Kostas Konstantopoulos
European University Cyprus, Cyprus
Title: The use of electroglottography in the assessment of voice in neurological diseases
Biography
Biography: Kostas Konstantopoulos
Abstract
Statement of the Problem: In the last eight years, there are an increased number of studies that gave emphasis on the quantification of voice symptomatology in different neurological diseases. The present speech aims to discuss the findings of voice production in these studies in neurological diseases such as myasthenia gravis (MG), multiple sclerosis (MS), essential voice tremor (ET), and Parkinson’s disease (PD).
Methodology & Theoretical Orientation: All studies used a pair-matched methodology. A combination of tasks (sustained phonation and reading of a standard text passage) was used to measure voice. Electroglottography (EGG) as an indirect and non-invasive imaging technique, measures changes in electrical resistance between electrodes placed over the thyroid cartilage. EGG waveforms measure the duration of the relative vocal fold contact patterns within the glottal cycle and they are produced when the contact of the vocal folds increases as electrical impedance decreases. In ENT, EGG has been used to describe irregularities in vocal fold vibration in patients diagnosed with vocal fold nodules, vocal fold cysts and glottal cancers. In the present study, EGG numerical data were extracted and measures of central tendency were shown as a distribution of frequencies. The recordings were obtained using a laptop Sony Vaio that was connected to an electroglottograph processor (PCLX) (Laryngograph Ltd, London, UK).
Findings: The mean fundamental frequency of the vibrating vocal folds, the standard deviation of the vibrating vocal folds, the jitter and the fundamental frequency range were found to differentiate patient groups from the control groups.
Conclusion & Significance: EGG is a sensitive measure of pathology in the dysarthrophonia of different neurological diseases. Further research may study the quantification of voice early in the disease process to help in the differential neurological diagnosis (for example in diseases such as myasthenia gravis vs. ALS).