Joel C. Kahane

Connective tissue changes in the larynx and their effects on voice

Many characteristics of the aging voice have been described in the literature. These features include pitch changes (1-3), irregularities in vocal fold vibration (4), glottal incompetency as reflected in air loss and breathiness (5), and voice production changes associated with laryngeal tension, pitch breaks, roughness, hoarseness, and harshness (5-7). The evidence thus far obtained indicates that both male and female voices age; however, changes are most evident in the male (2,3). Although the precise reasons for the aging of voice are far from being well understood, they undoubtedly relate to the manner and extent that tissues change within the larynx. Data from acoustic, physiologic, and perceptual studies suggest that the nature of these intrinsic changes are complex and probably multifactorial. During the past 30 years there has been a modest amount of research on the biological aspects of aging of the voice; however, activity has increased significantly in the last 15 years. Most work has dealt with various aspects of changes in the connective tissues of the larynx including cartilages (8-12), ligaments (10,11,13,14), articular surfaces (15,16), and the lamina propria of the vocal folds (10,11,14). Unlike the long established research on aging of connective tissue in the body, for which there is a vast literature (17), relatively little is known about the aging of connective tissue in the larynx. Such information would be valuable in explaining some of the mechanisms of aging and the resultant physical and mechanical changes that occur as a result of the aging process. This paper reviews research on age-related con-

Age-related changes in the vestibular folds of the human larynx: A histomorphometric study

Summary Age-related changes were investigated in the human vestibular folds of the larynx. Twelve male Caucasian larynges were obtained from autopsy and studied via light microscopy. The donors were free from head-neck pathologies or laryngeal trauma. Specimens included a 6-week-old infant, and at least one each from the second through eighth decades. Each specimen was decalcified and prepared for paraffin embedding and subsequent sectioning in the coronal plane at 6 μm. Sections were stained alternately with safronphloxine-hematoxylin and iron gallien elastic stains. Descriptive and quantitative data were obtained from light microscopy and planar morphometry using a computer image analysis system. Tissue changes included fatty infiltration of serous and mucous glands, fibrotic changes in connective tissue, and alterations in the distribution of mixed glands specific to serous/mucous ratios. Potential implications of findings to vocal function are discussed.

Vocal aging and adductor spasmodic dysphonia: response to botulinum toxin injection.

Aging of the larynx is characterized by involutional changes which alter its biomechanical and neural properties and create a biological environment that is different from younger counterparts. Illustrative anatomical examples are presented. This natural, non-disease process appears to set conditions which may influence the effectiveness of botulinum toxin injection and our expectations for its success. Adductor spasmodic dysphonia, a type of laryngeal dystonia, is typically treated using botulinum toxin injections of the vocal folds in order to suppress adductory muscle spasms which are disruptive to production of speech and voice. A few studies have suggested diminished response to treatment in older patients with adductor spasmodic dysphonia. This retrospective study provides a reanalysis of existing pre-to-post treatment data as function of age. Perceptual judgments of speech produced by 42 patients with ADSD were made by two panels of professional listeners with expertise in voice or fluency of speech. Results demonstrate a markedly reduced positive response to botulinum toxin treatment in the older patients. Perceptual findings are further elucidated by means of acoustic spectrography. Literature on vocal aging is reviewed to provide a specific set of biological mechanisms that best account for the observed interaction of botulinum toxin treatment with advancing age.

Exercise in Paleo-Otolaryngology: Head and Neck Examination of Two Egyptian Mummies

Two Ptolemaic period mummies underwent head and neck examination including high-resolution tomography and endoscopic rhinoscopy and cranioscopy. The anatomy demonstrated characteristic laryngeal calcification and sexual dimorphism. Pathologic findings consisted of severe dental disease and possible chronic ear disease. Postmortem changes revealed the entrance of the embalmers into the cranial cavity, but raised interesting speculation regarding the method of brain removal.

Blood supply to the nape-of-the-neck flap: implications from a fetal anatomical study.

The blood supply to the nape-of-the-neck flap was studied in 11 18-week-old fetuses by infusion of methyl methacrolate into the vascular system. Dissection of the posterior cervical region showed that the major blood supply to this area was through perforating vessels from the superficial portion of the ramus decendens of the occipital artery and the posterior auricular artery. Since a “named artery” was not found in the longitudinal axis of the flap, as is reported in the literature, it should be considered a cutaneous rather than an arterial flap. The findings of this study are consistent with classical anatomical descriptions about blood supply to this region. Collateral vascular pathways from the occipital artery and the costicervical trunk are discussed.

False Vocal Fold Characteristics in Presbylarynges and Recurrent Laryngeal Neuropathy

Objective: Conflicting data exist regarding false vocal fold (FVF) anatomy; it is unclear if this structure is an extension of the thyroarytenoid muscle or an independent muscle system. This confusion is amplified by diverse clinical findings in the setting of unilateral recurrent laryngeal neuropathy and presbylarynges. We sought to characterize FVF behavior in these contexts. Methods: Laryngoscopic/stroboscopic examinations from 11 patients with unilateral recurrent laryngeal nerve paresis and 12 patients with presbylarynges were reviewed by 4 laryngologists, blinded to the goal of the study but informed of diagnosis. Variables related to FVF structure and function at rest and during phonation were rated. Results: In recurrent laryngeal neuropathy, no significant association between atrophic/paretic vocal fold (VF) and FVF size was observed at rest (P = .69). During phonation, FVF compression was noted bilaterally; contralateral FVF hypertrophy was more common (P = .002). In presbylarynges, neither FVF size at rest (P = .86) nor compression during phonation (P = .37) was associated with the more atrophic VF; FVF compression/hypertrophy was common. Conclusions: Consistent with clinical dogma, FVF compression was more common contralateral to VF neuropathy. This finding, however, was inconsistent and may suggest individual variability in FVF innervation and/or morphology. Intra- and interrater reliability of these clinical findings was poor.