The posterior glottis: structural and clinical considerations.

Despite the presence of a number of good publications during the past two decades, the posterior glottis (PG) is still not clearly appreciated in clinical laryngological practice. This study focuses on searching the literature to find out the present day awareness of the PG, as well as highlighting some of its clinical features. The investigation proceeds with two main sections: (1) critical analysis of the literature on the PG during the last 50 years (2) describing the clinical appearance and behavior of the PG in 100 normal subjects. Results of section 1 illustrate the limited awareness in the literature of the existence of PG as a distinct part of the human larynx. Results of section 2 illustrate some misconcepts related to the PG as inter-arytenoid pachydermia, change of voice with lesions in the PG. Discussion elaborates on the significance of the findings and attempts to clarify certain misconcepts about the PG, its structure, function, and clinical features. In the light of the data collected from the literature regarding the dimensions of the PG, a set of recommendations were proposed regarding the optimal sizes of the endotracheal tubes in both sexes.

The Arabic vowels: features and possible clinical application in communication disorders.

UNLABELLED: Most scholars, old and modern, agree that the vowel system of the Arabic language is composed of 3 vowels only, namely /i/, /ε/ and /u/. The spoken Cairo dialect suggests that there are 6 identifiable vowels, with a short and long variant for each. OBJECTIVE: The aim of this study is to test the validity of the notion that there are 6 × 2 distinct vowels, with a more central one. SUBJECTS AND METHODS: Spectral analysis was used to measure F(1) and F(2) for the vowels of 14 real words. Data was collected from 60 healthy adult informants, 30 males and 30 females. They were native Egyptians speaking the colloquial Cairene dialect. RESULTS: The values of the 6 long and short vowels plus the central one are presented. A significant difference was found between each of them. The long and short vowels differed only in the duration but did not differ in their formant values. CONCLUSION: The study illustrates the distinctive features of the vowels of the Arabic language. Each of the 7 vowels represents a distinct entity. This will have important implications in assessment and management of language, speech and voice disorders in children and adults.

Gastroesophageal reflux/laryngopharyngeal reflux disease: a critical analysis of the literature.

Despite the wealth of publications on the topic of gastroesophageal reflux and its variants, there are still many unsettled questions before one accepts the prevalent cult of "reflux disease". This study is summarizing the results of the critical analysis of the literature, 436 articles,during the last 30 years. The golden test to identify the patient group suffering from this rather common phenomenon is still lacking. The claimed extra-esophageal manifestations especially in the larynx are non-specific and may be caused by other factors well-known within the domain of vocology. The response to therapeutic intervention still lacks serious well-controlled studies to allow drawing reasonable conclusions. An outstanding feature of the publications is that most of them fall in the category of "review". It seems that there is a tendency to perpetuate the concept without objective criticism. Following the analysis, a recommendation for anew plan of original well-controlled multi-center studies is highlighted.

Aerodynamics of the pseudo-glottis.

OBJECTIVE: The aim of this work is to study the hitherto unclear aerodynamic parameters of the pseudo-glottis following total laryngectomy. These parameters include airflow rate, sub-pseudo-glottic pressure (SubPsG), efficiency and resistance, as well as sound pressure level (SPL). PATIENTS AND METHODS: Eighteen male patients who have undergone total laryngectomy, with an age range from 54 to 72 years, were investigated in this study. All tested patients were fluent esophageal 'voice' speakers utilizing tracheo-esophageal prosthesis. The airflow rate, SubPsG and SPL were measured. RESULTS: The results showed that the mean value of the airflow rate was 53 ml/s, the SubPsG pressure was 13 cm H(2)O, while the SPL was 66 dB. The normative data obtained from the true glottis in healthy age-matched subjects are 89 ml/s, 7.9 cm H(2)O and 70 dB, respectively. Other aerodynamic indices were calculated and compared to the data obtained from the true glottis. CONCLUSION: Such a comparison of the pseudo-glottic aerodynamic data to the data of the true glottis gives an insight into the mechanism of action of the pseudo-glottis. The data obtained suggests possible clinical applications in pseudo-voice training.

Public health impact of hearing impairment and disability.

UNLABELLED: This presentation of the public health impact of hearing impairment highlights the important elements of interaction between the disability and community. OBJECTIVES: Retrospective study to identify the size of the problem of hearing loss, illustrating not only the magnitude but also the serious effect of the lack of reliable data concerning this matter. It highlights the challenges met within a mid-economy community regarding the handling of the impact of the disability. The Egyptian data is given as an example of the situation in a mid-economy community. STUDY DESIGN: A brief introduction of some epidemiological factors of hearing impairment is presented including the size of the problem in Egypt. Data of the neonatal hearing screening program of the Audiology Unit, Ain Shams University, is presented. The impact of the disability is then discussed in relation to the age of onset and the degree and type of hearing loss. This is followed by the description of the nature and effect of the disability in the different age groups. A discussion of the various factors that may modify the capability of the community to deal with such disability follows. This includes various economic indices with their possible limitations on the part of the community. Such a briefing illustrates the challenges met in the rehabilitation of the deaf and the hearing-impaired in a developing mid-economy country. The broad lines of the management of the problem both at the prophylactic as well as the rehabilitative levels are discussed. A final remark on recommendations and possible future development in a developing country is presented.

Multidimensional analysis of speech of hearing impaired children.

