The evaluation of unilateral vocal fold immobility: is chest X-ray enough?

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.

Diagnostic yield of computed tomography in the evaluation of unilateral vocal fold palsy

BACKGROUND

There is a paucity of Asian-based data regarding the diagnostic yield of computed tomography imaging in the initial assessment of idiopathic unilateral vocal fold palsy.

OBJECTIVES

To investigate the diagnostic yield of computed tomography in idiopathic unilateral vocal fold palsy cases in an Asian tertiary hospital, and to determine the causative pathologies and positive predictive factors.

METHOD

A retrospective chart review was conducted of patients (between 2010 and 2018) with a clinical diagnosis of idiopathic unilateral vocal fold palsy who underwent contrast-enhanced computed tomography of the neck and chest at Tan Tock Seng Hospital, Singapore.

RESULTS

The overall computed tomography diagnostic yield was 21 per cent, with malignancy accounting for 63.6 per cent of diagnoses. Degree of vocal fold weakness was the only significant predictor of positive computed tomography findings (11.5 per cent in vocal fold paresis vs 29.1 per cent in vocal fold paralysis, p = 0.025). None of the patients with negative computed tomography findings went on to develop disease after a mean follow up of 14.3 months.

CONCLUSION

Computed tomography is a useful initial investigation for idiopathic unilateral vocal fold palsy, particularly in cases with vocal fold paralysis.

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.

Medical and Surgical Advances in the Treatment of Unilateral Vocal Fold Paralysis

Purpose

In this chapter, unilateral vocal fold paralysis is described, and treatment options are discussed with emphasis on recent developments in treatment.

Conclusion

Unilateral vocal fold paralysis is a disorder commonly encountered by otolaryngologists and speech-language pathologists alike and is caused by dysfunction of one of the recurrent laryngeal nerves leading to dysphonia and dysphagia. The etiology of this disorder can include malignancy, iatrogenic injury, or traumatic injury or may be due to idiopathic causes, and evidence has suggested that the rates of different etiologies have changed over time. Treatment options include a variety of approaches and range from expectant management, voice therapy, as well as surgical and procedural approaches. Surgical approaches generally aim to augment the affected vocal fold to medialize its position, thereby reducing glottic insufficiency, and can include injection laryngoplasty and laryngeal framework surgery. Recurrent laryngeal nerve reinnervation is also an option for certain patients and can improve vocal fold bulk by restoring basal neurologic stimulation. Though it is a well-described phenomenon, with new developments in procedural interventions, unilateral vocal fold paralysis remains a dynamic entity in the field.

Guidelines for radiographic imaging of cranial neuropathies

Disruption of the complex pathways of the 12 cranial nerves can occur at any site along their course, and many, varied pathologic processes may initially manifest as dysfunction and neuropathy. Radiographic imaging (computed topography or magnetic resonance imaging) is frequently used to evaluate cranial neuropathies; however, indications for imaging and imaging method of choice vary considerably between the cranial nerves. The purpose of this review is to provide an analysis of the diagnostic yield and the most clinically appropriate means to evaluate cranial neuropathies using radiographic imaging. Using the PubMed MEDLINE NCBI database, a total of 49,079 articles' results were retrieved on September 20, 2014. Scholarly articles that discuss the etiology, incidence, and use of imaging in the context of evaluation and diagnostic yield of the 12 cranial nerves were evaluated for the purposes of this review. We combined primary research, guidelines, and best practice recommendations to create a practical framework for the radiographic evaluation of cranial neuropathies.

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.

Diagnostic Yield of Computed Tomography in the Evaluation of Idiopathic Vocal Fold Paresis

Objective

To determine the diagnostic yield of computed tomography (CT) in establishing an etiology in patients with idiopathic unilateral vocal fold paresis (IUVFP). To determine the proportion of CT scans yielding incidental findings requiring further patient management.

Study Design

Case series with chart review.

Setting

Tertiary laryngology practice.

Subjects

Laryngology clinic patients under the care of the 2 senior authors.

