Publications

Background: Dysphagia occurring in the oral and pharyngeal phases of swallowing in MS patients may be caused by changes in muscles’ viscoelasticity. The aim of this study was to compare the muscles’ (sternocloideomastoideus and masseter) viscoelasticity properties by myotonometer between MS patients and healthy individuals.

Methods: This study design was a cross-sectional, non-interventional study. Ten healthy individuals were allocated to the control group, eleven MS patients without swallowing problems were allocated to the without swallowing group, ten MS patients with swallowing problems were allocated to the swallowing group. Disability was evaluated using the Expanded Disability Status Scale (EDSS), swallowing problem was assessed with Dysphagia in Multiple Sclerosis (DYMUS) scale, and to measure the viscoelastic parameters (tone, stiffness, elasticity) of sternocloideomastoideus (SCM) and masseter muscles bilaterally, MyotonPro® was used. The comparison between the groups was performed using the Kruskal-Wallis H test.

Results: It was observed that there was no difference in terms of viscoelastic properties of the masseter muscle in groups (p > 0.05). There was no difference between the groups in terms of the elasticity of the SCM muscle (p > 0.05). However, the tonus and stiffness of the SCM on the left side of the MS patients were higher than in other groups (p = 0.050, p = 0.005).

Conclusion: The increment level of tone and stiffness of SCM muscle is related to swallowing problems in patients with MS. Due to swallowing problems in MS, the orofacial and neck region’s muscles’ viscoelastic properties may change in time and may be affected by phases of swallowing problems.

Keywords: deglutition disorders, multiple sclerosis, muscle tonus, masseter muscle, myotonometer

The study was designed to compare the muscles’ (SCM and Masseter) viscoelasticity properties by myotonometer between MS patients and healthy individuals. The tone and stiffness of the left side SCM muscle were higher in the SG group, according to the study. MS patients with swallowing problems state that the most common symptom was difficulty in swallowing solid foods. Although MS disease does not affect the viscoelastic properties of the masseter muscle bilaterally, unilateral SCM muscle tone and stiffness might increase in MS patients with swallowing problems. MS patients with swallowing problems could increase the stiffness of the unilateral SCM muscle with the swallowing strategies (compensation) they have developed. Clinicians may pay attention to asymmetric postural deviations, especially in the cervical region, when evaluating swallowing. It could be useful to investigate the effects of treatments on muscles’ viscoelastic properties in MS patients with swallowing problems in further studies.