Tongue thickness evaluation using ultrasonography can predict swallowing function in amyotrophic lateral sclerosis patients

Dysphagia is a critical issue in amyotrophic lateral sclerosis (ALS) patients. An evaluation of swallowing function is important for assessing the risk of aspiration. We investigated the validity of tongue sonography compared with videofluoroscopic examination for ALS patients.We investigated 18 ALS patients. Nine subjects underwent repeated investigations. All of the subjects underwent tongue sonography and videofluoroscopic examination. Additionally, tongue sonography was evaluated in 18 age- and sex-matched healthy volunteers. To determine tongue thickness, we measured the vertical distance from the surface of the mylohyoid muscle to the tongue dorsum using ultrasonography.In the ALS patients, the tongue was significantly thinner than in healthy subjects. Tongue thickness was associated with body mass index and onset type in the ALS patients (p=0.006). Temporal analyses of videofluoroscopy revealed that tongue thickness was associated with oral preparatory and transit time (p=0.032) but not with pharyngeal transit time. Repeated measurement data revealed a decrease in tongue thickness over the course of the measurements (p=0.002).In ALS patients, reduced tongue thickness suggests disease progression and tongue dysfunction.Tongue sonography is a useful modality for the non-invasive and quantitative evaluation of tongue thickness and dysphagia in ALS patients.