Real-Time Ultrasound Elastography in Multiple Sclerosis Spasticity: Comparison with Clinical and Neurophysiological Measures.

Background

Spasticity is a common and disabling symptom of multiple sclerosis (MS), yet its assessment remains challenging. Clinical scales such as the Ashworth Scale (AS) evaluate resistance to passive movement, whereas neurophysiological measures (e.g., H-reflex, F-wave) provide objective indices of α-motoneuron excitability but correlate inconsistently with clinical severity. Real-time ultrasound elastography (RTE) enables semi-quantitative, in vivo assessment of muscle stiffness, while the recently introduced Muscle Elastography Multiple Sclerosis Score (MEMSs) aims to classify muscle spasticity in MS.

Objective

To evaluate the utility of RTE using MEMSs for the objective assessment of muscle status in MS patients with spasticity, and to compare elastographic findings with clinical and neurophysiological measures.

Methods

In this single-center study, 26 MS patients (diagnosed according to the 2017 McDonald criteria) and age- and sex-matched healthy controls (n = 27) were enrolled. Spasticity was graded using the AS. All participants underwent bilateral RTE of the gastrocnemius muscle, with images independently scored by two blinded neurologists using the 5-point MEMSs scale. Neurophysiological assessment included the soleus H-reflex, with calculation of H/M ratios. Correlations were analyzed using Pearson's coefficient, and inter-observer reliability was assessed.

Results

No consistent or statistically robust associations were found between clinical spasticity severity (AS scores) and either neurophysiological or elastographic parameters. Several MEMSs did not correlate reliably with AS grades, and neurophysiological measures showed limited discriminatory ability between MS patients and healthy controls. Correlations between neurophysiological and elastography parameters were weak to moderate (ρ ranging from -0.49 to 0.45). Inter-observer reliability of MEMSs scoring ranged from poor to moderate across the examined muscle groups, with Cohen's κ values ranging from -0.02 to 0.54.

Conclusions

RTE using MEMSs did not demonstrate sufficient validity or reproducibility for assessing muscle spasticity in MS, showing poor agreement with both clinical and neurophysiological measures.