Clicking in the throat: cinematic fiction or surgical fact?

The complaint of a clicking in the throat when swallowing is uncommon but very discomforting and painful for those who experience it. It is such an unusual complaint that symptoms may be dismissed as psychogenic because a cause for the problem may not be readily apparent. We present a series of 11 cases in which all patients had an audible clicking or popping noise in the throat associated with neck and throat pain when swallowing or turning the neck. The most helpful diagnostic procedure was careful examination and palpation of the neck while the patient swallowed to localize the side and source of the clicking. Laryngeal computed tomographic (CT) scans helped in some cases to demonstrate thyroid-cartilage and/or vertebral body asymmetry. Each case was treated with surgery of the neck and larynx to trim the portion of the thyroid cartilage causing the clicking. In most cases the superior cornu of the thyroid cartilage projected posteriorly and medially. Surgery was successful in all cases to eliminate the symptoms. Though an uncommon complaint, our experience suggests that the clicking throat is a surgically treatable problem.

The importance of hyaluronic acid in vocal fold biomechanics.

OBJECTIVE: This study examined the influence of hyaluronic acid (HA) on the biomechanical properties of the human vocal fold cover (the superficial layer of the lamina propria). STUDY DESIGN: Vocal fold tissues were freshly excised from 5 adult male cadavers and were treated with bovine testicular hyaluronidase to selectively remove HA from the lamina propria extracellular matrix (ECM). Linear viscoelastic shear properties (elastic shear modulus and dynamic viscosity) of the tissue samples before and after enzymatic treatment were quantified as a function of frequency (0.01 to 15 Hz) by a parallel-plate rotational rheometer at 37 degrees C. RESULTS: On removing HA from the vocal fold ECM, the elastic shear modulus (G' ) or stiffness of the vocal fold cover decreased by an average of around 35%, while the dynamic viscosity (eta') increased by 70% at higher frequencies (>1 Hz). CONCLUSION: The results suggested that HA plays an important role in determining the biomechanical properties of the vocal fold cover. As a highly hydrated glycosaminoglycan in the vocal fold ECM, it likely contributes to the maintenance of an optimal tissue viscosity that may facilitate phonation, and an optimal tissue stiffness that may be important for vocal fundamental frequency control. SIGNIFICANCE: HA has been proposed as a potential bioimplant for the surgical repair of vocal fold ECM defects (eg, vocal fold scarring and sulcus vocalis). Our results suggested that such clinical use may be potentially optimal for voice production from a biomechanical perspective.

Gender-related differences of hyaluronic acid distribution in the human vocal fold.

OBJECTIVE: To quantify the distribution of hyaluronic acid (HA) within the normal human vocal fold and evaluate gender- and age-related differences. STUDY DESIGN: Prospective, cross-sectional study by age and gender groups using cadaveric vocal folds to study hyaluronic acid differences. METHODS: Twenty-five vocal fold halves obtained at autopsy were evaluated from nine adult male (age range, 34-52 y), seven adult female (age range, 21-41 y), four geriatric male (age range, 65-77 y), and five geriatric female (age range 65-82 y) subjects. Midmembranous vocal fold sections were stained for HA using the Muller-Mowry colloidal iron (acid mucopolysaccharide) stain with and without hyaluronidase. Digital imaging software was used to quantify the distribution of HA across the lamina propria at the vocal fold edge from superficial (subepithelial) to deep (vocalis muscle). RESULTS: A significant gender difference (P =.03) was noted in distribution when controlled for age. Combined, male subjects had a relatively constant distribution pattern throughout the depth of lamina propria. Female subjects showed relatively less HA in the first 15% of depth (most superficial) but showed more HA in the deeper 40% to 100% (toward vocalis muscle) than in male subjects. CONCLUSIONS: Important clinical implications may be extrapolated from our findings. First, relatively less HA in the most superficial area implies less protection from vibratory trauma and overuse and may explain in part why more female than male patients have phonotrauma to phonotraumatic lesions. Second, evaluating the distribution of HA in the normal human vocal fold allows more direction in our application of HA as a therapeutic lamina propria substitute in patients with voice disorders.

