Abstract
This study proposes and clinically tests intramuscular electrical stimulation below motor threshold to achieve prolonged reduction of wrist flexion/extension tremor in Essential Tremor (ET) patients. The developed system consisted of an intramuscular thin-film electrode structure that included both stimulation and electromyography (EMG) recording electrodes, and a control algorithm for the timing of intramuscular stimulation based on EMG (closed-loop stimulation). Data were recorded from nine ET patients with wrist flexion/extension tremor recruited from the Gregorio Marañón Hospital (Madrid, Spain). Patients participated in two experimental sessions comprising: 1) sensory stimulation of wrist flexors/extensors via thin-film multichannel intramuscular electrodes; and 2) surface stimulation of the nerves innervating the same target muscles. For each session, four of these patients underwent random 60-s trials of two stimulation strategies for each target muscle: 1) selective and adaptive timely stimulation (SATS) - based on EMG of the antagonist muscle; and 2) continuous stimulation (CON) of target muscles. Two patients underwent SATS stimulation trials alone while the other three underwent CON stimulation trials alone in each session. Kinematics of wrist, elbow, and shoulder, together with clinical scales, were used to assess tremor before, right after, and 24 h after each session. Intramuscular SATS achieved, on average, 32% acute (during stimulation) tremor reduction on each trial, while continuous stimulation augmented tremorgenic activity. Furthermore, tremor reduction was significantly higher using intramuscular than surface stimulation. Prolonged reduction of tremor amplitude (24 h after the experiment) was observed in four patients. These results showed acute and prolonged (24 h) tremor reduction using a minimally invasive neurostimulation technology based on SATS of primary sensory afferents of wrist muscles. This strategy might open the possibility of an alternative therapeutic approach for ET patients.
| Original language | English (US) |
|---|---|
| Article number | 9171555 |
| Pages (from-to) | 1768-1776 |
| Number of pages | 9 |
| Journal | IEEE Transactions on Biomedical Engineering |
| Volume | 68 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2021 |
Funding
This work was supported in part by the European Union?s Horizon 2020 research and innovation programme (Project EXTEND?Bidirectional Hyper-Connected Neural System) under Grant 779982 and in part by the Spanish National Research Council, through the Project ?Smart? under Grant 202020E121. Manuscript received June 10, 2020; revised July 29, 2020; accepted August 3, 2020. Date of publication August 19, 2020; date of current version May 20, 2021. This work was supported in part by the European Union\u2019s Horizon 2020 research and innovation programme (Project EXTEND\u2014Bidirectional Hyper-Connected Neural System) under Grant 779982 and in part by the Spanish National Research Council, through the Project \u201CSmart\u201D under Grant 202020E121. (Dario Farina, Jos\u00E9 Luis Pons and Filipe Oliveira Barroso contributed equally to this work.) (Corresponding author: Filipe Oliveira Barroso.) Alejandro Pascual-Valdunciel is with the Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC) and also with the E.T.S. Ingenieros de Telecomunicaci\u00F3n, Universidad Polit\u00E9cnica de Madrid.
Keywords
- Essential tremor
- Intramuscular
- Neuromodulation
- Sensory stimulation
- Tremor reduction
ASJC Scopus subject areas
- Biomedical Engineering