Tongue shear wave elastography for bulbar dysfunction in amyotrophic lateral sclerosis.

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) often manifests with tongue involvement, leading to dysarthria and dysphagia. While current diagnostic methods are invasive or qualitative, the development of non-invasive quantitative assessments of tongue function is essential.

METHODS

A prospective study (March 2022 - March 2024) included 38 ALS patients (categorized by bulbar or spinal onset) and 12 controls. Clinical symptoms were evaluated using the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R). Tongue muscle elasticity was measured using shear wave elastography (LOGIQ® E9, 9 MHz).

RESULTS

Median shear modulus of the genioglossus (GG) muscle was significantly lower in bulbar-onset ALS (7.80 kPa, range 5.41-10.08) compared to spinal-onset ALS (12.48 kPa, range 8.50-21.42) and controls (14.16 kPa, range 11.37-20.21). The geniohyoid (GH) muscle showed similar patterns. Both muscles showed significantly reduced elasticity in bulbar-onset ALS compared to controls (p < 0.05). The GG muscle elasticity showed strong positive correlation with bulbar symptom severity on the ALSFRS-R.

CONCLUSIONS

Reduced tongue muscle elasticity in bulbar-onset ALS, along with its correlation with bulbar symptoms, suggests the potential utility of this technique for both diagnosis and prognosis.

SIGNATURE: These findings indicate that shear wave elastography is a promising noninvasive tool for the quantitative assessment of tongue dysfunction in ALS.