Role of Video-stroboscopy Vs Video-Laryngoscopy in Hoarseness of Voice

Abstract

Some pathologies of the larynx maybe missed on video-laryngoscopy which can be diagnosed on video-stroboscopy. Moreover, some pathologies can be diagnosed earlier, preventing reduced voice-related quality of life. Since the effective treatment of laryngeal pathologies is based on the correct diagnosis, this study was conducted to evaluate the added value of video-stroboscopy over video-laryngoscopy in patients with hoarseness of voice and to identify the pathologies in which video-stroboscopy has the maximum benefit over video-laryngoscopy. Prospective observational study of 76 patients presenting to out-patient department of otorhinolaryngology of our centre presenting with hoarseness of voice and fulfilling the inclusion criteria. Patients were subjected to thorough history taking and examination followed by video-laryngoscopy and video-stroboscopy by the same examiner. There was an addition in diagnosis on video-stroboscopy in 26 (34.21%) patients and a change in diagnosis in 29 (38.16%) patients. The maximum frequency of addition in diagnosis was seen in post-op vocal fold fibrosis (100%), Vocal nodules (66.66%) and the maximum frequency of change in diagnosis was seen in Presbylarynges, Rienke’s Edema and Muscle tension dysphonia (100% each). Early vocal nodule (54.54%) was the most common diagnosis reached on video-stroboscopy where video-laryngoscopy was inconclusive. Video-stroboscopy is an effective modality for the diagnosis of vocal fold lesions and must be used in conjunction with video-laryngoscopy for evaluation of patients presenting with hoarseness of voice of early diagnosis and treatment. In this study we have identified pathologies that benefit the maximum from the use of video-stroboscopy over video-laryngoscopy.

Clinical Significance

In this study we have identified pathologies that benefit the maximum from the use of video-stroboscopy over video-laryngoscopy

Introduction

Hoarseness is defined as—“A perceived rough, harsh or breathy quality to the voice” [1]. Reduced voice-related quality of life (QOL) is defined as a self-perceived decrement in physical, emotional, social or economic status as a result of voice-related dysfunction [2].

Hoarseness “is more prevalent in certain groups, such as teachers and voice professionals. It can affect all age groups and both genders. In addition to the impact on health, it affects the quality of life (QOL) [2].”

Hoarseness is often caused by benign or self-limiting conditions, but may also be the presenting symptom of a more serious or progressive condition, which requires prompt diagnosis and management. Hoarseness affects people differently. Some may have altered voice quality while others may experience problems with communication and diminished voice-related QOL.”

Video-laryngoscopy (VLS) is used to examine the larynx at the office with clarity and data preservation facility. It allows preferential visualization of specific regions of the larynx without compromising patient comfort in OPD [3]. VLS has been recommended for routine screening of laryngeal pathologies.”

Video-stroboscopy (VSS) “is another important modality for the evaluation of various cases of laryngeal pathologies. VSS allows the examiner to observe vocal fold vibration during sound production. This special viewing allows the evaluation of vocal fold (VF) vibratory parameters such as amplitude, mucosal wave, periodicity, phase symmetry, glottic closure, etc. As important as any of these aspects, VSS substantially improves the sensitivity of subtle laryngeal diagnosis [3].”

Some pathologies of the larynx maybe missed on video-laryngoscopy which can be diagnosed on video-stroboscopy. Moreover, some pathologies can be diagnosed earlier, preventing reduced voice-related quality of life. Since the effective treatment of laryngeal pathologies is based on the correct diagnosis, this study was conducted to evaluate the added value of video-stroboscopy over video-laryngoscopy in patients with hoarseness of voice and to identify the pathologies in which video-stroboscopy has the maximum benefit over video-laryngoscopy.

Materials and Methods

It was a prospective observational study conducted in tertiary care centre of eastern India from October 2020 to August 2022 on patients with hoarseness of voice coming to out-patient department of otorhinolaryngology. Institutional ethical committee (KIIT/KIMS/IEC/435/2020) approval was taken before starting of the study.

Inclusion Criteria

Patients of either sex of age between 18 and 60 years presenting to out-patient department of otorhinolaryngology with hoarseness of voice who gave written informed consent were included in our study.

