Idiopathic Unilateral Vocal Fold Paralysis in Older Patients: Characteristics in the Disease Course and Implication of Computed Tomography for Evaluation of Etiology

Imaging Modalities for Identifying Causes of Vocal Fold Paralysis: A Systematic Review and Meta-Analysis

BACKGROUND

Vocal fold paralysis (VFP), involving one or both vocal folds, often indicates underlying pathologies. Identifying VFP causes is vital for excluding malignancies and focusing on treating the cause. While various imaging methods are used to investigate VFP causes, their detection abilities remain unclear. This study aims to assess the detection prevalence of different imaging techniques in determining the causes of VFP.

METHODS

In September 2023 a comprehensive search was conducted per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines across multiple databases, including Web of Science, PubMed, Scopus, Cochrane CENTRAL, and EMBASE. Following the search, the retrieved studies were screened based on the predefined eligibility criteria. Data extraction from the included studies was carried out independently by two authors. Outcomes were analyzed using pooled proportions and 95% confidence intervals.

RESULTS

Our meta-analysis encompassed 14 studies with 1492 VFP patients included. Malignant causes for VFP identification were most prevalent in F-fluorodeoxyglucose Positron Emission Tomography (PET)/Computed Tomography (CT) (41.5%) followed by Magnetic resonance imaging (MRI) (40%), with CT being the lowest (17.1%). Conversely, benign causes had the highest prevalence in F-fluorodeoxyglucose PET/CT (10.8%), followed by MRI (6.7%) and CT (4%). In the VFP cause identification, MRI had the highest detection prevalence (58.1%), followed by CT (30.1%), and Ultra Sound (US) had the lowest (26.8%). In chest lesion detection, CT had the highest prevalence (17.6%), followed by Chest X-ray (CXR) (6.5%). Head lesions were detected with CT at a prevalence of 15%, while neck lesion detection showed CT prevalence at 38.9% and US at 20.6%.

CONCLUSION

Our study revealed varying prevalence rates for the identification of malignant and benign causes across different imaging modalities. MRI demonstrated the highest overall detection prevalence for VFP causes, while CT was most commonly used and had the highest prevalence for specific lesions detection in various regions. These findings provide valuable insights into the diagnostic utility of different imaging techniques in the evaluation of VFP.

Computed Tomography Measurements in Assessment of Idiopathic Vocal Fold Paralysis

OBJECTIVE

Our study aimed to both identify the incidence and clinical presentation of patients presenting with idiopathic vocal fold paralysis (IVFP). Secondarily we aimed to assess the radiographic findings of computed tomography (CT) studies along the course of the vagus and recurrent laryngeal nerves (RLN), specifically measuring for potential areas of compression at the skull base and mediastinum. We hypothesized that a proportion of patients diagnosed with IVFP would have significant differences in measurements when compared to age-gender matched controls on CT imaging.

STUDY DESIGN

Institutional review board approved retrospective cohort study METHODS: We assessed patients presenting to a tertiary voice care center between 2003 and 2019 with diagnosis of vocal fold paralysis. Data collected includes demographics, clinical exam findings, and CT measurements including dimensions at bilateral jugular foramen, aortopulmonary (AP) window and surrounding vascular structures. Statistical analysis was then performed using Pearson χ², and Mann Whitney U tests to determine differences variables of interest.

RESULTS

A total of 606 patients were reviewed. Of these patients 60 (9.9%) patients were determined to have IVFP. Left-sided VFP was seen more commonly in 78.3% (N = 47) of idiopathic patients. Our IVFP group had an overall higher incidence of cardiovascular disease [OR = 3.378, 95%CI 1.907-5.941, P < 0.001] compared to those with identified causes for paralysis. Specifically, IVFP patients showed a higher incidence of combined cardiovascular co-morbidities (P < 0.001), mitral valve stenosis (P = 0.007), pulmonary hypertension (P < 0.0001) and congestive heart failure (P < 0.001). When evaluating CT imaging, the AP window was mentioned in only 2 (3.3%) of our idiopathic patients CT reports. The IVFP cohort had a lower median AP window volume (P = 0.020) when compared to age-gender matched controls. This significantly smaller AP window volume was also seen when only left sided IVFP compared to both right-sided paralysis (P < 0.001) and age matched control patients (P < 0.001).

CONCLUSION

The significance of cardiovascular comorbidities combined with findings of statistically narrowed AP window may help provide an explanation of a subset of patients diagnosed with IVFP.

Volumetric measures of the paralyzed vocal fold using computerized tomography; its clinical implication

OBJECTIVE

To report the volumetric measures of the paralyzed vocal fold in patients undergoing injection laryngoplasty.

MATERIAL AND METHOD

All the medical records of patients with unilateral vocal fold paralysis who had high resolution computerized tomography scan of the neck and chest prior to injection laryngoplasty between October 2015 and May 2018 were included. Volumetric evaluation of the vocal folds was performed by measuring the vocal fold height using coronal images and the vocal fold length and width using axial images.

RESULTS

A total of 21 patients divided into 13 males and 8 females were identified. The mean age was 56.66 ± 20.94 years. The mean volume of the paralyzed vocal fold was significantly smaller than that of the non-paralyzed vocal fold (p < .05). Similarly, the mean length and height of the paralyzed vocal folds were smaller than those of the non-paralyzed vocal folds (p < .05).

CONCLUSION

Volumetric measurements of the paralyzed vocal fold in comparison to the normal vocal fold in a group of 21 patients with unilateral vocal fold paralysis shows the presence of significant difference between the normal and affected site, and the presence of large inter-subject variation. Information on the volume difference between the two vocal folds may be used to better estimate the amount that needs to be injected in medialization procedures.