Structural and Anatomic Laryngeal Measurements in Geriatric Population Using MRI

Effect of Aging on the Vocal Muscle

INTRODUCTION

Sarcopenia is a common and natural condition in the elderly, and leads to loss of muscle mass and function. In the presbylarynx there is atrophy of the vocal folds, however the degree of vocal muscle atrophy is poorly studied and the results are contradictory.

AIMS

The aim of this study was to evaluate the effect of aging on the vocal muscle (thyroarytenoid muscle).

METHODS

Thirteen larynxes removed during necropsy from 13 cadavers were included into two age groups: Control group - G1 (n5), between 25 and 40 years; Elderly Group - GI (n-8), aged 70 years or older. The vocal folds were dissected and prepared for scanning electron microscopy, ensuring a cross-section in the musculature area to allow measurements of muscle fiber parameters. Images were analyzed and photographed at different magnifications. Through the ImageJ software, ten distinct fields of each part were selected. Parameters studied:  area, perimeters and diagonals of the thyroarytenoid muscle bundles of both groups.

RESULTS

The cross-sectional areas, perimeters and diagonals of the muscle fibers of the thyroarytenoid muscle of the elderly group were significantly smaller than those of the control group.

CONCLUSION

We demonstrated that the vocal muscle is affected in the presbylarynx, with a reduction of its muscle fibers, corresponding to muscle atrophy. However, these findings may not be directly related to vocal symptoms because the patient may develop muscle compensatory mechanisms capable of reducing glottic insufficiency.

Correlation of Glottic Gap and Voice Impairment in Presbyphonia

OBJECTIVE/HYPOTHESIS

The objective of this study was to investigate the glottic gap area as a significant marker for the severity of presbyphonia as it relates to patient-reported outcome measures (Voice Handicap Index-10 [VHI-10]) and stroboscopic findings.

STUDY DESIGN

Retrospective case-control study conducted in an academic tertiary voice center.

METHODS

Patients seen at a tertiary voice clinic who were diagnosed with presbyphonia without other organic laryngeal pathology from January 2014 to December 2017 were included. Clinical data and laryngeal videostroboscopy videos were collected. Still images at the point of vocal process approximation during adduction were captured, and the glottic gap area was measured using ImageJ. These were compared to a control cohort. Correlations were made using Wilcoxon rank sum test, Mann-Whitney U test, and Pearson correlation coefficients.

RESULTS

Thirty-three patients were included. Inter-rater reliability of glottic area measurement was strong (intraclass correlation coefficient = 0.73, P < .001). Compared to controls, presbyphonia patients had a larger glottic gap area (P < .001) and greater open-phase quotient on laryngeal videostroboscopy (P < .001). Larger glottic gap area did not correlate with patient-reported vocal function as measured by VHI-10 (P = .79) and did not correlate with presence of secondary muscle tension dysphonia (P = .99). In the presbyphonia cohort, the glottic gap area did not correlate with age (P = .29).

CONCLUSIONS

Glottic gap area at the point of vocal process approximation during phonation can be reliably measured. Patients with presbyphonia have a larger glottic gap area and greater open-phase quotient on stroboscopy, but these do not correlate with patient-reported voice impairment or the presence of secondary muscle tension dysphonia (MTD). These data suggest that dysphonia severity in presbyphonia is not fully explained by a glottic gap or secondary MTD alone.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1594-1598, 2021.

Volumetric Analysis of the Vocal Folds Using Computed Tomography: Effects of Age, Height, and Gender

OBJECTIVE

The goal of this study was to use computed tomography (CT) volumetric analysis to assess the effect of age, gender, height, body mass index (BMI), and ethnicity on vocal fold volume in patients with normal larynges.

