Work

Ultrasound Assessment of the Diaphragm Across Neuromuscular Diseases

Year: 2026

Type: article

Abstract: Background and Purpose Despite its utility in certain neuromuscular disorders, the exact role of diaphragmatic ultrasound in the workup of Myasthenia Gravis (MG) and other neuromuscular disorders is not well‐understood. We aimed to characterize this technique in MG and other neuromuscular patients, according to specific pathology. Methods We recruited 143 subjects for this prospective study at the University Health Network (UHN) between October 2021 and September 2025. Patients were categorized into nine different neuromuscular disease groups, of which the largest was the MG group with 50 patients. Bilateral diaphragmatic ultrasound was performed with thickness measurements at baseline and end‐of deep inspiration. Results Baseline thickness in the control group was 0.251 ± 0.066 cm. Reduced baseline thickness was found in generalized autoimmune MG (0.219 ± 0.062 cm, p = 0.001), and also in other groups such as hereditary (but not inflammatory) myopathies and all types of polyneuropathies, except for the axonal. Thickness at end‐of‐deep inspiration and thickening ratio were both significantly reduced, compared to the control group, in the generalized autoimmune MG ( p <0.01), and other neuromuscular disease groups. MG patients with breathing difficulties had a significantly reduced inspiration thickness ( p = 0.04) and thickening ratio ( p = 0.008) compared to patients with no breathing problems. Conclusions Our study suggests that generalized MG is associated with a structural as well as functional diaphragmatic deficit, based on ultrasound findings. The study supports the use of diaphragmatic US as a helpful complementary technique in the evaluation of MG and possibly other neuromuscular patients with breathing difficulties.

Source: Clinical neuroimaging.

DOI: 10.1002/neo2.70070