Positive Predictive Value of Endoscopic Findings to Diagnose Vocal Fold Paresis

Laryngoscopy corresponding with laryngeal electromyography (LEMG) is essential in diagnosing vocal fold paresis. However, baseline asymmetry or other diseases oftentimes confound the exam, making diagnosis difficult. There is currently no agreed upon endoscopic criteria proven to reliably correlate with LEMG findings. We define a set of endoscopic findings termed "paresis triad" that, when present together, reliably correlate with LEMG. The paresis triad consists of (1) hypocontraction of the weak side of the larynx with increased ventricular show, (2) hypercontraction of the intact side with bulging of the false fold covering the ventricle, and (3) tilting of the interarytenoid cleft to the weak side.

We performed a retrospective review of patients with laryngeal asymmetry on laryngoscopy. Patients were divided into two groups: those with consistent paresis triad findings across all pitches and intensities, and those without. All patients underwent LEMG by a neurolaryngologist blinded to the laryngoscopic findings. The endoscopies were then rereviewed in a blinded manner by a second laryngologist to assess inter- and intrarater reliability for identification of the triad.

Twelve patients met inclusion criteria (age 50 +/-15, 7F:5M). Nine had the paresis triad. Three had an inconsistent triad. All patients with the paresis triad had LEMG findings consistent with neurologic injury on the suspected side. All patients with inconsistent triad findings had normal LEMG.

Our findings suggest the proposed laryngoscopic paresis triad may be useful objective criteria to diagnose paresis without the need for LEMG. Further prospective studies should examine a larger series of patients.

4 Laryngoscope, 133:1712-1716, 2023.