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

Vocal fold length, width, and height were measured in a total of 105 patients without a history of laryngeal or thyroid pathology on thin-section soft-tissue neck CTs. The product of the three dimensions was used to calculate vocal fold volume. Simple and multiple linear regression analyses were used to assess for an association between vocal fold volume and age, gender, height, BMI, and ethnicity. Intraclass correlation coefficients (ICCs) were estimated to evaluate the degree interobserver and intraobserver agreement.

RESULTS

Vocal fold volume was not associated with age, BMI, or ethnicity. Gender-adjusted height (P = .002) and height-adjusted gender (P = .016) were significantly associated with volume. Height remained significantly associated with volume after stratifying by gender (P < 0.001). There was moderate-to-good correlation in both interobserver (ICC = 0.690 to 0.761) and intraobserver (ICC = 0.733 to 0.873) agreement.

CONCLUSION

Age was not associated with vocal fold volume, which is in accordance with several prior negative studies. Age-related vocal fold atrophy may not substantially contribute to presbyphonia symptoms, but other processes such as changes in the extracellular matrix may play a larger role. However, both gender and height were independently associated with vocal fold volume.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E240-E247, 2021.

Sexual Dimorphism in Laryngeal Volumetric Measurements Using Magnetic Resonance Imaging

The objective of this study is to investigate the dimensional and volumetric measurements in the thyroarytenoid (TA) muscle in men and women using magnetic resonance imaging (MRI). The hypothesis is that there is a gender-related difference in these measurements. A retrospective chart review of 76 patients who underwent MRI of the neck at the American University of Beirut Medical Center was conducted. The dimension and volume of the right and left TA muscle were measured on axial and coronal planes short tau inversion recovery images. Male and female groups were compared with respect to demographic data and MRI findings using parametric and nonparametric tests. The mean length of the thyro-arytenoid muscle in males was larger than that in females on the right (males 2.44 [0.29] cm vs females 1.70 [0.22] cm) and on the left (males 2.50 [0.28] cm vs females 1.72 [0.24] cm) reaching statistical significance (P < .001). The mean width of the thyro-arytenoid muscle in males was larger than that in females on the right (males 0.68 [0.13] cm vs females 0.59 [0.11] cm) and on the left (males 0.68 [0.12] cm vs females 0.57 [0.12] cm) reaching statistical significance (P < .001). The mean height of the thyro-arytenoid muscle in males was larger than that in females on the right (males 1.05 [0.21] cm vs females 0.95 [0.12] cm) and on the left (males 1.05 [0.21] cm vs females 0.95 [0.12] cm) reaching statistical significance (P < .01 on the right and P < .05 on the left). The volume of the thyroarytenoid muscle in males was larger than that in females on the right (males 0.86 [0.25] mL vs females 0.48 [0.15] mL) and on the left (males 0.89 [0.27] mL vs females 0.48 [0.17] mL) reaching statistical significance (P < .001). The results of this investigation clearly indicate a significant difference in these measurements between men and women.

Volumetric analysis of vocal fold atrophy via magnetic resonance imaging

Objective

To quantitatively test the hypothesis that older patients have increased thyroarytenoid muscle atrophy by comparing thyroarytenoid muscle volumes across different age groups.

Methods

A retrospective chart review was conducted. The study included 111 patients with no history of laryngeal pathology. Two investigators reviewed magnetic resonance imaging studies of these patients and manually traced the thyroarytenoid muscles on multiple slices bilaterally. Thyroarytenoid muscle volumes were then computed using imaging analysis software. Patients were stratified into three age groups (18–50 years, 51–64 years, and 65 years or older) for comparison.

Results

Intra- and inter-rater reliabilities were excellent for all measurements (intraclass correlation co-efficient > 0.90). There was no statistically significant difference in the mean volumes of left and right thyroarytenoid muscles in all age and gender groups.

Conclusion

Given the lack of statistically significant difference in thyroarytenoid muscle volume between age groups on magnetic resonance imaging, the prevailing assumption that age-related thyroarytenoid muscle atrophy contributes to presbyphonia should be re-examined.