False Vocal Fold Characteristics in Presbylarynges and Recurrent Laryngeal Neuropathy

Objective: Conflicting data exist regarding false vocal fold (FVF) anatomy; it is unclear if this structure is an extension of the thyroarytenoid muscle or an independent muscle system. This confusion is amplified by diverse clinical findings in the setting of unilateral recurrent laryngeal neuropathy and presbylarynges. We sought to characterize FVF behavior in these contexts. Methods: Laryngoscopic/stroboscopic examinations from 11 patients with unilateral recurrent laryngeal nerve paresis and 12 patients with presbylarynges were reviewed by 4 laryngologists, blinded to the goal of the study but informed of diagnosis. Variables related to FVF structure and function at rest and during phonation were rated. Results: In recurrent laryngeal neuropathy, no significant association between atrophic/paretic vocal fold (VF) and FVF size was observed at rest (P =.69). During phonation, FVF compression was noted bilaterally; contralateral FVF hypertrophy was more common (P =.002). In presbylarynges, neither FVF size at rest (P =.86) nor compression during phonation (P =.37) was associated with the more atrophic VF; FVF compression/hypertrophy was common. Conclusions: Consistent with clinical dogma, FVF compression was more common contralateral to VF neuropathy. This finding, however, was inconsistent and may suggest individual variability in FVF innervation and/or morphology. Intra- and interrater reliability of these clinical findings was poor.