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

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.

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.