Radiology findings in adult patients with vocal fold paralysis

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.

Does the Severity of Vocal Fold Paresis on Laryngeal Electromyography Correlate With Radiographic Findings on Cross Sectional Imaging?

OBJECTIVES

Unilateral vocal fold paresis or paralysis (UVFP) is a condition for which radiographic evaluation and laryngeal electromyography (LEMG) are valuable to evaluate severity of injury and direct treatment plans. Despite extensive research involving findings suggestive of UVFP with radiographic imaging, no study has attempted to determine which findings suggestive of UVFP on imaging are clinically significant and suggest a need for intervention. The purpose of this study was to evaluate whether the severity of vocal fold paresis/paralysis affects the likelihood of encountering radiographic findings suggestive of UVFP. We also aimed to determine which findings suggestive of UVFP on imaging were clinically significant and were associated with surgical intervention.

MATERIALS AND METHODS

A retrospective chart review was conducted of patients who had been diagnosed with unilateral vocal fold paresis or paralysis and had been evaluated by CT scan and/or magnetic resonance imaging and laryngeal electromyography (EMG) between the dates of January 1, 2017 and January 9, 2018. Fisher's exact testing with Monte Carlo Simulation was utilized to determine statistical significance of identified relationships. Univariate analysis was conducted to assess for individual relationships between imaging results and the potential predictor variables. Chi square analysis was conducted with the various categorical variables to assess for any potential relationships to imaging results. Statistical significance was determined utilizing chi square analysis.

RESULTS

After data collection, 130 patients were included in the study population. Of the 112 patients with documented MRI results, 17% had a reported imaging abnormality suggestive of true vocal fold paresis or paralysis (VFP). Of the 71 patients with documented CT Neck results, 15.4% had an abnormality potentially concerning for true VFP. The average decrease in recruitment of the right and left SLN was 23.8% and 26.1%, respectively. The average decrease in recruitment of the right and left RLN was 37.3% and 57.78%, respectively. Seventy four percent of patients who exhibited abnormal MRI were found to have isolated SLN weakness, and 21% of patients were found to have a combined SLN and ipsilateral RLN weakness. In patients with abnormal CT scans 45% were found to have isolated SLN weakness, and 35% were found to have a combined SLN and RLN weakness. MRI imaging again failed to display any significant degree of paresis. However, abnormal CT results displayed severe CN X paresis in 36.84% vs 1.96% in normal scans. The chance of an abnormal MRI and CT result was 2.78 and 5.55 times greater, respectively, for each increase in the degree of severity of CN X paresis. When looking at the ability of imaging to predict the chance of a patient undergoing surgery, 34.8% of patients with an abnormal MRI underwent surgery compared to just 14.61% of those with normal scans. For CT scans, 35% of patients with an abnormal scan underwent surgery, compared with only 15.69% with normal imaging. When pooled, over 33% of patients with any abnormal imaging underwent a laryngeal procedure compared to 13% of patients with normal imaging.

CONCLUSIONS

There is a relationship between severity of vocal fold paresis found on laryngeal EMG and likelihood of detection on imaging. While CT was more likely to find characteristics of UVFP than MRI, patients who had an abnormal finding on either modality were more likely to undergo surgical intervention. These findings highlight the importance of early referral of patients with abnormal laryngeal imaging to an otolaryngologist for evaluation and possible intervention.

Revisiting CT Signs of Unilateral Vocal Fold Paralysis: A Single, Blinded Study

BACKGROUND AND PURPOSE

Several CT findings are thought to be indicative of vocal cord paralysis; however, these signs have never been validated in a blinded fashion. This study attempts to compare and validate these signs and determine their accuracy in predicting vocal cord paralysis.

MATERIALS AND METHODS

A retrospective chart review was performed, and CT scans from patients with known unilateral vocal cord paralysis and known normal vocal cord movement were reviewed by 3 radiologists who were blinded to the status of the patients' laryngeal function. The scans were reviewed and scored for 8 accepted signs of vocal cord paralysis as well as for predicting a final diagnostic conclusion. Statistical analysis using odds ratios for signs and the Fleiss κ for criterion agreement among the radiologists was performed for diagnostic accuracy.