Senescent expression of genes coding collagens, collagen-degrading metalloproteinases, and tissue inhibitors of metalloproteinases in rat vocal folds: comparison with skin and lungs.

In humans, vocal tissue stiffness increases with age, suggesting a possible contribution of age-associated variations in vocal fold collagen turnover to voice senescence. The underlying mechanisms remain to be explored. With the use of reverse-transcriptase polymerase chain reaction (RT-PCR), collagen subtypes expressed in rat vocal folds were determined, and messenger RNA (mRNA) levels of collagens (types I, III, IV, and V), collagen-degrading proteinases (collagenase 3, gelatinase A and B), and tissue inhibitors of metalloproteinases (TIMP-1 to TIMP-4) were measured in vocal folds of neonatal, adult, and elderly rats. Collagens I, III-VIII, XV, XVII, and XVIII are abundantly expressed, whereas collagens II, IX, X, and XI are absent in rat vocal folds. Messenger RNA levels of collagens I, III, IV, and V and collagen-degrading proteinases in the vocal folds of the adult rats are significantly lower than those in the neonates. These mRNA levels show further decline in the vocal folds of the elderly rats, but only the decrease in mRNA levels of collagens I and V significantly differ from the adult levels. There are no marked age-related alterations in vocal fold levels of TIMP mRNAs, and the tissue variation in the gene expression of the aforementioned molecules is minute. Rat vocal folds display tissue-specific expression of collagen genes. Diminished gene expression for collagens and proteinases and unchanged gene expression for TIMPs indicate a slowdown in collagen turnover that may increase the cross-linking of collagen molecules. This observation may explain in part the stiffness that occurs with aging in human vocal folds.

An evaluation of the effects of two treatment approaches for teachers with voice disorders: a prospective randomized clinical trial.

Teachers commonly report voice problems and often seek medical assistance for voice-related complaints. Despite the prevalence of voice disorders within this occupation, there are no studies evaluating the effectiveness of treatment programs designed to remedy the voice problems of teachers. To assess the functional effects of two voice therapy approaches, 58 voice-disordered teachers were randomly assigned to 1 of 3 groups: vocal hygiene (VH, n = 20), vocal function exercises (VFE, n = 19), and a nontreatment control group (CON, n = 19). Subjects completed the Voice Handicap Index (VHI)-an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders-before and following a 6-week treatment phase. The VFE and VH subjects also completed a posttreatment questionnaire regarding the perceived benefits of treatment. Only the group who adhered to the VFE regimen reported a significant reduction in mean VHI scores (p <.0002). Furthermore, when compared to the VH group, the exercise group reported more overall voice improvement (p < .05) and greater ease (p < .02) and clarity (p < .01) in their speaking and singing voice after treatment. These findings suggest that the VFE should be considered as a useful alternative or adjunct to vocal hygiene programs in the treatment of voice problems in teachers.

Senescent expression of genes coding tropoelastin, elastase, lysyl oxidase, and tissue inhibitors of metalloproteinases in rat vocal folds: comparison with skin and lungs.

Histology studies indicate that vocal elastin content accumulates with age, suggesting possible contribution of elastin to age-associated voice changes. However, the underlying mechanism remains unclear. Using a reverse-transcriptase polymerase chain reaction (RT-PCR), mRNA levels of tropoelastin, elastase, lysyl oxidase, and tissue inhibitors of metalloproteinases (TIMP-1 to TIMP-4) were measured in vocal folds, tail skin, and lungs of rats at ages 1.5 +/- 0.5 weeks (neonatal), 6.0 +/- 0.5 months (adult), and 24 +/- 0.5 months (elderly). Vocal expression of both tropoelastin and lysyl oxidase peaks during the neonatal stage, followed by a significant decrease. Gene expression for elastase in the vocal folds of adult rats is not dissimilar to the neonatal levels. The levels in the elderly rots, however, show marked increase, to as much as 201% of the neonatal levels (p < .05). On the other hand, there is no conspicuous age-dependent variation in vocal expression of TIMPs. Gene expression of tropoelastin was similar in rat skin, lung, and vocal folds. In summary, compared to what is found in adult rats, there is a significant up-regulation in the expression of vocal elastase in the elderly animals in the presence of unchanged vocal expression of tropoelastin, lysyl oxidase, and TIMPs. As senescence occurs in both adult and elderly rats, tropoelastin and elastase expression are most affected. Gene expression for proteins affecting the amount of elastin in the vocal fold extracellular matrix does vary with age. These results may not be directly applicable to humans, because biomechanical forces experienced by human folds are likely different than those experienced by rats. However, in the absence of biomechanical forces experienced by humans, rat lungs, skin, and vocal folds display similar profiles of expression of genes coding the above-mentioned molecules. Similar profiles of expression for elastin genes across different tissue types not sharing similar environments suggests a common mechanism influencing senescence of these tissues. Human folds likely share a common similar mechanism of senescence with other organ systems, although organ-specific factors (oscillation, mechanical forces) are also likely operating.

