Transcutaneous Superior Laryngeal Nerve Stimulation to Upregulate Swallowing Frequency and Urge to Swallow in Patients Living With ALS

Overview

Prospective, single-arm pilot study evaluating transcutaneous electrical nerve stimulation of the superior laryngeal nerve (TENS-SLN) in individuals with ALS. Up to 5 participants with confirmed ALS and bulbar involvement will be enrolled. Primary outcomes: swallowing frequency and perceived urge to swallow. Participants complete a baseline visit, followed by two supervised treatment sessions within one week, and a final post-treatment evaluation. Optional visits (up to 2) may be used to individualize stimulation parameters prior to treatment. Swallowing function will be assessed using physiological monitoring, fiberoptic endoscopy, and videofluoroscopic swallow study (VFSS). TENS-SLN is a non-invasive neuromodulation approach targeting sensory pathways to facilitate swallowing without inducing muscle contraction. This pilot study is designed to assess feasibility, safety, and preliminary effect sizes to inform future randomized trials, and is not powered to determine efficacy.

Detailed description

This prospective, single-arm interventional pilot study will evaluate the acute effects of transcutaneous electrical nerve stimulation of the superior laryngeal nerve (TENS-SLN) on swallowing function in individuals with amyotrophic lateral sclerosis (ALS). Up to five participants with confirmed ALS and bulbar involvement will be enrolled. The primary outcomes are swallowing frequency and perceived urge to swallow.

Participants will complete a baseline assessment followed by two supervised TENS-SLN treatment sessions conducted within a one-week period. Up to two additional visits may be performed prior to treatment to optimize individualized stimulation parameters. Treatment sessions may take place in the clinic or the participant's home under clinician supervision. A final in-clinic evaluation will be completed at the end of the study period. Swallowing function will be assessed using physiological monitoring, fiberoptic endoscopy, and videofluoroscopic swallow study (VFSS) at baseline and post-intervention.

TENS-SLN is a non-invasive neuromodulation approach that delivers low-intensity electrical stimulation via surface electrodes placed over the anatomically accessible superior laryngeal nerve in the anterior neck. The intervention is designed to enhance sensory input to swallowing-related neural circuits and facilitate swallow initiation without directly eliciting muscle contraction.

This pilot study is not powered to determine efficacy but is intended to assess feasibility, safety, and preliminary effect sizes to inform the design of future randomized controlled trials. All study procedures are performed for research purposes and are not part of standard clinical care.

Interventions

• Other Transcutaneous Superior Laryngeal Nerve Stimulation to Upregulate Swallowing Frequency and Urge to Swallow
  Transcutaneous Superior Laryngeal Nerve Stimulation to Upregulate Swallowing Frequency and Urge to Swallow in ALS

Primary outcome measures

• Swallowing Frequency [Time frame: From enrollment to the end of the 7-day follow-up period]
• Urge-to-swallow [Time frame: Measured from enrollment to the end of the 7 day follow up period]

Secondary outcome measures (7)

• Body weight gain/loss [Time frame: At Day 1 and at Day 7]
• Maximum Expiratory Pressure [Time frame: From enrollment to the end of the 7-day follow up period]
• Lingual pressure assessment [Time frame: At baseline (Day 1) pre-procedural, on Day 1 post-procedure, and on Day 7]
• Peak cough flow [Time frame: One at enrollment and one at the end of the 7- day folow-up period]
• Videofluoroscopic Swallowing Evaluation [Time frame: At baseline and at the end of the 7-day follow-up period]
• Fiberoptic Endoscopic Evaluation of Swallowing (FEES) [Time frame: At baseline and again at the end of the 7 day follow up period]
• Body Weight (BMI) [Time frame: Day 1 - Day 7]

Eligibility criteria

Inclusion criteria

• Confirmed diagnosis of ALS (El-Escorial Criteria)
• ALS FRS Bulbar Subscore of ≤ 10 and ≥ 3.
• Functional Oral Intake scale score ≥ 2

Exclusion criteria

• A diagnosis of significant cognitive impairment or frontotemporal dementia per the treating neurologist or neuropsychologist,
• Current nasogastric tube placement
• Current head and neck carcinoma
• Pacemaker or implanted defibrillator or history of diagnosed arrhythmia, bradycardia, or repeated attacks of hypotension,
• Implanted vagal nerve stimulator
• Current pregnancy
• History of epilepsy
• Infected, broken or inflamed skin on the neck, or impaired sensation at the site of sEMG or TENS placement
• Living greater than 50 miles from the NSU clinic round trip
• Any clinical reason that this stimulation may not be a suitable treatment according to the principal investigator.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Publications

• Tabor LC, Rosado KM, Robison R, Hegland K, Humbert IA, Plowman EK. Respiratory training in an individual with amyotrophic lateral sclerosis. Ann Clin Transl Neurol. 2016 Sep 1;3(10):819-823. doi: 10.1002/acn3.342. eCollection 2016 Oct. PMID 27752517
• Tabor Gray, L., Locatelli, E., Vasilopoulos T., Wymer, J., Plowman, EK. (2022). Impact of Nuedexta on Bulbar Function and Physiology. Muscle and Nerve, 66(S2), S1-S63. https://doi.org/https://doi.org/10.1002/mus.27729
• Robison R, Tabor-Gray LC, Wymer JP, Plowman EK. Combined respiratory training in an individual with C9orf72 amyotrophic lateral sclerosis. Ann Clin Transl Neurol. 2018 Aug 21;5(9):1134-1138. doi: 10.1002/acn3.623. eCollection 2018 Sep. PMID 30250869
• Plowman EK, Watts SA, Tabor L, Robison R, Gaziano J, Domer AS, Richter J, Vu T, Gooch C. Impact of expiratory strength training in amyotrophic lateral sclerosis. Muscle Nerve. 2016 Jun;54(1):48-53. doi: 10.1002/mus.24990. Epub 2016 Mar 3. PMID 26599236
• Plowman EK, Tabor-Gray L, Rosado KM, Vasilopoulos T, Robison R, Chapin JL, Gaziano J, Vu T, Gooch C. Impact of expiratory strength training in amyotrophic lateral sclerosis: Results of a randomized, sham-controlled trial. Muscle Nerve. 2019 Jan;59(1):40-46. doi: 10.1002/mus.26292. Epub 2018 Nov 29. PMID 29981250
• Plowman EK, Gray LT, Chapin J, Anderson A, Vasilopoulos T, Gooch C, Vu T, Wymer JP. Respiratory Strength Training in Amyotrophic Lateral Sclerosis: A Double-Blind, Randomized, Multicenter, Sham-Controlled Trial. Neurology. 2023 Apr 11;100(15):e1634-e1642. doi: 10.1212/WNL.0000000000206830. Epub 2023 Feb 20. PMID 36805435
• Ballenger, B., Barry, E., Wang, J., Haxton, C., Deninger, I., Thompson, R., Osman, K. L., & Lever, T. E. (2022). Targeted Electrical Stimulation of the Superior Laryngeal Nerve - A Potential Treatment for Dysphagia in ALS. The FASEB Journal, 36(S1). https://doi.org/https://doi.org/10.1096/fasebj.2022.36.S1.R4239

Identifiers

NCT: NCT07606235 · 2026-127-NSU

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