Exclusion Criteria

Patients with any contraindication to video-laryngoscopy and video-stroboscopy or unwilling to give consent were excluded from our study.

Methodology

Consecutive sampling method was used and 76 patients presenting to out-patient department of otorhinolaryngology fulfilling the inclusion criteria were enrolled in the study after taking written informed consent. Patients underwent thorough history taking and clinical examination. Patients were evaluated with video-laryngoscopy and video-stroboscopy by the same examiner and diagnosis was reached independently and the results were recorded.

Local Anaesthetic (10% Lignocaine spray) was used in both procedures.

Video-laryngoscopy was done using a 4 mm, 70-degree rigid endoscope attached to a C mount High-Definition Camera and screen, in sitting position.

Video-stroboscopy examination was done using Atmos stroboscope system which consists of a 90-degree telescope, high illumination light source, camera, monitor and a microphone attached to telescope for recording voice signal. The procedure was performed in sitting position and patient was explained about the procedure. Examination was done by the rigid 90-degree Atmos^® stroboscope. With the vocal folds clearly visible at the centre field, the patient is asked to generate /ee/ sound. The strobe light was activated by pressing foot pedal. The examination was done at low, mid-range, and high frequency pitches as well as different loudness.

All the stroboscopic examinations were carried out by the same examiner. Stroboscopic parameters were analysed by the expert invigilator and documented using Stroboscopy Evaluation Form based on the evaluation format by Bruce J. Poburka and Rita R. Patel [4]. Parameters used are vocal fold edge, mobility, supraglottic activity, regularity, amplitude, mucosal wave, glottic closure, phase symmetry, vertical level, phase closure, non vibrating portion and non vibratory observations. (Annexure-1)

Statistical Analysis

Categorical variables were expressed as n (%). We calculated the additional diagnostic value of video-stroboscopy over video-laryngoscopy in hoarseness by comparing their findings. Stata version 14.2 (Stata Corp, College Station, TX, USA) was used for all statistical analysis.

Result

Video-Laryngoscopy

Out of a total of 76 patients as sample size, most frequent diagnosis on video-laryngoscopy was Unilateral vocal fold polyp in 20 patients (26.32%) followed by a report of Inconclusive/Normal study in 13 patients (17.11%). Unilateral vocal fold Glottic growth had 12 patients (15.79%). Bilateral Vocal nodule had 11 cases (14.47%) and 8 cases of unilateral vocal fold palsy were diagnosed (10.53%) and 6 cases of Unilateral Vocal fold cyst (7.89%). There were 3 cases in which thinned out vocal folds were visualized (3.95%). Single cases each (1.32%) of unilateral vocal fold thinning, sulcus vocalis and Vocal fold candidiasis were present. (Table. 1)

Table 1.

Frequency of various diagnosis under video-laryngoscopy

Final Diagnosis on Video-laryngoscopy	Frequency	Percentage
Bilateral Vocal Fold Thinning	3	3.95
Bilateral Vocal Nodule	11	14.47
Inconclusive/Normal	13	17.11
Sulcus Vocalis	1	1.32
Unilateral Vocal Fold Cyst	6	7.89
Unilateral Vocal Fold Growth	12	15.79
Unilateral Vocal Fold Palsy	8	10.53
Unilateral Vocal Fold Polyp	20	26.32
Unilateral Vocal Fold Thinning	1	1.32
Vocal Fold Candidiasis	1	1.32
Total	76	100

Video-Stroboscopy

Vocal Fold Polyp

There were total 19 unilateral vocal fold polyp patients (25%). Out of which 14(18.42%) were uncomplicated unilateral vocal fold polyp, 2(2.63%) were unilateral hemorrhagic vocal fold polyps, 2(2.63%) were unilateral vocal fold polyps with contralateral contact ulcers, 1 (1.32%) was large hemorrhagic vocal fold polyp with keratotic changes and 1(1.32%) was unilateral pedunculated vocal fold polyp with with features of laryngo-pharyngeal reflux disease (LPRD).

