Abstract
Essential tremor and Parkinson’s disease cause abnormal oscillatory activity in a variety of brain structures that is transmitted to spinal motoneurons and generates tremor. Because the motoneuron pool integrates synaptic inputs from descending and spinal circuits, the decoding of its activity provides a view on all the neural pathways involved in tremor generation. We investigated tremor mechanisms by analyzing the behavior of populations of motoneurons within a single muscle, across antagonist muscle pairs, and in relation to cortical activity. We observed that tremor is caused by a common cortical input projected to all motoneurons. We also found that spinal reflex pathways contribute fundamentally to shaping tremor properties. We posit that although ET and PD tremor are centrally generated, tremor properties are strongly determined by the interaction between descending and afferent inputs to the motoneuron pool.
J.A. Gallego received funding from the EU Commission (FP7-PEOPLE-2013-IOF-627384).
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References
R.C. Helmich, I. Toni, G. Deuschl, B.R. Bloem, The pathophysiology of essential tremor and Parkinson’s tremor. Curr. Neurol. Neurosci. Rep. 13(9), 378 (2013)
C.J. Heckman, R.M. Enoka, Motor unit. Compr. Physiol. 2(4), 2629–2682 (2012)
D. Farina, R. Merletti, R.M. Enoka, The extraction of neural strategies from the surface EMG: an update. J. Appl. Physiol. 49 (2014)
D. Farina, A. Holobar, Characterization of human motor units from surface EMG decomposition. Proc. IEEE 104(2), 353–373 (2016)
F. Negro, D. Farina, Factors influencing the estimates of correlation between motor unit activities in humans. PLoS One 7(9), e44894 (2012)
J.A. Gallego, J.L. Dideriksen, A. Holobar, J. Ibáñez et al., Influence of common synaptic input to motor neurons on the neural drive to muscle in ET. J. Neurophysiol. 113, 182–191 (2015)
C.N. Christakos, S. Erimaki, E. Anagnostou, D. Anastasopoulos, Tremor-related motor unit firing in Parkinson’s disease: implications for tremor genesis. J. Physiol. 587, 4811–4827 (2009)
J.M. Elek, R. Dengler et al., Mechanical implications of paired motor unit discharges in pathological and voluntary tremor. Electroencephalogr. Clin. Neurophysiol. 81, 279–283 (1991)
A. Das Gupta, Paired response of motor units during voluntary contraction in Parkinsonism. J. Neurol. Neurosurg. Psychiatry 26, 265–268 (1963)
M. Muthuraman, A. Hossen, U. Heute, G. Deuschl, J. Raethjen, A new diagnostic test to distinguish tremulous Parkinson’s disease from advanced ET. Mov. Disord. 26, 1548–1552 (2011)
J.L. Dideriksen, J.A. Gallego, A. Holobar, E. Rocon et al., One central oscillatory drive is compatible with experimental motor unit behaviour in essential and Parkinsonian tremor. J. Neural Eng. 12, 046019 (2015)
F. Negro, D. Farina, Linear transmission of cortical oscillations to the neural drive to muscles is mediated by common projections to populations of motoneurons in humans. J. Physiol. 589(Pt 3), 629–637 (2011)
J.A. Gallego, J.L. Dideriksen, A. Holobar, J. Ibanez et al., The phase difference between neural drives to antagonist muscles in ET is associated with the relative strength of supraspinal and afferent input. J. Neurosci. 35, 8925–8937 (2015)
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Gallego, J.A., Dideriksen, J.L., Holobar, A., Rocon, E., Pons, J.L., Farina, D. (2017). Neural Control of Muscles in Tremor Patients. In: Ibáñez, J., González-Vargas, J., Azorín, J., Akay, M., Pons, J. (eds) Converging Clinical and Engineering Research on Neurorehabilitation II. Biosystems & Biorobotics, vol 15. Springer, Cham. https://doi.org/10.1007/978-3-319-46669-9_24
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DOI: https://doi.org/10.1007/978-3-319-46669-9_24
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