Abstract Details

Title Non-invasive Cervical Vagus Nerve Stimulation Improves Digital Spiral Tests in Essential Tremor: An Open Label Pilot Study

Topic Movement Disorders

Presentation(s) P1 - Poster Session 1 (11:45 AM-12:45 PM)

Poster/Presentation
Number 5-003

Objective To explore the potential benefit of non-invasive transcutaneous vagal nerve stimulation in treatment of essential tremor.

Background Essential tremor (ET) is the most common cause of action tremor, affecting ~1% of the global population. Medical treatments including propranolol and primidone are limited by dose-related side effects. Preliminary studies have revealed that implantable vagus nerve stimulation (VNS) improves kinematic ET parameters. However, the efficacy and tolerability is limited. Non-invasive options represent a promising alternative.

Design/Methods

Seventeen subjects (11 female, aged 66.2 ± 13.9 years, disease duration 18.5 ± 12.6 years) with essential tremor were recruited for a pilot study. All subjects were treated with 4 consecutive cycles of 25 Hz GammaCORE cVNS targeting the cervical portion of the left vagus nerve. Total Fahn-Tolosa-Marin scale (FTM) scores were collected before and after treatment. All subjects completed n=10 Archimedes spiral drawings using a digital spiral analysis platform, using both their dominant and non-dominant hands, before and after treatment. Four previously validated spiral metrics (spiral width variability index mean and standard, mean change in radian over change in time, and mean change in radian over change in angle) were collected. Data were analyzed using linear mixed models with subject as a random effect.

Results FTM score did not differ after stimulation (log(OR) = 0.03, 95% CI [-1.2,1.2]; ordinal logistic regression). Treatment was associated with significant decreases in spiral width variability indices and delta radian per delta time and delta angle (mean SWVI model: β, 95% CI = -1.4 [-2.0,-0.81]; standard deviation SWVI model: β, 95% CI = -7.3 [-10,-4.6]; mean Δr/Δθ model: β, 95% CI = -0.06 [-0.10,-0.02]; mean (Δr/Δt) model: β, 95% CI = -0.18 [-0.26,-0.10]; linear mixed effects models).

Conclusions

Treatment with non-invasive cVNS improved previously validated metrics for the analysis of Archimedes spirals. This pilot study highlights the potential benefit of non-invasive cVNS in ET.

Authors/Disclosures
Rogan Magee, MD, PhD (Penn Medicine) PRESENTER	Dr. Magee has nothing to disclose.
Massimo Marano, MD, PhD	Dr. Marano has nothing to disclose.
Francesca Blasi, MD	Dr. Blasi has nothing to disclose.
Gaia Anzini (Università Campus Bio-Medico di Roma)	No disclosure on file
Fioravante Capone, PhD	Dr. Capone has nothing to disclose.
Riccardo Antonio Ricciuti, Sr., MD	Dr. Ricciuti has nothing to disclose.
Matteo Maria Ottaviani, MD, PhD	Dr. Ottaviani has nothing to disclose.
Vincenzo Di Lazzaro, MD	Prof. Di Lazzaro has nothing to disclose.

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