Muscle elastography: a new imaging technique for multiple sclerosis spasticity measurement

Multiple sclerosis (MS) spasticity is currently evaluated on the basis of neurological examinations such as Ashworth Scale (AS) and 0-10 NRS. Severity of spasticity is difficult to quantify. We investigated the use of real time elastography (RTHE) ultrasounds for evaluating objectively the muscle fibers status in MS spasticity patients and their changes after a new antispasticity treatment. Two studies were performed. In study A, 110 MS patients underwent a neurological evaluation based on the AS and RTHE. The RTHE images were scored with the new 1-5 muscle fibers rigidity imaging scale, here called MEMSs (Muscle Elastography Multiple Sclerosis Score). The correlation between AS and MEMSs was found to be statistically significant. In study B, 55 MS patients treated with THC:CBD oromucosal spray for their resistant spasticity were followed prospectively. MS spasticity was evaluated by the 0-10 NRS scale at baseline and after 4 weeks of treatment. MEMSs' figures were obtained at both timepoints. Responders to THC:CBD oromucosal spray (pre-defined as an improvement ≥20% in their 0-10 NRS spasticity score vs. baseline) were 65% of sample. These patients had a mean 0-10 NRS reduction of 1.87 and a MEMSs reduction of 1.97 (P values <0.0001). The remaining 35% of patients, classified as clinically non-responders, showed still a significant mean reduction in MEMSs (0.8, P = 0.002). Our overall results showed that RTHE, operativized throughout MEMSs, could be an objective gold standard to evaluate MS muscle spasticity as well as the effectiveness of antispasticity therapy.