Category: Tremor
Objective: The main aim of the study was to investigate asymmetry in ET and the association between tremor asymmetry and the effect of DBS on tremor.
Background: Tremor phase-locked deep brain stimulation (DBS) has been shown to modulate tremor severity in patients with essential (ET) and dystonic tremor, providing a potential therapy alternative with less energy delivered to the brain. Previous phase-locked DBS studies focused on evaluating the effect of unilateral stimulation on the tremor-dominant hand. Considering asymmetric properties of ET, it remains unknown whether bilateral phase-locked DBS will provide additional benefits regarding tremor suppression.
Method: Limb acceleration and thalamic local field potentials (LFPs) recorded from 14 ET patients were analysed to investigate the asymmetry in tremor amplitude, frequency, and stability, and their association with the effect of continuous DBS on tremor. The coherence (non-directional and directional) between thalamic LFPs and limb acceleration was quantified as patients held a tremor provoking posture. We then compared the contralateral vs. ipsilateral LFP-limb connectivity pairs. Lastly, bilateral phase-locked DBS was tested in two patients with chronically implanted DBS devices.
Results: Our results showed that ET was asymmetric in terms of tremor amplitude, stability, and peak tremor frequency. These properties were modulated by continuous high frequency DBS. Tremor amplitude during no DBS positively (r = 0.7104, p = 3.3055e-05, N = 27) while tremor stability index during no DBS negatively (r = -0.4343, p = 0.0236, N = 27) correlated with the change in tremor amplitude during continuous DBS. Directional coherence from thalamic LFPs recorded from the contralateral hemisphere to limb tremor was stronger than from the ipsilateral hemisphere (p = 0.0358, N = 23). We also observed that the phase-locked DBS effect was asymmetric.
Conclusion: By creating a better understanding of tremor asymmetry and its relationship with DBS, this study provides important insights for the development of patient specific therapeutic approaches for ET.
To cite this abstract in AMA style:
S. He, A. Deli, T. West, F. Plazas, A. Pogosyan, C. Wiest, D. Herz, P. Andrade, V. Visser-Vandewalle, E. Pereira, A. Green, H. Tan, H. Cagnan. Asymmetry and the development of phase-specific deep brain stimulation for essential tremor [abstract]. Mov Disord. 2023; 38 (suppl 1). https://www.mdsabstracts.org/abstract/asymmetry-and-the-development-of-phase-specific-deep-brain-stimulation-for-essential-tremor/. Accessed June 15, 2025.« Back to 2023 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/asymmetry-and-the-development-of-phase-specific-deep-brain-stimulation-for-essential-tremor/