Methods

All clinic patients were identified who had a diagnosis of IUVFP and underwent CT of the skull base to the upper mediastinum from 2004 to 2014. Demographic, historical, examination, and investigation data were extracted. CT reports and endoscopic recordings were reviewed. Patients were excluded if there were insufficient clinical findings recorded or if there was a known neurologic disorder, complete vocal fold immobility, or bilateral involvement.

Results

A total of 174 patients with IUVFP who had also undergone contrast-enhanced CT were identified. Of the 174 patients, 5 had a cause for their paresis identified on CT. This equated to a diagnostic yield of 2.9% (95% confidence interval, 0.94% to 6.6%). Of the 174 patients, 48 had other incidental lesions identified that required further follow-up, investigation, or treatment. This equated to an incidental yield of 27.6% (95% confidence interval, 21.1% to 34.9%).

Conclusion

This is the second and largest study to evaluate the diagnostic yield of CT in the evaluation of IUVFP. It demonstrates a low diagnostic yield and a high incidental yield. These findings suggest that the routine use of CT in the evaluation of idiopathic vocal fold paresis should be given careful consideration and that a tailored approach to investigation with good otolaryngologic follow-up is warranted.

Routine Computed Tomography in the Evaluation of Vocal Fold Movement Impairment without an Apparent Cause

Objective

Routine computed tomography (CT) for vocal fold movement impairment (VFMI) without an apparent cause is common. However, given increased cancer risk associated with ionizing radiation exposure, our purpose is to evaluate the utility of routine scans for these patients.

Study Design

Retrospective case series.

Setting

Houston, Texas.

Subjects and Methods

A 5‐year review of patients with VFMI diagnosed at an academic institution was conducted. For patients without an apparent cause (eg, recent head, neck, or cardiothoracic surgery or known malignancy), CT head/neck and chest was performed to evaluate the recurrent laryngeal nerve course. Data included demographics, symptoms, radiography, and interventions. Statistical analyses were performed via χ2 analysis.

Results

Of 406 patients with VFMI, 47 (11%) patients had no apparent cause clinically. Routine CT revealed abnormalities in 10 (21%) patients, of which only 3 (6%) could account for VFMI: benign thyroid adenoma (1), papillary thyroid cancer (1), and an esophageal mass (1). The most common lesion detected involved the thyroid. Demographic data and symptom type were not significantly associated with detection of a VFMI‐attributable lesion on CT. Overall, routine CT did not identify a focal etiology in 94% patients with VFMI without an apparent cause.

Conclusion

Routine pan‐CT evaluation failed to reveal an etiology in 94% of patients with VFMI without an apparent cause. Patients may be subjected to health risks associated with radiation exposure without significant diagnostic benefit. Further studies should consider more judicious use of CT in the context of risk factors and safer imaging modalities as the initial diagnostic step.

CT evaluation of vocal cord paralysis due to thoracic diseases: a 10-year retrospective study

PURPOSE

To discuss computed tomography (CT) evaluation of the etiology of vocal cord paralysis (VCP) due to thoracic diseases.

MATERIALS AND METHODS

From records from the past 10 years at our hospital, we retrospectively reviewed 115 cases of VCP that were evaluated with CT. Of these 115 cases, 36 patients (23 M, 13 F) had VCP due to a condition within the thoracic cavity. From these cases, we collected the following information: sex, age distribution, side of paralysis, symptom onset date, date of diagnosis, imaging, and primary disease. The etiology of VCP was determined using both historical information and diagnostic imaging. Imaging procedures included chest radiograph, CT of neck or chest, and esophagography or esophagoscopy.

RESULTS

Thirty-three of the 36 patients with thoracic disease had unilateral VCP (21 left, 12 right). Of the primary thoracic diseases, malignancy was the most common (19, 52.8%), with 18 of the 19 malignancies presenting with unilateral VCP. The detected malignant tumors in the chest consisted of thirteen lung cancers, three esophageal cancers, two metastatic tumors, and one mediastinal tumor. We also found other underlying etiologies of VCP, including one aortic arch aneurysm, five iatrogenic, six tuberculosis, one neurofibromatosis, three benign nodes, and one lung collapse. A chest radiograph failed to detect eight of the 19 primary malignancies detected on the CT. Nine patients with lung cancer developed VCP between follow-ups and four of them were diagnosed with a progression of malignancy upon CT evaluation of VCP.