RESULTS

The presence of medial displacement of the posterior ipsilateral vocal fold margin and ipsilateral laryngeal ventricular dilation yielded the greatest positive predictive value. Other signs demonstrated high specificity, but interrater discrepancy was greater than expected and diminished the reliability of these signs in predicting vocal cord paralysis. Overall, sensitivity and negative predictive values were low.

CONCLUSIONS

Predicting vocal cord paralysis on the basis of CT findings is not as accurate or straightforward in prospectively predicting vocal cord paralysis as implied in prior studies.

Guidelines for the Management of Unilateral Vocal Fold Paralysis From the Korean Society of Laryngology, Phoniatrics and Logopedics

The Korean Society of Laryngology, Phoniatrics and Logopedics appointed a task force to establish clinical practice guidelines for the management of unilateral vocal fold paralysis (UVFP). These guidelines cover a comprehensive range of management-related factors, including the diagnosis and treatment of UVFP, and provide in-depth information based on current, up-to-date knowledge. Detailed evidence profiles are provided for each recommendation. The CORE databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers, using a predefined search strategy. When insufficient evidence existed, expert opinions and Delphi questionnaires were used to fill the evidence gap. The committee developed 16 evidence-based recommendations in six categories: initial evaluation (R1–4), spontaneous recovery (R5), medical treatment (R6), surgical treatment (R7–14), voice therapy (R15), and aspiration prevention (R16). The goal of these guidelines is to assist general otolaryngologists and speech-language pathologists who are primarily responsible for treating patients with UVFP. These guidelines are also intended to facilitate understanding of the condition among other health-care providers, including primary care physicians, nurses, and policy-makers.

Comparison of arytenoid vertical height discrepancy in normal versus patients with vocal cord palsy

OBJECTIVE

Cadaveric experiments and more recently clinical data have demonstrated that patients with vertical height discrepancy between their arytenoids experience poorer voice outcomes in patients with unilateral vocal cord palsy (UVP) after medialisation laryngoplasty. However, the presence or severity of height discrepancy in normal patients without UVP has not yet been clearly defined.

STUDY DESIGN

Case-control study.

SETTING

Tertiary Australian hospitals.

SUBJECTS AND METHODS

A retrospective review was performed on patients who underwent high computed tomography imaging of the neck. Scans were assessed for discrepancy in arytenoid vertical height discrepancy and compared to a cohort with known UVP.

RESULTS

44 normal patients (50% female, mean age 57.6 ± 14.8 years) were compared to 23 patients with UVP (43.4% female, mean age 52.3 ± 14.9 years.) Normal patients were found to have a smaller height discrepancy compared to UVP patients (student's t-test,2.00 mm ± 0.00 vs 2.39 mm ± 0.72, p < .001.) CONCLUSION: This study suggests that discrepancy is pathologic, and it is plausible that this results in acoustic consequences.

Imaging Modalities in the Etiologic Evaluation of Unilateral Vocal Fold Paralysis

OBJECTIVE

This study aimed to investigate the roles of computed tomography (CT) and neck ultrasonography (US) in evaluating unilateral vocal fold paralysis (UVFP) of unknown etiology and to compare our results with those of other studies to assess the differences in etiology of UVFP.

METHODS

We investigated the medical records of 202 eligible patients with UVFP. In total, 168 underwent chest CT, 118 underwent neck CT, and 108 underwent head CT. One hundred and three patients were also evaluated with high-resolution neck US. The etiologic causes of UVFP were also determined.

