Assessment of Voice Changes in Myasthenia Gravis Patients

Objective: This study aims to examine the changes between the measurements done in the morning and evening in some acoustic analyses of patients having myasthenia gravis (MG). Materials and Methods: Twenty-four MG patients diagnosed with Phase-2A (Mildly Generalized MG) according to the classification of Osserman and Genkins by a neurology specialist were involved. Videolaryngostroboscopic examinations and acoustic analyses of these patients were performed in the Ear, Nose, and Throat (ENT) clinic. Perceptual voice assessments were performed using the GRBASI scale, Fo, Shimmer, Jitter, NHR (Noise to harmonic ratio), MPT (Maximum Phonation Time), and s/z rates were calculated. Results: When the morning and evening vocal measurements of patients were compared according to the GRBASI scale, a significant difference was found between B and A and S values, while no statistically significant difference was found between G, R, and I value. Statistically significant differences were found between cases’ Fo, Shimmer, NHR, s/z Ratio, and VHI (voice handicap index) measurements made in the morning and the evening. But no difference was found between the Jitter measurements. A statistically significant difference was found between the morning and evening values of men’s Fo and MPT measurements. Again, a statistically significant difference was found between the morning and evening values of women’s Fo and MPT measurements. Conclusion: For Myasthenia Gravis patients, the decrease in muscle power within the day and the tiredness in larynx muscles are an expected process, and it is objectively presented in this study. In addition, further studies are needed to show that possible communication problems can be prevented with sound therapies by evaluating the morning and evening acoustic analyses of MG patients.