The existence of phonatory instability in multiple sclerosis: an acoustic and electroglottographic study.

Dysarthria and phonatory symptomatology are often reported by patients suffering from multiple sclerosis (MS), but have been poorly investigated, although related to life quality. The objective of the study was to investigate the phonatory function in MS patients using objective measures. The speech of 64 MS patients and 64 pair-matched controls was recorded and analyzed using electroglottography, a physiological method that measures the electrical conductance during the opening and closing phases of the vibrating vocal folds.