Skip to main content
PMC home page
Journal of Neurology, Neurosurgery, and Psychiatry logoLink to Journal of Neurology, Neurosurgery, and Psychiatry
. 1987 May;50(5):568–579. doi: 10.1136/jnnp.50.5.568

Differential effects of changes in mechanical limb properties on physiological and pathological tremor.

V Hömberg, H Hefter, K Reiners, H J Freund
PMCID: PMC1031968  PMID: 3585382

Abstract

The effect of changes in mechanical limb properties on the peak frequency of different tremor forms was analysed. Wrist tremor was recorded by an accelerometer fixed to the dorsum of the hand and demodulated surface EMG was recorded from the wrist extensors, while the extended hand was loaded with successively heavier weights. Physiological tremor was characterised by flat EMG spectra and a gradual decrease in tremor peak frequency with increasing load, as would be expected from the properties of a passive spring-mass-system. Also the peak frequency of activated physiological tremor characterised by increased synchronisation between motor units decreased in frequency with increasing loads. EMG spectra showed clear peaks of activity at the various mechanically determined tremor frequencies. In contrast, in two pathological tremor forms, the postural tremor in Parkinsonian patients and essential tremor, peak frequency tended to remain stable irrespective of changes in load. The method therefore allows a simple distinction between physiological and these two pathological tremors.

Full text

PDF
571

Selected References

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

  1. Allum J. H., Dietz V., Freund H. J. Neuronal mechanisms underlying physiological tremor. J Neurophysiol. 1978 May;41(3):557–571. doi: 10.1152/jn.1978.41.3.557. [DOI] [PubMed] [Google Scholar]
  2. Elble R. J. Physiologic and essential tremor. Neurology. 1986 Feb;36(2):225–231. doi: 10.1212/wnl.36.2.225. [DOI] [PubMed] [Google Scholar]
  3. Hagbarth K. E., Wallin G., Löfstedt L., Aquilonius S. M. Muscle spindle activity in alternating tremor of Parkinsonism and in clonus. J Neurol Neurosurg Psychiatry. 1975 Jul;38(7):636–641. doi: 10.1136/jnnp.38.7.636. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Hagbarth K. E., Young R. R. Participation of the stretch reflex in human physiological tremor. Brain. 1979 Sep;102(3):509–526. doi: 10.1093/brain/102.3.509. [DOI] [PubMed] [Google Scholar]
  5. Hömberg V., Reiners K., Hefter H., Freund H. J. The muscle activity spectrum: spectral analysis of muscle force as an estimator of overall motor unit activity. Electroencephalogr Clin Neurophysiol. 1986 Mar;63(3):209–222. doi: 10.1016/0013-4694(86)90087-8. [DOI] [PubMed] [Google Scholar]
  6. Lee R. G., Stein R. B. Resetting of tremor by mechanical perturbations: a comparison of essential tremor and parkinsonian tremor. Ann Neurol. 1981 Dec;10(6):523–531. doi: 10.1002/ana.410100606. [DOI] [PubMed] [Google Scholar]
  7. Matthews P. B., Muir R. B. Comparison of electromyogram spectra with force spectra during human elbow tremor. J Physiol. 1980 May;302:427–441. doi: 10.1113/jphysiol.1980.sp013254. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Oğuztöreli M. N., Stein R. B. The effects of multiple reflex pathways on the oscillations in neuro-muscular systems. J Math Biol. 1976 Apr 29;3(1):87–101. doi: 10.1007/BF00307860. [DOI] [PubMed] [Google Scholar]
  9. Rack P. M., Ross H. F. The role of reflexes in the resting tremor of Parkinson's disease. Brain. 1986 Feb;109(Pt 1):115–141. doi: 10.1093/brain/109.1.115. [DOI] [PubMed] [Google Scholar]
  10. Sabra A. F., Hallett M. Action tremor with alternating activity in antagonist muscles. Neurology. 1984 Feb;34(2):151–156. doi: 10.1212/wnl.34.2.151. [DOI] [PubMed] [Google Scholar]
  11. Shahani B. T., Young R. R. Physiological and pharmacological aids in the differential diagnosis of tremor. J Neurol Neurosurg Psychiatry. 1976 Aug;39(8):772–783. doi: 10.1136/jnnp.39.8.772. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Stiles R. N., Pozos R. S. A mechanical-reflex oscillator hypothesis for parkinsonian hand tremor. J Appl Physiol. 1976 Jun;40(6):990–998. doi: 10.1152/jappl.1976.40.6.990. [DOI] [PubMed] [Google Scholar]
  13. Stiles R. N., Randall J. E. Mechanical factors in human tremor frequency. J Appl Physiol. 1967 Sep;23(3):324–330. doi: 10.1152/jappl.1967.23.3.324. [DOI] [PubMed] [Google Scholar]
  14. Vilis T., Hore J. Effects of changes in mechanical state of limb on cerebellar intention tremor. J Neurophysiol. 1977 Sep;40(5):1214–1224. doi: 10.1152/jn.1977.40.5.1214. [DOI] [PubMed] [Google Scholar]
  15. Walsh E. G. Beats produced between a rhythmic applied force and the resting tremor of Parkinsonism. J Neurol Neurosurg Psychiatry. 1979 Jan;42(1):89–94. doi: 10.1136/jnnp.42.1.89. [DOI] [PMC free article] [PubMed] [Google Scholar]

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

RESOURCES