Search

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.

The expiratory disproportion index (EDI) is the ratio of forced expiratory volume in 1 second divided by peak expiratory flow rate multiplied by 100. An elevated EDI (50) can help differentiate upper airway stenosis from other dyspnea etiologies, but this has not been verified when considering body habitus. We hypothesize that the predictive value of elevated EDI in diagnosing airway stenosis will be lower in obese patients as compared to nonobese patients.Retrospective cohort study.Patients18 years old with recorded pulmonary function test values, body mass index (BMI), and airway imaging were reviewed retrospectively from January 2011 to October 2018. EDI was recorded for four cohorts: nonobese and nonstenotic, obese and nonstenotic, nonobese and stenotic, and obese and stenotic, to determine the mean EDI and the sensitivity and specificity of an elevated EDI.Mean EDI values were 66.53 ± 17.66 and 49.55 ± 2.04 in the nonobese stenotic and nonstenotic groups, respectively (P .01). They were 58.00 ± 10.79 and 45.02 ± 1.42 in the obese stenotic and nonstenotic groups, respectively (P .01). At a threshold of50, EDI had a sensitivity of 83.3% and specificity of 56.2% in differentiating between stenotic and nonstenotic cases in the nonobese cohort and 50.0% and 71.9% in the obese cohort.As previously established, mean EDI values were significantly different in stenotic and nonstenotic patients in both BMI cohorts. However, at the established threshold of50, EDI was not as sensitive at identifying stenotic cases in obese patients as in nonobese patients. This suggests that the EDI remains useful in obese patients when elevated but should not be relied upon to rule out stenosis.4 Laryngoscope, 131:606-609, 2021.