Skip to main content
NCBI home page
Journal of Neurology, Neurosurgery, and Psychiatry logoLink to Journal of Neurology, Neurosurgery, and Psychiatry
. 1990 Oct;53(10):874–879. doi: 10.1136/jnnp.53.10.874

Neurophysiological observations on corticospinal projections to the upper limb in subjects with Rett syndrome.

J A Eyre 1, A M Kerr 1, S Miller 1, M C O'Sullivan 1, V Ramesh 1
PMCID: PMC488249  PMID: 2266369

Abstract

The aim of the present study was to investigate the excitability of corticospinal neurons and the integrity of their projections to the alpha motor neurons through the corticospinal tract in subjects of different ages with Rett syndrome. Electromagnetic stimulation of the motor cortex and cervical motor roots was used to evoke motor action potentials in the biceps brachii and hypothenar muscles. The phasic stretch reflex in the biceps brachii was also recorded to study the excitability of spinal alpha motor neurons. Motor cortex stimulation evoked motor action potentials at low threshold and with abnormally short latencies and prolonged durations. In contrast cervical motor root stimulation resulted in responses of normal latency and duration. The phasic stretch reflex had a low threshold, short latency and prolonged duration. It is concluded that in Rett syndrome the corticospinal pathway is intact. The results suggest disordered synaptic control of the Betz cell of the motor cortex and/or the spinal alpha motor neuron, although the involvement of the latter might be a consequence of dysfunction in supraspinal descending motor pathways.

Full text

PDF
874

Selected References

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

  1. Badr G. G., Witt-Engerström I., Hagberg B. Brain stem and spinal cord impairment in Rett syndrome: somatosensory and auditory evoked responses investigations. Brain Dev. 1987;9(5):517–522. doi: 10.1016/s0387-7604(87)80076-1. [DOI] [PubMed] [Google Scholar]
  2. Barker A. T., Freeston I. L., Jalinous R., Jarratt J. A. Magnetic stimulation of the human brain and peripheral nervous system: an introduction and the results of an initial clinical evaluation. Neurosurgery. 1987 Jan;20(1):100–109. doi: 10.1097/00006123-198701000-00024. [DOI] [PubMed] [Google Scholar]
  3. Day B. L., Dressler D., Maertens de Noordhout A., Marsden C. D., Nakashima K., Rothwell J. C., Thompson P. D. Electric and magnetic stimulation of human motor cortex: surface EMG and single motor unit responses. J Physiol. 1989 May;412:449–473. doi: 10.1113/jphysiol.1989.sp017626. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Edgley S. A., Eyre J. A., Lemon R. N., Miller S. Excitation of the corticospinal tract by electromagnetic and electrical stimulation of the scalp in the macaque monkey. J Physiol. 1990 Jun;425:301–320. doi: 10.1113/jphysiol.1990.sp018104. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hagberg B., Aicardi J., Dias K., Ramos O. A progressive syndrome of autism, dementia, ataxia, and loss of purposeful hand use in girls: Rett's syndrome: report of 35 cases. Ann Neurol. 1983 Oct;14(4):471–479. doi: 10.1002/ana.410140412. [DOI] [PubMed] [Google Scholar]
  6. Ho H. H., Wong P. K., Robertson R. Rett syndrome: clinical profile and EEG abnormalities. Clin Invest Med. 1988 Jun;11(3):234–241. [PubMed] [Google Scholar]
  7. Jellinger K., Seitelberger F. Neuropathology of Rett syndrome. Am J Med Genet Suppl. 1986;1:259–288. doi: 10.1002/ajmg.1320250528. [DOI] [PubMed] [Google Scholar]
  8. Kerr A. M., Montague J., Stephenson J. B. The hands, and the mind, pre- and post-regression, in Rett syndrome. Brain Dev. 1987;9(5):487–490. doi: 10.1016/s0387-7604(87)80070-0. [DOI] [PubMed] [Google Scholar]
  9. Kerr A. M., Stephenson J. B. A study of the natural history of Rett syndrome in 23 girls. Am J Med Genet Suppl. 1986;1:77–83. doi: 10.1002/ajmg.1320250509. [DOI] [PubMed] [Google Scholar]
  10. Kerr A. M., Stephenson J. B. Rett's syndrome in the west of Scotland. Br Med J (Clin Res Ed) 1985 Aug 31;291(6495):579–582. doi: 10.1136/bmj.291.6495.579. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Koh T. H., Eyre J. A. Maturation of corticospinal tracts assessed by electromagnetic stimulation of the motor cortex. Arch Dis Child. 1988 Nov;63(11):1347–1352. doi: 10.1136/adc.63.11.1347. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Mills K. R., Murray N. M., Hess C. W. Magnetic and electrical transcranial brain stimulation: physiological mechanisms and clinical applications. Neurosurgery. 1987 Jan;20(1):164–168. doi: 10.1097/00006123-198701000-00033. [DOI] [PubMed] [Google Scholar]
  13. Plassman B. L., Gandevia S. C. High-voltage stimulation over the human spinal cord: sources of latency variation. J Neurol Neurosurg Psychiatry. 1989 Feb;52(2):213–217. doi: 10.1136/jnnp.52.2.213. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Rett A. Uber ein eigenartiges hirnatrophisches Syndrom bei Hyperammonämie im Kindersalter. Wien Med Wochenschr. 1966 Sep 10;116(37):723–726. [PubMed] [Google Scholar]
  15. Rothwell J. C., Day B. L., Thompson P. D., Dick J. P., Marsden C. D. Some experiences of techniques for stimulation of the human cerebral motor cortex through the scalp. Neurosurgery. 1987 Jan;20(1):156–163. doi: 10.1097/00006123-198701000-00032. [DOI] [PubMed] [Google Scholar]
  16. Southall D. P., Kerr A. M., Tirosh E., Amos P., Lang M. H., Stephenson J. B. Hyperventilation in the awake state: potentially treatable component of Rett syndrome. Arch Dis Child. 1988 Sep;63(9):1039–1048. doi: 10.1136/adc.63.9.1039. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Verma N. P., Chheda R. L., Nigro M. A., Hart Z. H. Electroencephalographic findings in Rett syndrome. Electroencephalogr Clin Neurophysiol. 1986 Nov;64(5):394–401. doi: 10.1016/0013-4694(86)90072-6. [DOI] [PubMed] [Google Scholar]
  18. Verma N. P., Nigro M. A., Hart Z. H. Rett syndrome--a gray matter disease? Electrophysiologic evidence. Electroencephalogr Clin Neurophysiol. 1987 Oct;67(4):327–329. doi: 10.1016/0013-4694(87)90118-0. [DOI] [PubMed] [Google Scholar]

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

RESOURCES