Mean contact quotient using electroglottography in patients with multiple sclerosis

To compare the mean and standard deviation (SD) of the contact quotient (CQ) of the sustained vowels ([a] and [e]) in multiple sclerosis (MS) patients versus controls.

Cross-sectional study.

Thirty-nine subjects (24 patients and 15 controls) participated in this study. Laryngeal electroglottography was performed on all subjects while phonating the vowels [a] and [e] at a comfortable pitch and loudness. The fundamental frequency, mean CQ, SDs, and jitter were computed for both vocal tasks.

The mean age of the MS group was 36.25+10.61 years. All laryngeal examinations were normal and five patients with MS had dysphonia described as voice breaks and fatigue in connected speech. For both vowels [a] and [e], the mean closed quotients were comparable in groups, MS and control (43.90 vs 53 for [a] and 44.75 vs 43.63 for [e]) with no significant difference. When comparing five MS patients with dysphonia versus controls, for the vowel [a], the mean closed quotient was significantly lower in MS patients with dysphonia (P values of 0.043).

The mean closed quotient for sustained vowels [a] and [e] are comparable in MS patients and healthy controls except in patients with dysphonia.