Annals of Biomedical Engineering

, Volume 20, Issue 2, pp 225–236 | Cite as

Attenuation of pathological tremors by functional electrical stimulation II: Clinical evaluation

  • Manouchehr Javidan
  • Josef Elek
  • Arthur Prochazka
Article

Abstract

In this study we evaluated a technique for tremor suppression with functional electrical stimulation (FES), the technical details of which were described in the previous paper. Three groups of patients were investigated: those with essential tremor, parkinsonian tremor, and cerebellar tremor associated with multiple sclerosis. In each group, tremor was attenuated by significant amounts (essential tremor: 73%; parkinsonian tremor: 62%; cerebellar tremor: 38%). These attenuations were in good accord with predictions based on the dynamic analyses and filter designs derived in the previous paper. With filters “tuned” to the lower mean tremor frequency encountered in the cerebellar patients, more attenuation was possible in this group as well. We identified some practical limitations in the clinical application of the technique in its present form. The most important was that in daily use, only one antagonist pair of muscles can realistically be controlled. At first sight, this restricts the usefulness of the system to patients with single-joint tremors. However, the concomitant use of mechanical orthoses may broaden the scope of application.

Keywords

Tremor suppression Cerebellum 

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References

  1. 1.
    Freund, H.-J.; Hefter, H.; Homberg, V.; Reiners, K. Determinants of tremor rate. In: Findley, L.J.; Capildeo, R., eds. Movement disorders: Tremor. London: Macmillan; 1984: pp. 195–204.Google Scholar
  2. 2.
    Hewer, L.R.; Cooper, R.; Morgan, M.H. An investigation into the value of treating intention tremor by weighting the affected limb. Brain 95:579–590; 1972.PubMedGoogle Scholar
  3. 3.
    Javidan, M.; Elek, J.; Prochazka, A. Tremor reduction by functional electrical stimulation. Neurology 40:369; 1990.Google Scholar
  4. 4.
    Lee, R.G.; Stein, R.B. Resetting of tremor by mechanical perturbations: A comparison of essential tremor and Parkinsonian tremor. Ann. Neurol. 10:523–531; 1981.CrossRefPubMedGoogle Scholar
  5. 5.
    Marsden, C.D. Origins of normal and pathological tremor. In: Findley, L.J.; Capildeo, R., eds. Movement disorders: Tremor. London: Macmillan; 1984: pp. 37–84.Google Scholar
  6. 6.
    Morrice, B.L.; Lee, R.G.; Becker, W.J.; White, D.G.; Hoffer, J.A. Viscous loading improves manual tracking accuracy in humans with cerebellar incoordination. Soc. Neurosci. Abstracts 13:1700; 1987.Google Scholar
  7. 7.
    Prochazka, A.; Elek, J.; Javidan, M. Attenuation of pathological tremors by functional electrical stimulation I: Method. Ann. Biomed. Eng. 20:205–224; 1992.PubMedGoogle Scholar
  8. 8.
    Prochazka, A.; Davis, L.; Gauthier, M. New intramuscular electrodes and microprocessor control of electrical stimulation to improve hemiparetic gait. Soc. Neurosci. Abstracts. 17:1468; 1991.Google Scholar
  9. 9.
    Rack, P.M.H.; Ross, H.F. The role of reflexes in the resting tremor of Parkinson's Disease. Brain 109:115–141; 1986.PubMedGoogle Scholar
  10. 10.
    Stein, R.B.; Prochazka, A.; Popovic, D.; Edamura, M.; Llewellyn, M.; Davis, L.A. Technology transfer and development for walking using functional electrical stimulation. In: D. Popovic, ed. Advances in external control of human extremities X. Belgrade: Yugoslav Committee for Electronics and Automation; 1990: pp. 161–176.Google Scholar

Copyright information

© Pergamon Press Ltd. 1992

Authors and Affiliations

  • Manouchehr Javidan
    • 1
  • Josef Elek
    • 2
  • Arthur Prochazka
    • 1
  1. 1.Divisions of Neurology and Neuroscience, Room 507, Heritage BuildingUniversity of AlbertaEdmontonCanada
  2. 2.Neurologische Klinik der Universität BonnGermany

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