Vocal Fold Paresis: Incidence, and the Relationship between Voice Handicap Index and Laryngeal EMG Findings

Abstract

To determine whether there is a correlation between Voice Handicap Index 10 (VHI-10) and degree of vocal fold paresis as determined by laryngeal EMG. Secondary objective was to determine the incidence of vocal fold paresis in a tertiary laryngology practice. A retrospective chart review of all new voice patients seen by the senior author (RTS) from January 1, 2016 to December 31, 2017. Subjects completed VHI at their initial visit. Patients were examined with flexible and rigid laryngoscopy and videostroboscopy and referred for laryngeal electromyography (LEMG) if neuromuscular weakness was suspected. LEMG was used to identify the affected nerves and to quantify subjectively the degree of paresis. Patients who did not complete LEMG and or handicap index were excluded from the correlation analysis. The prevalence of vocal fold paresis was determined by reviewing the records of each subject. The number of patients diagnosed clinically with paresis or paralysis and referred for LEMG was documented. The subjects, who had paresis confirmed on LEMG (n = 210) were grouped according to the nerves involved and by the degree of paresis. The unilateral superior laryngeal nerve and ipsilateral recurrent laryngeal nerve paresis group (n = 29) had a reasonably even distribution of patients in each sub-group (n = 11; 12; 6) and was analyzed for correlation. There was a strong positive correlation between the degree of paresis and the VHI score (r = 0.59, P < 0.001). Other groups did not have an even distribution among sub-groups and could not be to be analyzed for correlation. The senior author examined 344 new voice patients during years of 2016 and 2017. Based on laryngoscopy, 335 patients were referred for LEMG (97.4%). Two hundred thirty-seven patients had LEMG performed, and 234 patients confirmed to have vocal fold paresis were confirmed (98.7%.). The incidence of vocal fold paresis in subjects who underwent LEMG or who had normal motion during laryngoscopy was 95.1% (234 out of 246). The incidence in the 98 subjects who did not complete the recommended LEMG is unknown. The unilateral superior laryngeal nerve with ipsilateral recurrent laryngeal nerve paresis was the only group that allowed for analysis whether patient's perception of their voice problem as measured VHI-10 correlated with increasing degree of vocal fold paresis. A strong significant positive correlation in this group was identified. Additional studies with a larger patient cohort are recommended.