CONCLUSION

CT is helpful for the early detection of primary malignancy or progression of malignancy between follow-ups. Moreover, it can reveal various non-malignant causes of VCP.

Vocal Fold Immobility: A Longitudinal Analysis of Etiology Over 20 Years

OBJECTIVES

To determine the current etiology of vocal fold immobility, identify changing trends over the last 20 years, and compare results to historical reports.

STUDY DESIGN

The present study is a retrospective analysis of all patients seen within a tertiary care institution between 1996 and 2005 with vocal fold immobility. The results were combined with a previous study of patients within the same institution from 1985 through 1995. Results were compared to the literature.

METHODS

The medical records of all patients assigned a primary or additional diagnostic code for vocal cord paralysis were obtained from the electronic database.

RESULTS

Eight hundred twenty-seven patients were available for analysis (435 from the most recent cohort), which is substantially larger than any reported series to date. Vocal fold immobility was most commonly associated with a surgical procedure (37%). Nonthyroid surgeries (66%), such as anterior cervical approaches to the spine and carotid endarterectomies, have surpassed thyroid surgery (33%) as the most common iatrogenic causes. These data represent a change from historical figures in which extralaryngeal malignancies were considered the major cause of unilateral immobility. Thyroidectomy continues to cause the majority (80%) of iatrogenic bilateral vocal fold immobility and 30% of all bilateral immobility.

CONCLUSIONS

This 20-year longitudinal assessment revealed that the etiology of unilateral vocal fold immobility has changed such that there has been a shift from extralaryngeal malignancies to nonthyroid surgical procedures as the major cause. Thyroid surgery remains the most common cause of bilateral vocal fold immobility.

Diagnostic Testing for Vocal Fold Paralysis: Survey of Practice and Evidence-Based Medicine Review

OBJECTIVES/HYPOTHESIS

Vocal fold paralysis continues to be a dominant topic in laryngology. Although the majority of cases can be attributed to a known etiology, a significant number of patients present without a clear precipitating event. Over 1,500 studies regarding vocal fold paralysis exist in the medical literature, although only a small percentage report on the use of serum or radiographic testing for the evaluation of idiopathic paralysis. Despite this, patients are routinely subjected to diagnostic evaluation to investigate the underlying cause. To characterize contemporary practice, a national survey of the American Broncho-Esophagological Association (ABEA) membership was undertaken. It is hypothesized that the current practice of diagnostic testing for idiopathic vocal fold paralysis is not well supported by an evidence-based medicine (EBM) review of the available medical literature.

STUDY DESIGN

The authors conducted a national survey, systematic EBM review of existing literature.

METHODS

Surveys were mailed to all active ABEA members; responses regarding practice specialization as well as serum/radiographic diagnostic preferences for idiopathic vocal fold paralysis were tabulated and subjected to statistical analysis. To compare contemporary practice with evidence in the available literature, an EBM review was first performed. Articles for evaluation were selected from a Medline search of English-language abstracts related to adult vocal fold paralysis. The publications were individually reviewed and an EBM level and grade were assigned and compared with the survey results.

RESULTS

Eighty-four of 249 active members responded with 76 (31%) replies submitted for analysis. Specific serum tests were advocated by 41 of 76 (54%) respondents, although the majority (52 of 65 [80%]) felt that they were only "occasionally" or "never" necessary. The most common tests were rheumatoid factor (38%), Lyme titer (36%), erythrocyte sedimentation rate (34%), and antinuclear antibody (33%). Fifty-one of 71(72%) felt that computed tomography (CT) was "always" or "often" necessary and 50 of 72 (69%) replied that chest radiography (CXR) was "always" or "often" necessary. There was no significant difference between CT and CXR ordering (P < .51). In contrast, magnetic resonance imaging (MRI) was described as "always" or "often" necessary in 28 of 71 (39%) of the surveys, significantly less than CT (P < .0001). There was no statistical impact of practice specialization on ordering of serum tests (P = .25) or imaging (P = .50 for CT; P = .46 for CXR; P = .45 for MRI). Following analysis of 1,510 vocal fold paralysis abstracts, 19 publications were found to be appropriate for an EBM review of serum testing with 15 available for review of radiographic imaging. Only one study presented level III evidence; the remainder were levels IV and V comprised of retrospective series and case reports. The evidence supporting serum or radiographic testing toward the evaluation of idiopathic vocal fold paralysis is given an overall grade of "C."

