Yield of Imaging to Evaluate Unilateral Vocal Fold Paralysis of Unknown Etiology.

Objectives/hypothesis: To identify the incidence and nature of positive findings on imaging studies ordered for evaluation of unilateral vocal fold paralysis (UVFP) of unknown etiology, to analyze these findings based on laterality, and to examine the use of the expanded-field computed tomography (CT) neck protocol in this evaluation.

Study Design: Retrospective review.

Methods: A total of 145 patients from 2000 to 2018 with UVFP of unknown etiology were studied. Data on imaging studies ordered, laterality of paralysis, and significant positive results were studied. An expanded-field CT neck protocol that included the entire course of the vagus and recurrent laryngeal nerves was instituted during the study period.

Results: A total of 20.7% of patients had an etiology for paralysis identified on imaging. Malignancies comprised the majority of findings overall (19/30), whether in the chest (12/18) or the neck (7/12). Etiology was more often found in the chest for left-sided paralysis (15/21) and in the neck for right-sided paralysis (6/9). In 26 patients who underwent both expanded-field CT neck and CT chest, no findings related to the UVFP were seen on CT chest that were not captured by expanded-field CT neck.

Conclusions: This is one of the largest retrospective studies examining the incidence of positive findings on imaging studies for evaluation of UVFP of unknown etiology. Imaging in one of five patients with UVFP of unknown etiology will reveal a causative lesion, most often malignant. Left-sided paralysis tends to localize to the chest, and right-sided paralysis to the neck. Expanded-field CT neck may allow practitioners to forego dedicated CT chest in evaluation of UVFP.

Level Of Evidence: 4 Laryngoscope, 131:1840-1844, 2021.