RESULTS

Of the 202 eligible patients, the occult cause of the UVFP was determined in 96 patients (47.5%). Idiopathic causes were the most common etiologies (n = 106). In occult causes group, chest lesions were the most common diseases causing paralysis (52 cases) and included lung cancer (n = 28) and mediastinal malignancy (n = 8). More than half of the neck lesions were of thyroid origin. Of the 18 thyroid lesions, 12 were thyroid malignancies. Chest CT had an intermediate yield of 30.9% (52 of 168). Neck US had a diagnostic yield close to that of neck CT (26.2%).

CONCLUSION

UVFP may result mainly from idiopathic, lung cancer, mediastinal, and thyroid malignancies. The initial use of neck US as an alternative to CT may be advocated for the determination of diseases resulting in UVFP.

Causes and imaging manifestations of paralysis of the recurrent laryngeal nerve

The vocal cords play a key role in the functions of the larynx. Their motor innervation depends on the recurrent laryngeal nerve (a branch of the tenth cranial nerve), which follows a long trajectory comprising intracranial, cervical, and mediastinal segments. Vocal cord paralysis usually manifests as dysphonia, the main symptom calling for CT study, the first-line imaging test to investigate the cause of the lesion. Patients are asymptomatic in a third of cases, so the incidental detection of signs of vocal cord paralysis in a CT study done for other reasons should prompt a search for a potentially severe occult lesion. This article aims to familiarize readers with the anatomy of the motor innervation of the glottis, the radiological presentation and most common causes of vocal cord paralysis, and conditions that can simulate vocal cord paralysis.

Vocal cord paralysis: anatomy, imaging and pathology

Vocal cord paralysis (VCP) can be caused by any process that interferes with the normal function of the vagal nerves or recurrent laryngeal nerves. It may be a first sign of extensive and severe pathology. Radiologists must therefore be able to recognise the imaging findings of VCP and know the course of the vagal and recurrent laryngeal nerves. This review focuses on the anatomy and imaging evaluation of these nerves and thereby the possible sites for pathology causing VCP. The imaging characteristics and imaging mimics of VCP are discussed and cases from daily practice illustrating causes of VCP are presented.

• Vocal cord paralysis may be the first presentation of severe pathology.

• Radiologists must be aware of imaging characteristics and mimics of vocal cord paralysis.

• Lesions along the vagal nerves and recurrent laryngeal nerves can cause vocal cord paralysis.

Losing your voice: etiologies and imaging features of vocal fold paralysis

Neurogenic compromise of vocal fold function exists along a continuum encompassing vocal cord hypomobility (paresis) to vocal fold immobility (paralysis) with varying degrees and patterns of reinnervation. Vocal fold paralysis (VFP) may result from injury to the vagus or the recurrent laryngeal nerves anywhere along their course from the brainstem to the larynx. In this article, we review the anatomy of the vagus and recurrent laryngeal nerves and examine the various etiologies of VFP. Selected cases are presented with discussion of key imaging features of VFP including radiologic findings specific to central vagal neuropathy and peripheral recurrent nerve paralysis.

Recommendations on follow-up strategies for idiopathic vocal fold paralysis: evidence-based review

Introduction:

Vocal fold paralysis can be an early warning sign of serious extra-laryngeal pathology. Even if imaging investigations show no pathology, there is always concern about the emergence of new pathology in the future. There is currently no consensus on the best follow-up protocol for vocal fold paralysis patients with no abnormalities on investigation.

Methods:

Systematic review, using an Ovid and Medline database search of papers written in the English language and published in the last 20 years.

Results:

Eight relevant studies were identified. Not all of them were directly comparable. A narrative review of the studies is presented and conclusions are drawn.

Conclusion:

Current diagnostic modalities are sufficiently reliable and sensitive to diagnose any significant existing extra-laryngeal pathology. Thus, once initial investigation (including computed tomography) has concluded, no further follow up is necessary.

Clinical Practice Guideline: Hoarseness (Dysphonia)

Objective:

This guideline provides evidence-based recommendations on managing hoarseness (dysphonia), defined as a disorder characterized by altered vocal quality, pitch, loudness, or vocal effort that impairs communication or reduces voice-related quality of life (QOL). Hoarseness affects nearly one-third of the population at some point in their lives. This guideline applies to all age groups evaluated in a setting where hoarseness would be identified or managed. It is intended for all clinicians who are likely to diagnose and manage patients with hoarseness.

