Intermittent bilateral coherence in physiological and essential hand tremor

0474149 - FGÚ 2018 RIV IE eng J - Journal Article
Chakraborty, Soma - Kopecká, J. - Šprdlík, Otakar - Hoskovcová, M. - Ulmanová, O. - Růžička, E. - Zápotocký, Martin
Intermittent bilateral coherence in physiological and essential hand tremor.
Clinical Neurophysiology. Roč. 128, č. 4 (2017), s. 622-634. ISSN 1388-2457. E-ISSN 1872-8952
R&D Projects: GA ČR(CZ) GBP304/12/G069
Institutional support: RVO:67985823 ; RVO:67985556
Keywords : physiological tremor * essential tremor * bilateral coupling * coherence * ballistocardiac impulse * accelerometry * wavelet analysis
OECD category: Neurosciences (including psychophysiology; Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) (UTIA-B)
Impact factor: 3.614, year: 2017

We investigated the prevalence and the temporal structure of bilateral coherence in physiological (PT) and essential (ET) hand tremor. Triaxial accelerometric recordings from both hands in 30 healthy subjects and 34 ET patients were analyzed using spectral coherence and wavelet coherence methods. In 12 additional healthy subjects, the relation between the hand tremor and the chest wall acceleration was evaluated using partial coherence analysis. The majority of both PT and ET subjects displayed significant bilateral coherence. While in PT, bilateral coherence was most frequently found in resting hand position (97% of subjects), in ET the prevalence was comparable for resting (54%) and postural (49%–57%) positions. In both PT and ET, epochs of strong coherence lasting several to a dozen seconds were separated by intervals of insignificant coherence. In PT, bilateral coherence at the main tremor frequency (8–12 Hz) was coupled with the ballistocardiac rhythm. The oscillations of the two hands are intermittently synchronized in both PT and ET. We propose that in postural PT, bilateral coherence at the main tremor frequency arises from transient simultaneous entrainment of the left and right hand oscillations to ballistocardiac forcing. Bilateral coherence of hand kinematics provides a sensitive measure of synchronizing influences on the left and right tremor oscillators.
Permanent Link: http://hdl.handle.net/11104/0271260