Postural finger tremor exhibited by Parkinson patients and age-matched subjects


  • Dr. Suzanne S. Palmer,

    Corresponding author
    1. Department of Physical Therapy, Texas Tech University Health Sciences Center, Texas, U.S.A.
    • Department of Physiology/Neuroscience, St. George's University School of Medicine, Grenada, West Indies
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  • J. Thomas Hutton

    1. Neurology Research and Education Center, St. Mary of the Plains Hospital, Lubbock, Texas, U.S.A.
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Physiological correlates of postural tremor of the finger seen in Parkinson's disease patients are different from those seen in age-matched control subjects. A significant correlation between the spectral peak of acceleration and the spectral peak of rectified electromyographic activity from the muscle responsible for finger extension was found in Parkinson's disease patients. This correlation was not seen in age-matched control subjects. Any neural drive imposed on the motoneuron pool from supraspinal levels would enhance the electromyographic activity. Likewise, any feedback effects via spinal stretch reflexes or supraspinal stretch responses would be mediated through the motoneuron pool and electromyographic activity. The results of this research support the theory that Parkinson tremor is a centrally driven rhythm that may be influenced by feedback effects, whereas physiological tremor is due to a complex interaction of central, feedback, and mechanical effects.