A Pilot Study Assessing Shear Wave Elastography’s Potential As A Biomarker in Spinal-Bulbar & Muscular Atrophy

Topic:

Clinical Trials

Poster Number: S115

Author(s):

Yonathan Assefa, Rehabilitation Medicine Department, National Institutes of Health, Euan Forrest, National Institutes of Health, Abdullah AlQahtani, MD, MPH, National Institutes of Health, Joseph Shrader, PT, National Institutes of Health, Henry Roberts, Statistician, Katharine Alter, MD, National Institutes of Health, Galen Joe, MD, National Institutes of Health, Mina Jain, PT, National Institutes of Health, Christopher Grunseich, MD, Neuromuscular and Neurogenetic Disorders of Childhood Section, NINDS, NIH

Background:

Spinal-bulbar muscular atrophy (SBMA) is a rare neuromuscular disorder caused by a CAG trinucleotide repeat in the androgen receptor gene. Currently, there are no approved disease-modifying treatments for SBMA. One challenge in developing therapies is the lack of sensitive biomarkers for tracking disease severity and progression. Shear Wave Elastography (SWE), an emerging ultrasonographic technology, offers a non-invasive way to quantify muscle tissue stiffness, potentially serving as a valuable biomarker for SBMA.

Objectives: To explore Shear Wave Elastography (SWE) as a biomarker of disease in SBMA.

Methods:

A cross-sectional study was conducted with data collected from 13 genetically confirmed SBMA patients. SWE measurements were obtained using a Samsung Prestige RS85 ultrasound machine, and six muscle points were examined for shear wave and velocity. Primary outcome measures included the Adult Myopathy Assessment Tool (AMAT), 6-minute walk test (6MWT), and creatinine levels. The participants were categorized into high-function (n=6) and impaired-function (n=7) groups based on AMAT scores.

Results:

The study revealed variable outcomes when comparing SWE means between high-function and impaired-function AMAT groups. Strong associations were found between AMAT subgroups, 6MWT performance, and elevated creatinine levels. However, SWE data did not show a significant relationship with these metrics. Notably, the masseter, rectus femoris, and tibialis anterior muscles in the impaired-function group exhibited higher shear wave and velocity, potentially indicating increased tissue stiffness associated with atrophy/dysfunction.

Conclusions:

The study suggests that Shear Wave Elastography (SWE) has potential as a biomarker in SBMA. However, the technology’s utility may be influenced by confounding factors such as heterogeneity of muscle involvement, variability of disease progression, patient cooperation, and operator skills. Further research with larger sample sizes is needed to definitively determine SWE’s capability to detect changes in SBMA severity and progression.