Aesthetic comparison of wound closure techniques in a porcine model.

OBJECTIVE: To compare various commonly used closure techniques and their esthetic results. Also to look for differences in cost, time, and ease of use among the methods. DESIGN: A prospective comparison in a porcine skin model with a blinded assessment of outcomes. METHODS: Thirty 6-cm, full-thickness skin incisions were made on the back of two domestic white swine. Undermining was accomplished, and buried simple, interrupted, absorbable, braided (Polysorb, US Surgical) subdermal sutures were placed in a uniform fashion in each wound. The skin was then closed using one of the following five methods: running subcuticular 4-0 nylon, running subcuticular 4-0 absorbable monofilament (Biosyn, US Surgical), tissue glue (Dermabond, Ethicon), adhesive tape, or running subcuticular nylon with intradermal injection of hyaluronic acid. Nonabsorbable sutures and tape were removed on postoperative day 7, and photographs were taken at regular intervals during a 12-week healing period. Biopsies were taken from wounds in each group at 2 weeks and 12 weeks for histologic comparison. Independent observers evaluated the photographs, and an independent histologist evaluated the biopsies to look for differences in inflammation and scar formation. The surgeons who performed the wound closure rated the ease of use and amount of time required for each technique. RESULTS: Adhesive tape closure was faster and easier to perform. There were no significant differences among the adhesive tape, nylon, or absorbable suture groups regarding cosmetic appearance throughout the study period. The tissue glue wounds had more of a tendency to dehisce. Adhesive tape is less expensive than the other methods when material costs and operating room time are considered. CONCLUSION: Adhesive tape closure of surgical wounds is cosmetically acceptable, convenient, and saves both time and material costs. We recommend it as an alternative for closure of neck incisions.

Age- and gender-related collagen distribution in human vocal folds.

The composition of the lamina propria in human vocal folds has been shown to affect vocal performance. Collagen plays a significant role in the biomechanical effects of the lamina propria. Specifically, it lends tensile strength to the rapidly oscillating fold. We obtained from a state medical examiner 38 larynges from men and women in infant, adult, and geriatric age groups. We stained the vocal folds for collagen using a picric acid stain and studied them using an image analysis system. Distributions of collagen were measured from the superficial to deep layers (from epithelium to vocalis muscle) within the lamina propria. The data showed an increase in collagen content from infant to adult stages. Infant folds had about 51% of the collagen found in all adults and in geriatric patients (p < .001). There was no significant difference between adult and geriatric folds (p < .16). There was, however, a gender difference in the amount of collagen in both adult and geriatric specimens. Female adult and geriatric folds had about 59% of the collagen found in male adult and geriatric folds (p < .001). The distribution pattern of collagen showed that most of the collagen was present in the deep layer. From these data we conclude that there are age-related and gender-related differences between male and female infant, adult, and geriatric vocal folds. Stress-strain performance studies need to be correlated with histologic findings to better study the phonetic implications of these findings.

Cellular physiology of the vocal folds.

This article discusses cellular architecture and physiology relevant to phonation biology. The mucociliary blanket and its role in external vocal fold lubrication are presented. The epithelium, basement membrane zone, and lamina propria all have specific roles in oscillating tissue. Three cell types, fibroblast, myofibroblast, and macrophage, maintain important and unique roles. Protein turnover in the lamina propria is important, and slowing matrix turnover may be a leading factor in creating some of the characteristics associated with vocal senescence. Lastly, aspects of cellular health and cellular pathology are discussed.

