Skip to main content
PMC home page
Journal of Neurology, Neurosurgery, and Psychiatry logoLink to Journal of Neurology, Neurosurgery, and Psychiatry
. 1998 Jan;64(1):33–36. doi: 10.1136/jnnp.64.1.33

Modulation of primary orthostatic tremor by magnetic stimulation over the motor cortex

C Tsai 1, J Semmler 1, T Kimber 1, G Thickbroom 1, R Stell 1, F Mastaglia 1, P Thompson 1
PMCID: PMC2169891  PMID: 9436724

Abstract

OBJECTIVES—To study the role of corticomotor neuronal pathways in primary orthostatic tremor.
METHODS—Transcranial magnetic stimuli at an intensity 10% above the resting motor threshold were delivered over the leg motor cortex in two patients with primary orthostatic tremor while standing still. Electromyographic responses in both tibialis anterior muscles were recorded after 20 stimuli given randomly at intervals of 120 to 180 seconds. Differences between predicted and actual times of occurrence of tremor bursts after the stimuli were used to calculate a resetting index, with a value of 0 representing no resetting and a value of 1 representing complete resetting.
RESULTS—Transcranial magnetic stimulation evoked EMG responses in both tibialis anterior muscles, followed by transient suppression of tremor before reappearance of rhythmic EMG activity. Analysis of the timing of tremor bursts from EMG recordings before and after the magnetic stimuli disclosed that the phase of orthostatic tremor could be reset by brain stimulation (mean resetting indices 0.93 and 0.82).
CONCLUSION—The results suggest that a central oscillator, involving the motor cortex, has a crucial role in either the generation or modulation of orthostatic tremor.



Full Text

The Full Text of this article is available as a PDF (102.4 KB).

Selected References

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

  1. Britton T. C., Thompson P. D., Day B. L., Rothwell J. C., Findley L. J., Marsden C. D. "Resetting" of postural tremors at the wrist with mechanical stretches in Parkinson's disease, essential tremor, and normal subjects mimicking tremor. Ann Neurol. 1992 May;31(5):507–514. doi: 10.1002/ana.410310508. [DOI] [PubMed] [Google Scholar]
  2. Britton T. C., Thompson P. D., Day B. L., Rothwell J. C., Findley L. J., Marsden C. D. Modulation of postural wrist tremors by magnetic stimulation of the motor cortex in patients with Parkinson's disease or essential tremor and in normal subjects mimicking tremor. Ann Neurol. 1993 May;33(5):473–479. doi: 10.1002/ana.410330510. [DOI] [PubMed] [Google Scholar]
  3. Britton T. C., Thompson P. D., van der Kamp W., Rothwell J. C., Day B. L., Findley L. J., Marsden C. D. Primary orthostatic tremor: further observations in six cases. J Neurol. 1992 Apr;239(4):209–217. doi: 10.1007/BF00839142. [DOI] [PubMed] [Google Scholar]
  4. Gabellini A. S., Martinelli P., Gullì M. R., Ambrosetto G., Ciucci G., Lugaresi E. Orthostatic tremor: essential and symptomatic cases. Acta Neurol Scand. 1990 Feb;81(2):113–117. doi: 10.1111/j.1600-0404.1990.tb00944.x. [DOI] [PubMed] [Google Scholar]
  5. 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]
  6. Papa S. M., Gershanik O. S. Orthostatic tremor: an essential tremor variant? Mov Disord. 1988;3(2):97–108. doi: 10.1002/mds.870030201. [DOI] [PubMed] [Google Scholar]
  7. Pascual-Leone A., Valls-Solé J., Toro C., Wassermann E. M., Hallett M. Resetting of essential tremor and postural tremor in Parkinson's disease with transcranial magnetic stimulation. Muscle Nerve. 1994 Jul;17(7):800–807. doi: 10.1002/mus.880170716. [DOI] [PubMed] [Google Scholar]
  8. Thompson P. D., Rothwell J. C., Day B. L., Berardelli A., Dick J. P., Kachi T., Marsden C. D. The physiology of orthostatic tremor. Arch Neurol. 1986 Jun;43(6):584–587. doi: 10.1001/archneur.1986.00520060048016. [DOI] [PubMed] [Google Scholar]
  9. Uncini A., Onofrj M., Basciani M., Cutarella R., Gambi D. Orthostatic tremor: report of two cases and an electrophysiological study. Acta Neurol Scand. 1989 Feb;79(2):119–122. doi: 10.1111/j.1600-0404.1989.tb03722.x. [DOI] [PubMed] [Google Scholar]
  10. Volkmann J., Joliot M., Mogilner A., Ioannides A. A., Lado F., Fazzini E., Ribary U., Llinás R. Central motor loop oscillations in parkinsonian resting tremor revealed by magnetoencephalography. Neurology. 1996 May;46(5):1359–1370. doi: 10.1212/wnl.46.5.1359. [DOI] [PubMed] [Google Scholar]
  11. Wills A. J., Thompson P. D., Findley L. J., Brooks D. J. A positron emission tomography study of primary orthostatic tremor. Neurology. 1996 Mar;46(3):747–752. doi: 10.1212/wnl.46.3.747. [DOI] [PubMed] [Google Scholar]

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

RESOURCES