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Electrical Stimulation of the Human Descending Motor Tracts at Several Levels

Published online by Cambridge University Press:  18 September 2015

Yoshikazu Ugawa ,
Kieko Genba-Shimizu  and
Ichiro Kanazawa
Yoshikazu Ugawa*
Affiliation:
Department of Neurology, Institute for Brain Research, School of Medicine, University of Tokyo, Tokyo
Kieko Genba-Shimizu
Affiliation:
Department of Neurology, Institute for Brain Research, School of Medicine, University of Tokyo, Tokyo
Ichiro Kanazawa
Affiliation:
Department of Neurology, Institute for Brain Research, School of Medicine, University of Tokyo, Tokyo
*
Department of Neurology, Institute for Brain Research, School of Medicine, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan
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Abstract:

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The descending motor tracts were activated using a high voltage electrical stimulation technique at four levels: the motor cortex, brainstem (around the pyramidal decussation), and the first and sixth thoracic vertebral levels (Tl, T6). Electromyographic activity was recorded from the tibialis anterior or extensor digitorum brevis muscles. Consistent motor action potentials could be evoked in all normal subjects. The conduction velocity of the descending tracts was estimated to be 62 to 79 m/s. The sum of synaptic delay and utilization time at the motoneurons (spinal delay time) was estimated to be 0.5 ± 0.3 ms indicating a mono- or oligosynaptic connection. In patients with diffusely affected descending tracts, the technique showed slowed conduction along the descending tracts and prolonged spinal delay time which may include the time required for temporal summation of excitatory postsynaptic potentials as well as synaptic delay and utilization time. In patients with a localized lesion, localized conduction delay was found at the appropriate segment.

Type
Original Articles
Information
Canadian Journal of Neurological Sciences , Volume 22 , Issue 1 , February 1995 , pp. 36 - 42
Copyright
Copyright © Canadian Neurological Sciences Federation 1995

References

1. Murray, NMF.The clinical usefulness of magnetic cortical stimulation. Electroencephalogr Clin Neurophysiol 1992; 85: 81–85.CrossRefGoogle ScholarPubMed
2. Ugawa, Y, Rothwell, JC, Day, BL, Thompson, PD, Marsden, CD.Magnetic stimulation over the spinal enlargements. J Neurol Neurosurg Psychiatry 1989; 52: 1025–1032.CrossRefGoogle ScholarPubMed
3. Ugawa, Y, Rothwell, JC, Day, BL, Thompson, PD, Marsden, CD.Percutaneous electrical stimulation of corticospinal pathways at the level of the pyramidal decussation in humans. Ann Neurol 1991; 29:418–427.CrossRefGoogle ScholarPubMed
4. Ugawa, Y, Genba, K, Mannen, T, Kanazawa, I.Stimulation of corticospinal pathways at the level of the pyramidal decussation in neurological disorders. Brain 1992; 115: 1947–1961.CrossRefGoogle ScholarPubMed
5. Snooks, SJ, Swash, M.Motor conduction velocity in the human spinal cord: slowed conduction in multiple sclerosis and radiation myelopathy. J Neurol Neurosurg Psychiatry 1985; 48: 1135–1139.CrossRefGoogle ScholarPubMed
6. Ugawa, Y, Genba, K, Shimpo, T, Mannen, T.Physiologic analysis of central motor pathways – simultaneous recording from multiple relaxed muscles. Eur Neurol 1989; 29: 135–140.CrossRefGoogle ScholarPubMed
7. Maertens de Noordhout, A, Rothwell, JC, Thompson, PD, Day, BL, Marseen, CD.Percutaneous electrical stimulation of lumbosacral roots in man. J Neurol Neurosurg Psychiatry 1988; 51: 174–181.CrossRefGoogle ScholarPubMed
8. Kimura, J.F-wave velocity in the central segment of the median and ulnar nerves: a study in normal subjects and patients with Charcot-Marie-Tooth disease. Neurology 1974; 24: 539–546.CrossRefGoogle ScholarPubMed
9. Donaldson, HH, Davis, DJ.A description of charts showing the areas of the cross section of the human spinal cord at the level of each spinal nerve. J Comp Neurol 1903; 13: 19–40.CrossRefGoogle Scholar
10. Shimada, Y.Brain and spinal cord in Japanese. In: Jinruigakusenshikoza, Tokyo: Youhikaku, 1939; vol 3, 1–188 (in Japanese).Google Scholar
11. DeJong, RN.The Neurologic Examination. Hagerstown, Harper & Row, 1979.Google Scholar