Response to stimulation-evoked eccentric muscle contractions in hypertensive rats.

PURPOSE: The purpose of this study was to determine whether the functional deficits observed in the skeletal muscles of adult, spontaneously hypertensive rats (SHR) arise because of an inability of injured muscles to regenerate normally in the hypertensive environment. METHODS: Force decline and recovery were evaluated in SHR tibialis anterior (TA) at various times after a series of 192 eccentric contractions (EC). EC were produced by supramaximal electrical stimulation of the sciatic nerve in anesthetized rats. Experiments compared TA muscles in 3- and 6-month-old SHR with TA in age-matched, normotensive Wistar-Kyoto rats (WKY) after one or three exposures to the EC protocol. The repeat exposures were separated by 10 d. RESULTS: TA in SHR and WKY rats experienced a similar decline in strength and a similar level of recovery after one or three exposures to 192 EC. TA in both strains showed a similar 10-15% increase in dry weight and cross-sectional area after three exposures to the EC protocol. Contractile strength increased by 16-28% in WKY TA after three exposures to EC, but the increase was limited to 7% in 3-month SHR TA and was not evident in 6-month SHR TA, despite the 15% increase in muscle mass. CONCLUSIONS: The data indicate that muscle mass and strength can increase in response to electrically evoked EC and that an increase in strength can be significantly greater than an increase in mass after the first few exposures to EC in normotensive animals. Maintained hypertension does not increase the loss of contractile strength after vigorous EC but limits or prevents the EC-induced increase in muscle strength that accompanies repeated exposure to the protocol.

Impact of tympanostomy tubes on child quality of life.

BACKGROUND: The objective benefits of tympanostomy tubes for otitis media are well established, but the subjective impact of surgery on child quality of life (QOL) has not been systematically studied. OBJECTIVES: To determine the subjective impact of tympanostomy tubes on child QOL, and to compare the variability in QOL before surgery with that observed after surgery. DESIGN: Prospective, observational, before-and-after trial. SETTING: Fourteen referral-based pediatric otolaryngology practices in the United States. PATIENTS: Consecutive (64%) and convenience (36%) sample of 248 children (median age, 1.4 years) with otitis media scheduled for bilateral tympanostomy tube placement as an isolated surgical procedure. INTERVENTION: Tympanostomy tubes were inserted as part of routine clinical care. Validated measures of QOL (OM-6 survey), satisfaction with health care decision (Satisfaction With Decision Scale), and satisfaction with office visit; surveys were completed at baseline (visit 1), at surgery (visit 2), and after surgery (visit 3). MAIN OUTCOME MEASURES: Short-term changes in QOL before surgery (visit 1 to visit 2) and after surgery (visit 2 to visit 3). RESULTS: Changes in QOL before surgery were mostly trivial, and were smaller than changes observed after surgery (P<.001). Large, moderate, and small improvements in QOL occurred after surgery in 56%, 15%, and 8% of children, respectively. Physical symptoms, caregiver concerns, emotional distress, and hearing loss were most improved, but significant changes were also seen for activity limitations and speech impairment. Trivial changes occurred in 17% of children, and 4% had poorer QOL. Predictors of poorer QOL were otorrhea 3 or more days (10% of variance) and decreased satisfaction with surgical decision (3% of variance). Hearing status, child age, type of otitis media (recurrent vs chronic), and office visit satisfaction were unrelated to outcome. CONCLUSIONS: Tympanostomy tubes produce large short-term improvements in QOL for most children. The best outcomes occur when postoperative otorrhea is absent or minimal, and when parents are satisfied with their initial decision to have surgery. Further research is needed to document the long-term impact of tubes on child QOL.

Dissection plane of the human vocal fold lamina propria and elastin fibre concentration.

To determine whether a natural plane of dissection occurs in the normal human vocal fold, semi-blunt instruments (Bouchayer laryngeal dissectors) were used to dissect the lamina propria. The depth of the plane of dissection was correlated with the elastin fibre concentration to determine whether the plane occurred at a predictable point in the elastin concentration as it increased between the superficial and middle layers. Eight human larynges were dissected using an operative microscope. The dissection plane consistently occurred between 23-50% depth into the lamina propria. No consistent correlation was found with the elastin fibre concentration. The depth of the plane of dissection has an interesting association with age: dissection planes occurred more superficially in older specimens.

