Reliability for Identification of a Select Set of Temporal and Physiologic Features of Infant Swallows.

There is little reported evidence regarding the reliability of temporal and physiologic features of infant swallowing from videofluoroscopic swallowing studies (VFSS). The purpose of this retrospective study was to determine a reliable set of temporal and physiologic features from infant swallowing that can be measured from analysis of VFSS. Temporal and physiologic features for testing were determined from review of previously reported features of infant VFSS in the literature. Two novel analysts underwent three training sessions to learn and practice visual recognition of the proposed features. The two analysts then assessed 25 swallows from 10 total subjects' VFSS. To establish inter- and intra-rater reliability, calculation of Pearson's r was used for features that met criteria for parametric analysis and Spearman's rank correlation coefficient was used for the non-continuous features. Percent agreement was used to report on the reliability of the dichotomous features due to insufficient variability for Spearman's rho analyses. Fifteen of the 16 tested features were found to have acceptable inter- and intra-rater reliability measures, with each analyst achieving a correlation of 0.75 or higher. This project identifies 15 variables that can be reliably measured from infant VFSS. This information can be used to assist with determination of normal versus abnormal swallow features and in developing and testing therapeutic strategies for infants with dysphagia.

Influence of consonant voicing characteristics on sentence production in abductor versus adductor spasmodic dysphonia.

OBJECTIVES/HYPOTHESIS: This study evaluated the hypotheses that sentence production by speakers with adductor (AD) and abductor (AB) spasmodic dysphonia (SD) may be differentially influenced by consonant voicing and manner features, in comparison with healthy, matched, nondysphonic controls. STUDY DESIGN: This was a prospective, single blind study, using a between-groups, repeated measures design for the independent variables of perceived voice quality and sentence duration. METHODS: Sixteen subjects with ADSD and 10 subjects with ABSD, as well as 26 matched healthy controls produced four short, simple sentences that were systematically loaded with voiced or voiceless consonants of either obstruant or continuant manner categories. Experienced voice clinicians, who were "blind" as to speakers' group affixations, used visual analog scaling to judge the overall voice quality of each sentence. Acoustic sentence durations were also measured. RESULTS: Speakers with ABSD or ADSD demonstrated significantly poorer than normal voice quality on all sentences. Speakers with ABSD exhibited longer than normal duration for voiceless consonant sentences. Speakers with ADSD had poorer voice quality for voiced than for voiceless consonant sentences. Speakers with ABSD had longer durations for voiceless than for voiced consonant sentences. CONCLUSIONS: The two subtypes of SD exhibit differential performance on the basis of consonant voicing in short, simple sentences; however, each subgroup manifested voicing-related differences on a different variable (voice quality vs sentence duration). Findings suggest different underlying pathophysiological mechanisms for ABSD and ADSD. Findings also support inclusion of short, simple sentences containing voiced or voiceless consonants as part of the diagnostic protocol for SD, with measurement of sentence duration in addition to judments of voice quality severity.

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.

The application of tissue engineering procedures to repair the larynx.

The field of tissue engineering/regenerative medicine combines the quantitative principles of engineering with the principles of the life sciences toward the goal of reconstituting structurally and functionally normal tissues and organs. There has been relatively little application of tissue engineering efforts toward the organs of speech, voice, and hearing. The present manuscript describes a study that was conducted in which a biologic scaffold derived from porcine (pig) extracellular matrix (ECM) was used to repair the defect following a hemilaryngectomy procedure in dogs. The ECM-augmented repair was compared with a control standard strap muscle (STM) procedure. The animals were sacrificed after 24 weeks at which time anatomic and histologic analyses were conducted. The ECM repair resulted in a macroscopic and microscopic reconstruction of laryngeal tissue that was superior to that observed with the STM procedure. The importance of regenerated tissue having the same structural and functional characteristics of native tissue is emphasized. A discussion of the mechanisms of ECM remodeling is presented along with the implications of such remodeling in the repair of laryngeal structures.