Correlation of electroglottograph with vocal cord pathology
Keywords:Electroglottograph, Rigid laryngoscopy, Jitter, Shimmer, Contact index, Opening rate, Closing rate, Contact quotient perturbation, Contact index perturbation
Background: Vocal cord disorders are very commonly encountered in ENT Outpatient. Electroglottogram is a non-invasive method for the examination of the vocal fold vibrations. It exerts no influence at all on articulation and production of sound and is cost effective. The aim of the present study was to validate the clinical correlation of electroglottogram in patients presenting with hoarseness of voice.
Methods: 30 patients with history of hoarseness of voice and 30 normals were selected from ENT outpatient and inpatient department over a period of 2 years. All subjects underwent detailed ENT history taking, clinical examination, rigid laryngoscopy and electroglottography and results were documented.
Results: Electroglottography waveforms of various voice disorders like vocal cord nodule, polyp, papilloma and haemangioma showed specific changes like double peak or notch in closing phase of waveform in case of mass lesion over the vocal cords and fuzzy waveform with prolonged closing time in case of vocal cord palsy. Significant difference was noted in certain electroglottographic parameters for phonated vowels /a/, /i/ and /u/ for certain vocal cord disorders.
Conclusions: Electroglottograph helps in diagnosing the pathology related to vocal cords, whether it is mass lesion over the vocal cords or vocal cord palsy but to differentiate in between mass lesions, clinical examination has to be done to confirm the diagnosis.
Hanson DG, Gerratt BR, Ward HP. Glottographic measurement of vocal dysfunction. A preliminary report. Ann Otorhinolaryngol. 1983;92(5):413-9.
Baken RJ. Electroglottography. J Voice. 1992;6(2):98-110.
Fabre P. Sphygmograpic par simple contact d’ electrodes cutane’es introdusiant dans 1 artere’ de faibles ‘Courants de haute fre’quence detecteurs de ses variations volume’triques’. Comptes Rendus Soc Biol. 1940;133:639-41.
Colton RH, Conture EG. Problems and pitfalls of Electroglottography. J Voice. 1990;4(1):10-24.
Abberton E, Howard D, Fourcin A. Laryngographic assessment of normal voice a tutorial. Clin Linguist Phon. 1989;3:281-96.
Wei C, Chen F, Wang W. Analysis of the EGG waveform of vocal polyps. Lin Chuang Er Bi Yan Hou Ke Za Zhi. 1997;11(7):299-301.
Zag’olski O, Carlson E. Electroglottgraphic measurement of glottal function in vocal cord paralysis in women. Clinl Otolaryngol Allied Sci. 2002;27(4):246-53.