Vocal Fold Cyst

There were total of 15 (19.74%) unilateral vocal fold cyst patients. Out of these 6 were uncomplicated unilateral vocal fold cysts (7.9%), 8 were with contralateral contact ulcer (10.53%) and 1 with contralateral cystic changes (1.32%).

Bilateral Vocal Nodule

There were a total of 15(19.74%) bilateral vocal nodule patients out of which 6 had early nodular changes (7.89%) and 8 had organized nodules (10.53%). One patient (1.32%) had early nodular changes with androphonia.

Unilateral Vocal Fold Palsy

There were a total of 8(10.53%) vocal fold palsy patients out of which 6(10.53%) patients had adequate glottis closures (compensated) and 2 patients had inadequate glottic closures (2.63%).

Unilateral Vocal Fold Growth (Glottic)

There were a total of 5 patients of glottic growth involving unilateral vocal fold (6.58%). Out of these 4(5.26%) had fixed vocal folds and one (1.32%) had impaired vocal fold.

Presbylarynges

5 cases of presbylarynges were present. (6.58%)

Reinke’s Edema

2 cases of Reinke’s Edema were present (2.63%).

Sulcus Vocalis

2 cases of sulcus vocalis (2.63%).

Normal Study

2 cases were reported as normal (2.63%).

Muscle Tension Dysphonia (MTD)

Single case of MTD (1.32%).

Postop Vocal Fold Fibrosis

Single case of post-op vocal fold fibrosis (1.32%).

As seen in the given Table 2.

Table 2.

Frequency of various diagnosis under video- stroboscopy

Final diagnosis on video-stroboscopy	Frequency	Percentage
Bilateral vocal nodule (Early)	6	7.89
Bilateral vocal nodule (Organized)	8	10.53
Bilateral vocal nodule (Early with Androphonia)	1	1.32
Muscle Tension Dysphonia	1	1.32
Normal Study	2	2.63
Post Operative Vocal Fold Fibrosis	1	1.32
Presbylarynges	5	6.58
Reinkes Edema	2	2.63
Sulcus Vocalis	2	2.63
Unilateral Vocal Fold Cyst	6	7.90
Unilateral Vocal Fold Cyst (With Contralateral Contact Ulcer)	8	10.53
Unilateral Vocal Fold Cyst (With Contralateral Cystic Changes)	1	1.32
Unilateral Vocal Fold Growth (With Fixed Vocal Fold)	4	5.26
Unilateral Vocal Fold Growth (With Impaired Vocal Fold)	1	1.32
Unilateral Vocal Fold Palsy	6	7.89
Unilateral Vocal Fold Palsy (With Inadequate Glottic Closure)	2	2.63
Unilateral Vocal Fold Polyp	14	18.42
Unilateral Vocal Fold Polyp (Hemorrhagic)	2	2.63
Unilateral Vocal Fold Polyp (Large Hemorrhagic with Keratotic Changes)	1	1.32
Unilateral Vocal Fold Polyp (With C/L Contact Ulcer)	2	2.63
Unilateral Vocal Fold Polyp (Pedunculated with Laryngopharyngeal Reflux Disease)	1	1.32
Total	76	100

Added Value of Video-stroboscopy

Addition in Diagnosis

There was an addition in diagnosis in 26 (34.21%) patients. Highest percentage of patients in which added value was seen was post-op vocal fold fibrosis that is in 1 out of 1 patient (100%).Added value in 10 out of 15 patients (66.66%) of Vocal fold nodule, 1 out of 2 patients (50%) of Sulcus Vocalis, 8 out of 19 patients (42.10%) of Vocal fold polyp, 2 out of 8 patients (25%) of Vocal fold palsy, 3 out of 15 patients (20%) of Vocal fold cyst, 1 out of 5 patients (20%) of Vocal fold growth was seen. (Figure 1)

Fig. 1.

Percentages of Cases with Added Value of Video-stroboscopy in Respective Pathologies (Post-Op: Post-Operative; B/L: Bilateral; U/L: Unilateral; VF: Vocal Fold)

Change in Diagnosis

There was change in diagnosis in 29 patients (38.16%). Following pathologies were misdiagnosed on Video-laryngoscopy.