CONCLUSIONS

Serum and radiographic testing for the evaluation of vocal fold paralysis is supported by grade "C" evidence only. There are no existing prospective studies estimating the clinical impact of testing on diagnosis or patient outcome. Current practice, as estimated by a survey of the ABEA membership, is not well founded for serum testing and only by retrospective case series with regard to imaging. Further study into the nature of idiopathic vocal fold paralysis and outcomes assessment of diagnostic paradigms may improve clinical practice.

Vocal fold paralysis as a sign of chest diseases: a 15-year retrospective study

BACKGROUND

Vocal fold paralysis (VFP) is sometimes the only sign of chest diseases. However, some patients with VFP due to chest diseases are not diagnosed correctly at the first examination, which may leave the patients untreated for a long time. Depending on the situation, chest x-ray is not enough for detecting the primary lesion. The objective of this study was to discuss the diagnostic procedure for VFP based on the retrospective analysis of the cases.

METHODS

A total of 42 patients (29 males and 13 females) with VFP due to chest disease examined at the Department of Otolaryngology of Kyoto Prefectural University of Medicine between 1988 and 2002 were reviewed retrospectively.

RESULTS

Of the primary chest diseases, lung cancer (15 cases) was the most common, followed by thoracic aortic aneurysm (TAA) (9 cases), metastatic tumor from other regions (6 cases), pulmonary and mediastinal tuberculosis (TB) (5 cases), and esophageal cancer (4 cases). While the primary lesions were easily detected with chest x-ray in most of the cases, some lesions in the aortopulmonary window were difficult to detect. Contrast-enhanced computed tomography (CT) was useful to detect any mass in this region.

CONCLUSIONS

In the diagnosis of VFP due to chest diseases, chest x-ray was useful but not always enough for detecting the primary lesion. Necessity of further examinations including contrast-enhanced chest CT must be kept in mind for the cases with negative chest radiographs.

Reversible cochleo-vestibular deficits in two cases of jugular foramen tumor after surgery

Primary jugular foramen (JF) tumor, such as glomus jugular tumor or JF schwannoma, may manifest as a lower cranial nerve deficit; in addition, it can be accompanied by deafness or vertigo if it affects the cranial nerve (CN) VIII. Recently, we encountered JF schwannoma 1 and glomus jugulare tumor 1. Both cases invaded the adjacent cerebellopontine angle, leading to cochleo-vestibular deficits prior to the operation. After surgery, recovery of the audiovestibular function, including hearing, auditory brainstem response and caloric response, was anticipated in both patients. Therefore, cochleo-vestibular deficits in JF tumors can be attributed to compression neuropathy, rather than tumor infiltration.

The evolving etiology of bilateral vocal fold immobility

In the past, bilateral vocal fold immobility (BVFI) occurred most commonly after thyroidectomy. However, no large series documenting the etiology of adult BVFI has been published within the past fifteen years. This study reviews the etiologic patterns of BVFI at our institutions. We compare BVFI from before and after 1980. We also review combined studies of unilateral vocal fold immobility (UVFI) to compare and unilateral versus bilateral etiologic trends. In comparison with previously published series, fewer cases of BVFI present today as a complication of thyroid surgery and more as the result of malignancies and nonsurgical trauma. Unfortunately, BVFI caused by malignancy is not usually an initial sign of local disease, but an ominous sign of recurrence or metastases. In comparing UVFI and BVFI we found that thyroidectomy causes a higher percentage of BVFI than of UVFI. Over one-third of UVFI cases were caused by neoplasm which further underscores the potential seriousness of immobile vocal folds and the need for careful investigation.