Preliminary report on hormone receptors in the human vocal fold.

UNLABELLED: There has been an ongoing effort to describe the physiologic factors associated with perceived and/or measured human voice changes that occur with age. In our study we focused on possible endocrine involvement on voice by using immunohistochemical staining to observe hormone receptor presence in vocal folds from 42 deceased subjects (fresh cadavers), male and female, ranging in age from 2 months to 82 years (average 37.7 years). On statistical analysis, age and gender were found to be associated with progesterone receptor staining of the glandular nuclei (young>old P = 0.013; male>female, P = 0.060). Gender was associated with androgen receptor staining in glandular cytoplasm (male>female, P = 0.014) and progesterone receptor staining in the epithelial cytoplasm (male>female, P = 0.039). No statistical significance was noted in other categories. CONCLUSION: Hormone receptors are found in the nucleus and cytoplasm of cells in the vocal fold with statistically significant differences in age and gender distribution.

Biomechanical and histologic observations of vocal fold fibrous proteins.

This article discusses the molecular composition of the vocal fold and the relationship of fibrous molecules to the biomechanical and physiological performance of the tissue. The components of the extracellular matrix may be divided into fibrous proteins and interstitial proteins. The fibrous proteins, consisting of collagens and elastins, are the focus of this report. Elastin concentration varies by tissue depth in the vocal folds. Variation of elastin by age is reported, but some controversy exists. The biomechanical terms of stress and strain (and stress-strain curves of human vocal folds) are related to the fibrous proteins of the vocal folds. The fibrous proteins, their role in stress, and their effect on the dynamic range of vocal pitch are presented.

Na-dependent changes in intracellular Ca in spontaneously hypertensive rat hearts.

To determine whether Na/Ca exchange is altered in primary hypertension, Na-dependent changes in intracellular Ca, ([Ca]i), were measured in isolated perfused hearts from Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Intracellular Na, (Nai, mEq/kg dry wt), and [Ca]i were measured by NMR spectroscopy. Control [Ca]i was less in WKY than SHR (176 +/- 18 vs 253 +/- 21 nmol/l; mean +/- S.E., P < 0.05), whereas Nai was not significantly different. One explanation for this is that net Na/Ca exchange flux is decreased in SHR. If this hypothesis is correct, the rate of Ca uptake in SHR should be less than WKY when Na/Ca exchange is reversed by decreasing the transmembrane Na gradient. The Na gradient was reduced by decreasing extracellular Na, ([Na]o) and/or by increasing [Na]i. To increase [Na]i, Na uptake was stimulated by acidification while Na extrusion by Na/K ATPase was inhibited by K-free perfusion. Seventeen minutes after acidification, Nai had increased but was not significantly different in SHR and WKY (18.0 +/- 2.3 to 57.4 +/- 7.6 vs 20.3 +/- 0.6 to 66.5 +/- 4.8 mEq/kg dry wt, respectively). Yet [Ca]i was greater in WKY than SHR (1768 +/- 142 vs 1201 +/- 90 nmol/l; P < 0.05). [Ca]i was also measured after decreasing [Na]o from 141 to 30 mmol/l. Fifteen minutes after reducing [Na]o, [Ca]i was greater in WKY than SHR (833 +/- 119 vs 425 +/- 94 nmol/l; P < 0.05). Thus for both protocols, decreasing the transmembrane Na gradient led to increased [Ca]i in both SHR and WKY, but less increase in SHR. The results are consistent with the hypothesis that Na/Ca exchange activity is less in SHR than WKY myocardium.

Severe pharyngeal stenosis treated with inferiorly based sternocleidomastoid myocutaneous flap.

Severe pharyngeal stenosis is a debilitating condition associated with apnea and dysphagia. Treatment options include local flaps and free mucosal grafts. We present 2 cases of severe stenosis. apparently from adenotonsillectomy, that failed more conservative repairs. Both were treated successfully with a sternocleidomastoid myocutaneous flap rotated in through a lateral pharyngotomy. No further treatment has been required. Technical considerations and operative planning are discussed.

