One central oscillatory drive is compatible with experimental motor unit behaviour in essential and Parkinsonian tremor

Dideriksen, Jacob L. and Gallego Juárez, Juan Antonio and Holobar, Ales and Rocón de Lima, Eduardo and Pons Rovira, José Luis and Farina, Darío (2015). One central oscillatory drive is compatible with experimental motor unit behaviour in essential and Parkinsonian tremor. "Journal of neural engineering" (n. 12); pp. 1-17. ISSN 1741-2560. https://doi.org/10.1088/1741-2560/12/4/046019.

Description

Title: One central oscillatory drive is compatible with experimental motor unit behaviour in essential and Parkinsonian tremor
Author/s:
  • Dideriksen, Jacob L.
  • Gallego Juárez, Juan Antonio
  • Holobar, Ales
  • Rocón de Lima, Eduardo
  • Pons Rovira, José Luis
  • Farina, Darío
Item Type: Article
Título de Revista/Publicación: Journal of neural engineering
Date: 10 June 2015
ISSN: 1741-2560
Subjects:
Freetext Keywords: pathological tremor, neural drive, motor unit
Faculty: Centro de Automática y Robótica (CAR) UPM-CSIC
Department: Otro
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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Abstract

Pathological tremors are symptomatic to several neurological disorders that are difficult to differentiate and the way by which central oscillatory networks entrain tremorogenic contractions is unknown. We considered the alternative hypotheses that tremor arises from one oscillator (at the tremor frequency) or, as suggested by recent findings from the superimposition of two separate inputs (at the tremor frequency and twice that frequency). Approach. Assuming one central oscillatory network we estimated analytically the relative amplitude of the harmonics of the tremor frequency in the motor neuron output for different temporal behaviors of the oscillator. Next, we analyzed the bias in the relative harmonics amplitude introduced by superimposing oscillations at twice the tremor frequency. These findings were validated using experimental measurements of wrist angular velocity and surface electromyography (EMG) from 22 patients (11 essential tremor, 11 Parkinson’s disease). The ensemble motor unit action potential trains identified from the EMG represented the neural drive to the muscles. Main results. The analytical results showed that the relative power of the tremor harmonics in the analytical models of the neural drive was determined by the variability and duration of the tremor bursts and the presence of the second oscillator biased this power towards higher values. The experimental findings accurately matched the analytical model assuming one oscillator, indicating a negligible functional role of secondary oscillatory inputs. Furthermore, a significant difference in the relative power of harmonics in the neural drive was found across the patient groups, suggesting a diagnostic value of this measure (classification accuracy: 86%). This diagnostic power decreased substantially when estimated from limb acceleration or the EMG. Signficance. The results indicate that the neural drive in pathological tremor is compatible with one central network providing neural oscillations at the tremor frequency. Moreover, the regularity of this neural oscillation varies across tremor pathologies, making the relative amplitude of tremor harmonics a potential biomarker for diagnostic use.

More information

Item ID: 43642
DC Identifier: http://oa.upm.es/43642/
OAI Identifier: oai:oa.upm.es:43642
DOI: 10.1088/1741-2560/12/4/046019
Official URL: https://iopscience.iop.org/article/10.1088/1741-2560/12/4/046019/meta
Deposited by: Memoria Investigacion
Deposited on: 03 Apr 2017 16:36
Last Modified: 10 Jun 2019 12:59
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