Economic consequences of diagnostic imaging for vocal cord paralysis

RATIONALE AND OBJECTIVES

The purpose of this retrospective study was to estimate the economic consequences of evaluating suspected vocal cord paralysis with magnetic resonance (MR) imaging and computed tomography (CT).

MATERIALS AND METHODS

Reports from MR imaging (n = 30) or CT (n = 19) studies of the neck in 49 patients were retrospectively reviewed for causes of vocal cord paralysis. The patients were divided into high-suspicion (n = 20) and low-suspicion (n = 29) groups, based on the presence or absence of a clinically detectable abnormality other than vocal cord immobility. Clinic and inpatient charts were examined to determine the work-up in all cases. The Medicare Resource-based Relative Value Scale was used to estimate the costs of most procedures.

RESULTS

The high-clinical-suspicion group included nine true-positive, four false-positive, seven true-negative, and no false-negative cases. Further work-up was performed in seven true-positive, three false-positive, and one true-negative cases. The total cost of immediate diagnostic work-up in these 20 patients, including MR imaging and/or CT, was $20,737 ($2,304 per true-positive case). The low-suspicion group included two true-positive, nine false-positive, 18 true-negative, and no false-negative cases. Further work-up was performed in both true-positive, four false-positive, and two true-negative cases. The total cost of immediate diagnostic work-up in these 29 patients was $21,698, (mean, $748; $10,849 per true-positive case).

CONCLUSION

The average cost of finding space-occupying lesions in patients with vocal cord paralysis is more than 4.5 times higher in patients without suspicious antecedent clinical findings than in those with such a history. The benefits of obtaining negative findings and of detecting a small number of space-occupying lesions should be weighed against the costs of such examinations and of additional work-up for false-positive findings.

Evaluation and management of bilateral vocal cord immobility

Bilateral vocal cord immobility can be life threatening for some patients. Others, who have an open glottic chink, may have a breathy dysphonia, intermittent dyspnea, and stridor. These signs and symptoms may also be found in a number of other conditions that cause weakness or paradoxical motion of the vocal cords that mimics paralysis. These other conditions include central nervous system diseases, neuromuscular disorders, laryngospasm, and psychogenic disorders. In addition, patients with cricoarytenoid joint immobility or interarytenoid scar can also have similar symptoms at presentation. It is critical to consider the differential diagnosis of an assumed bilateral vocal cord paralysis and understand the management of paradoxical movement, weakness, joint fixation, interarytenoid scar, laryngospasm, and psychogenic disorders. The treatment for bilateral immobility should proceed only after a thorough evaluation, which might include electromyography and/or examination during general anesthesia under dense anesthetic paralysis. Reconstructive procedures are the treatments of choice, and destructive procedures should be chosen only as a last resort.

Changing etiology of vocal fold immobility

HYPOTHESIS

Vocal fold immobility is a sign of underlying disease. When the etiology remains unclear, evaluation may become time consuming and costly, and directed work-up imperative. This study examined the hypothesis that the etiologies of vocal fold immobility are changing, with extralaryngeal malignancies and nonthyroidectomy surgical trauma having become more common causes.

METHODS

A retrospective review of consecutive patients with vocal fold immobility who had an adequate workup to determine the etiology.

RESULTS

Three hundred ninety-seven cases with a determined etiology were identified, yielding 280 unilateral and 117 bilateral immobilities. The largest single category in unilateral immobility was nonlaryngeal malignancy--69 patients (24.7%)--80% of which were pulmonary or mediastinal, followed by 67 patients (23.9%) with immobility secondary to surgical trauma. Thyroidectomy accounted for only 8.2%. The leading cause of bilateral immobility was surgical trauma-30 patients (25.7%)--21 (18%) of whom had thyroidectomy. Acute and chronic intubation injuries accounted for 21 unilateral (7.5%) and 18 bilateral (15.4%) cases.

CONCLUSIONS

These data indicate a changing etiology of vocal fold immobility, with growing percentages of extralaryngeal malignancies and surgery-related injuries. These findings have implications for the timing and method of management based on anticipated outcome.