurology. 1970 Apr;20(4):347–352. doi: 10.1212/wnl.20.4.347. [DOI] [PubMed] [Google Scholar]
  18. Young R. R., Cracco R. Q. Clinical neurophysiology of conduction in central motor pathways. Ann Neurol. 1985 Nov;18(5):606–610. doi: 10.1002/ana.410180515. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Neurology, Neurosurgery, and Psychiatry are provided here courtesy of BMJ Publishing Group

RESOURCES