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Introduction Motor neurone disease (MND) is a progressive neurodegenerative disorder affecting motor neurones in the cortex, brainstem, and spinal cord. In advanced stages, it leads to sleep-disordered breathing, respiratory failure, and bulbar symptoms. We sought to visualise the contraction of the upper airway dilator muscles using ultrasound while applying transcutaneous electrical stimulation (TES) in the submental area.Methods A case-control study was conducted involving patients with MND and healthy controls( NCT03160456). TES was delivered using a dual-channel stimulator (Premier Combo Plus EM-6300A, Everyway Medical Instruments, Taiwan) set at 30 Hz and 250 µs pulse width. Electrical current was individually titrated to a tolerable level of comfort. Stimulation was applied using 4×4 cm electrodes placed bilaterally in the submental region.Ultrasound imaging was performed with a Venue system (GE Healthcare, USA) and a GE 12L-RS linear probe (3.4–12.6 MHz). The transducer was positioned 2 cm behind the chin, pointing cranially to capture sagittal and coronal planes of the tongue base muscles, including the geniohyoid and the genioglossus. Measurements included sagittal and coronal muscle diameters and cross-sectional area (CSA) with TES-off and TES-on.Results 14 patients with MND (5 females, age 69±10 years; body mass index, BMI 26 ± 3 kg/m 2) and 11 healthy participants (4 females, age 34±8 years; BMI 23±3.6 kg/m2) were recruited. In the sagittal plane, MND patients showed an increase of 5.0 (2.8)% in the midline diameter and 5.6 (3)% in the widest diameter with TES (p<0.001, respectively). Healthy participants demonstrated similar increases of 3.9 (2.8)% for midline and 3.9 (2.9)% for the widest diameters(p < 0.001, respectively). In the coronal plane, the midline diameter increased by 3.9 (1.5)% in MND patients and 2.9 (2.2)% in healthy controls, while the cross-sectional area (CSA) increased by 7.23 (4.2)% and 3.8 (3)% (p<0.001, respectively). All parameters responded similarly between groups, except for coronal CSA, which showed a significant difference (p = 0.033).Conclusion TES can evoke contraction of the upper airway dilator muscles in MND patients, similar to what is observed in healthy volunteers. These findings may lead to early therapeutic interventional strategies aiming to preserve bulbar function in MND patients.