5 out of 5 patients of Presbylarynges (100%), 2 out of 2 patients of Reinke’s oedema (100%), 1 out of 1 patient of Muscle Tension Dysphonia (100%), 11 out of 15 patients of vocal fold cyst (73.33%), 1 out of 2 patients of sulcus vocalis (50%), 6 out of 15 patients of bilateral vocal nodule (40%), 4 out of 19 patients of vocal fold polyp (21.05%). (Figure 2).

Fig. 2.

Percentages of cases with change in diagnosis in respective pathologies. (B/L: Bilateral; U/L: Unilateral; VF: Vocal Fold)

Discussion

This study consists of 76 cases of various laryngeal pathologies. “All the cases were presented with change in voice. All cases of laryngeal pathologies were evaluated by history, VLS and VSS in the same hospital visit by the same ENT surgeon. This was done to reduce human error in laryngeal evaluation. During the assessment, both benign as well as malignant laryngeal pathologies have been evaluated thus including most prevalent conditions.”

VLS is the basic procedure for examination of the larynx. “However, certain vocal fold vibratory parameters such as amplitude, mucosal wave, periodicity, phase symmetry, glottic closure, etc. are still difficult to visualize on VLS. For this purpose, stroboscopes have been introduced in laryngeal evaluation.

Since “VSS can assess the above-mentioned factors, it has been established as a superior diagnostic tool as compared to VLS. VSS is the investigatory tool of choice for assessing the finer characteristics of the VC movements. This has a great contribution to judge the severity and progression of the disease. This alters the line of management of the disease leading to a better outcome. Our stroboscopic assessment protocol was based on the evaluation format by Bruce J. Poburka and Rita R. Patel [4].

The results of the present study were similar to the one carried out by Satallof et al. [5] in which VSS altered 18% of the diagnoses made by VLS.VSS also gave additional information in 29% of cases.

Kaushik et al. [6]. reported that the diagnoses of 32.50% of cases changed on evaluation by VSS. Also, additional diagnosis was made for 7.50%cases that were incompletely diagnosed on VLS. A study by “Ahmad [3] revealed that VSS altered the diagnosis in 19% of cases. Casiano et al. [7] conducted a study that showed that VSS altered the diagnosis in 14% of all cases. The findings of these studies support VSS as a superior diagnostic modality as compared to VLS.”A study conducted by “Printza et al. [8] showed that VSS altered the diagnosis in 4.7% of the cases and contributed to the initial diagnosis in 32.20%.”

Because VLSS aids in the detection of disorders related to the finer properties of the VC, it is therefore more effective to VLS as a diagnostic method, as demonstrated by the findings of the current investigation and the literature review. The VLS misses these. Evaluation of the vibratory characteristics of the vocal cord (VC), including magnitude, mucosal wave, regularity, phase symmetry, glottic closure, etc., is possible with this unique sight. VLSS significantly raises the sensitivity of minor laryngeal diagnosis, which is as significant as any of these factors combined.

Conclusion

Taking all of the previous studies and the current one into account, it can be said that Video-stroboscopy is an accurate, efficient, and better way to diagnose benign and malignant laryngeal pathologies than other methods. In this study we find that video-laryngoscopy is a good screening tool for laryngeal pathologies, however for pathologies affecting the vocal fold, it can miss diagnosis like early nodular changes, presbylarynges, rienke’s edema, muscle tension dysphonia and vocal fold cysts. Video-stroboscopy also gives added value to other pathologies like post-op Vocal fold fibrosis, vocal nodules and vocal fold cysts. Hence it must be used in conjunction with VLS for evaluation of hoarseness of voice wherever possible.

Author Contributions

Arnav Bharatendu Kapoor– Data curation, methodology, investigation, writing original draft. Nishikanta Pradhan– Methodology, formal analysis. Ananya Patra– Data curation, writing review and editing. Shubham agrawal- Visualization, validationKabikanta Samantaray– Conceptualization, Formal analysis, Project administration

Declarations

Conflict of Interest

There was no conflict of interest before, during or after the completion period of the entire study.