Purpose:

The primary purpose of this guideline is to improve diagnostic accuracy for hoarseness (dysphonia), reduce inappropriate antibiotic use, reduce inappropriate steroid use, reduce inappropriate use of anti-reflux medications, reduce inappropriate use of radiographic imaging, and promote appropriate use of laryngoscopy, voice therapy, and surgery. In creating this guideline the American Academy of Otolaryngology—Head and Neck Surgery Foundation selected a panel representing the fields of neurology, speech-language pathology, professional voice teaching, family medicine, pulmonology, geriatric medicine, nursing, internal medicine, otolaryngology–head and neck surgery, pediatrics, and consumers.

Results

The panel made strong recommendations that 1) the clinician should not routinely prescribe antibiotics to treat hoarseness and 2) the clinician should advocate voice therapy for patients diagnosed with hoarseness that reduces voice-related QOL. The panel made recommendations that 1) the clinician should diagnose hoarseness (dysphonia) in a patient with altered voice quality, pitch, loudness, or vocal effort that impairs communication or reduces voice-related QOL; 2) the clinician should assess the patient with hoarseness by history and/or physical examination for factors that modify management, such as one or more of the following: recent surgical procedures involving the neck or affecting the recurrent laryngeal nerve, recent endotracheal intubation, radiation treatment to the neck, a history of tobacco abuse, and occupation as a singer or vocal performer; 3) the clinician should visualize the patient's larynx, or refer the patient to a clinician who can visualize the larynx, when hoarseness fails to resolve by a maximum of three months after onset, or irrespective of duration if a serious underlying cause is suspected; 4) the clinician should not obtain computed tomography or magnetic resonance imaging of the patient with a primary complaint of hoarseness prior to visualizing the larynx; 5) the clinician should not prescribe anti-reflux medications for patients with hoarseness without signs or symptoms of gastroesophageal reflux disease; 6) the clinician should not routinely prescribe oral corticosteroids to treat hoarseness; 7) the clinician should visualize the larynx before prescribing voice therapy and document/communicate the results to the speech-language pathologist; and 8) the clinician should prescribe, or refer the patient to a clinician who can prescribe, botulinum toxin injections for the treatment of hoarseness caused by adductor spasmodic dysphonia. The panel offered as options that 1) the clinician may perform laryngoscopy at any time in a patient with hoarseness, or may refer the patient to a clinician who can visualize the larynx; 2) the clinician may prescribe anti-reflux medication for patients with hoarseness and signs of chronic laryngitis; and 3) the clinician may educate/counsel patients with hoarseness about control/preventive measures.

Disclaimer:

This clinical practice guideline is not intended as a sole source of guidance in managing hoarseness (dysphonia). Rather, it is designed to assist clinicians by providing an evidence-based framework for decision-making strategies. The guideline is not intended to replace clinical judgment or establish a protocol for all individuals with this condition, and may not provide the only appropriate approach to diagnosing and managing this problem.

Prospective study to assess vocal cord palsy investigations1

Objectives

To assess the investigation and clinical outcome of patients presenting with unexplained vocal cord palsy (VCP).

Study Design and Methods

A prospective cohort study designed to evaluate 86 patients with unexplained VCP presenting to our tertiary referral center.

Results

Twenty-four (36%) patients had positive findings on CT scanning. Twenty-one (24%) cases showed mediastinal adenopathy ± pulmonary mass. The other three cases were a thoracic aneurysm, prostatic metastasis below the skull base, and a post-cricoid tumor. Follow-up period was 18 to 66 months. Fifteen (24%) of the 62 patients with negative radiology recovered full vocal cord movement.

Conclusion

CT neck ± chest plays an important role in the evaluation of VCP patients. The majority of pertinent radiologic findings involve malignant neoplasm.