Phoniatric studies in myasthenia gravis patients

The authors have for the first time evaluated the basic parameters of the V oice using computed voice analysis in patients with myasthenia gravis (MG). The aim of the study was to introduce an objective method suitable for the assessment of dysphonic symptoms,which predominate in bulbar, oculobulbar and generalized MG. Voice profile studies included the evaluation of the si nging voice range,voice dynamics, maximum phonation time, and mean fundamen tal frequency and intensity during speech. The characteristic of the strobo scopic picture was also determined. Investigations were carried out before and after the intake of Mestinon, a reversible cholinesterase inhibitor, an d healthy subjects were used as a control group. In MG, the voice range and dynamics are badly impaired, maximum phonation time is shortened, the mean fundamental frequency during speech is increased, while the intensity is d ecreased. Mestinon resulted in an improvement in all these parameters, howe ver,they were still impaired in comparison to the control subjects. Most ch anges were found to be statistically significant. The authors emphasize the role of the otolaryngologist and objective phoniatric methods in the evalu ation of MG and other myasthenia-like neurological diseases. The use of the se methods for the assessment of phoniatric symptoms in neurological diseas es is highly recommended.