Posterior wall augmentation for treatment of velopharyngeal insufficiency.

Velopharyngeal insufficiency (VPI) can be treated surgically with various operations. This article describes the use of a superiorly based folded pharyngeal flap for posterior wall augmentation to treat VPI. This is a retrospective study indicating that a folded flap to augment the posterior wall is likely to be as effective as other surgical techniques to treat small velopharyngeal gaps. Patients selected for this procedure had very good velar motion. Postoperative nasometric zoo passage scores improved by an average of 18 over preoperative scores. Additionally, a correlation was found between age and nasometry improvement after surgery. Younger patients did better. Patients in whom VPI was caused by adenoidectomy did well. The 2 syndromic patients did not do as well when treated with this type of operation.

Vocal fold proteoglycans and their influence on biomechanics.

OBJECTIVE/HYPOTHESIS: To examine the interstitial proteins of the vocal fold and their influence on the biomechanical properties of that tissue. STUDY DESIGN: Anatomic study of the lamina propria of human cadaveric vocal folds combined with some viscosity testing. METHODS: Identification of proteoglycans is performed with histochemical staining. Quantitative analysis is performed using an image analysis system. A rheometer is used for viscosity testing. Three-dimensional rendering program is used for the computer images. RESULTS: Proteoglycans play an important role in tissue biomechanics. Hyaluronic acid is a key molecule that affects viscosity. DISCUSSION: The proteoglycans of the lamina propria have important biological and biomechanical effects. The role of hyaluronic acid in determining tissue viscosity is emphasized. Viscosity, its effect on phonatory threshold pressure and energy expended due to phonation is discussed. CONCLUSION: Proteoglycans, particularly hyaluronic acid, play important roles in determining biomechanical properties of tissue oscillation. Future research will likely make these proteins of important therapeutic interest.

Experimental approaches to vocal fold alteration: introduction to the minithyrotomy.

Treatment of challenging laryngeal disorders, such as lamina propria loss or neuromuscular dysfunction, may require novel approaches and techniques. This paper discusses an evolution of experimental techniques for treatment of lamina propria loss and use of the minithyrotomy. These techniques have been used for surgical access for lamina propria substitution, as well as placement of stimulating electrodes. The minithyrotomy is tolerated well by patients, provides access for microscopic instruments with the surgeon's hand close to the tissue of interest, avoids intralaryngeal mucosal incisions, and lines up the direction of dissection in an anterior-to-posterior orientation. This orientation is favorable for particular situations herein discussed. We present anatomic and physiologic concepts relevant to the surgical treatment of lamina propria dysfunction, as well as presenting our clinical experience. This paper is not intended to state how these difficult problems should be handled, but rather, to present our experience in techniques that may prove useful through further development.

Age- and gender-related elastin distribution changes in human vocal folds.

The composition of the lamina propria in human vocal folds has been shown to affect vocal performance. Elastin plays a significant role in the biomechanical effects of the lamina propria. We obtained 19 larynges from the state medical examiner from subjects whose cause of death was unrelated to the trachea and laryngeal regions. The sample contained male and female subjects in the infant, adult, and geriatric age groups. We stained the vocal folds for elastin with Verhoeff's elastic tissue stain and studied them with use of an image analysis system configured for light microscopy. Distributions of elastin were measured from superficial to deep within the lamina propria (from epithelium to vocal muscle). These elastin distributions were then compared with the use of statistical software. The data showed that there was an increase in elastin content from the infant through geriatric stages. No gender-related differences were found. Infant folds had about 23% of the elastin found in adults, and geriatric subjects had about 879% of the elastin found in adults. Both of these results were statistically significant (p < 0.05). The distributions were consistent with previous observations that the lamina propria is a layered structure with most of the elastin present in the intermediate layer. This layer was larger in geriatric subjects than in adult and pediatric subjects. We observed that the fiber diameter appeared to be larger in geriatric subjects (this observation is currently being verified with electron microscopy) whereas smaller, spiraled fibers appeared in pediatric subjects.