The character of speech of hearing impaired children was evaluated via multidimensional protocol in order to provide sensitive and quantitative measures of assessment. 20 children (9 males and 11 females) with moderate to severe hearing impairment, were studied. The protocol of assessment included auditory perceptual assessment (APA) (documented by high fidelity audiorecording), audiological assessment, formal testings, aerodynamic assessment and acoustic analysis. APA showed addected vowels (90%), affected suprasegmental phonology; rate (60%), stress (80%), tonality (85%); decreased resonance (15%); affected voice (45%) and affected intelligibility (85%). Aerodynamic results showed highly significant increase in the subglottic pressure, highly significant decrease in glottal resistance and glottal efficiency, indicating a possible breakdown in respiratory, phonatory and articulatory coordination. Spectrographic results showed significant increase in the syllable duration; vowel duration and sentence duration. Visi-Pitch results showed highly significant increase in the intensity, significant decrease in the maximum fundamental frequency (Fo) and highly significant decrease in the percent pause. The accoustic findings may represent a quantitative correlate to some of the subjective observations of APA.

Mechanism of glottic closure in a model of unilateral vocal fold palsy.

The effect of extrinsic laryngeal muscles on the position of the paralyzed vocal fold (VF) was analyzed in 13 adult human larynges. Fresh specimens were suspended within a specially constructed frame designed to reproduce the three-dimensional position of the VF, and to allow for simulation of laryngeal muscle action, in five successive experiments resembling: 1) complete vagal paralysis and contralateral adduction, 2) laryngeal elevation added, 3) vocal fold stretching added, 4) contralateral laryngeal tilting added, and 5) ipsilateral cricothyroid muscle activation added. We observed an incremental narrowing of the middle and posterior glottic gaps from 3.9 mm and 6.8 mm respectively in experiment 1 to 1.1 mm and 1.9 mm in experiment 5. Glottic closure in the final experiment was associated with rotation of the glottis to the "paralyzed" side in the axial plane, and contralateral laryngeal tilting in the coronal plane. We show that extrinsic laryngeal muscles can help to close a paralytic gap; crossing of the contralateral VF past the midline was not observed in any of the experiments.

The accent method of voice therapy: effect of accentuations on FO, SPL, and airflow.

The effect of the increased flow rate (delta U) in response to the Accent Method exercises on fundamental frequency (FO) and sound pressure level (SPL) was studied in three subjects (professionally trained, trained, and untrained in this method). In all the subjects, the rhythmic accentuated exercises produced a variable degree of increase in FO (delta FO) and SPL (delta SPL). The professionally trained subject showed greater delta FO and delta SPL in response to the delta U in the fastest tempo, which requires higher skills. Both trained subjects showed a greater correlation between delta U and both delta SPL and delta FO, as well as between delta FO and delta SPL, as compared to the untrained subject. The effects of the accentuated exercises on FO and SPL in response to the increased airflow rate (delta U) thus appear to demonstrate the treating effectiveness of the Accent Method.

Fundamental frequency stability in functional dysphonia.

Functional dysphonia is a term applied to voice disorders for which there is an absence of apparent structural change in the larynx. The aim of this work was to investigate how functional dysphonia may differ acoustically from other types of dysphonia. Fundamental frequency profiles for steady vowels were generated using a software program called GLIMPES (Glottal Imaging by Processing External Signals). The fundamental frequency variations were found to be unimodal in normal individuals. In contrast, the variations for dysphonic patients were sometimes bi-modal or multi-modal due to the presence of subharmonics or low-frequency modulations. The appearance of these patterns was generally related to the severity of the dysphonia rather than to its etiology.

Pattern of gross displacement of the vocal fold in adduction and abduction movements.

The pattern of gross displacement of the vocal fold during adduction and abduction was studied in 4 adult fresh human larynges (2 males and 2 females). Markers were placed on specific sites along the edge of the vocal fold. Preliminary observations showed upward and lateral movement of the free edge during abduction. The vocal fold as a whole glides into and fills the cavity of the laryngeal ventricle. To quantify this observation 14 larynges (8 males and 6 females) were studied, using a technique designed to measure vertical and horizontal displacement of the vocal fold. An average of a 1.34 mm elevation and 4.43 mm lateral excursion were observed at midvocal fold level. A model for studying the pattern of vocal fold abduction is suggested and discussed.

Histo-anatomical structure of the human laryngeal ventricle.

A study of the microstructure of the human laryngeal ventricle and ventricular band was carried out on 20 human larynges in an attempt to up-date and elucidate the function of these structures. Celloidin and paraffin whole organ coronal serial sections were studied to clarify the epithelial, glandular as well as muscular structures of the ventricle and ventricular band. The present study showed that the superior thyro-arytenoid muscle was bilaterally present in 80% of cases. On the other hand, the ventricularis muscle was bilaterally present in 95% of cases. These ventricular muscular elements have been reported differently in the literature. The functional significance of these variations are discussed. The opening of the saccule into the ventricle is guarded anteriorly by the ventriculo-saccular fold. This fold was present in 19 out of 20 larynges. Neither the percentage of its presence, nor its orientation to the saccular opening has been reported in the literature. The function of this structure is discussed in the light of the present data.

Dominant functions of right versus the left hemisphere.

The aim of this work was to study the function of the left and right cerebral hemispheres concerning linguistic, musical and cognitive abilities, through the evaluation of the deterioration of these domains following lesions of either hemisphere. The study was carried out on 80 subjects (60 males, 20 females) with a mean age of 48 years. Subjects were categorized into four groups, 20 in each. Group I had left brain lesion with dysphasia; group II, left brain lesion without dysphasia; group III, right brain lesion without dysphasia; group IV, control. Patient's evaluation included a dysphasia test, psychometric battery, tests for musical abilities, brain CT scanning and EEG. Group I showed deterioration in the linguistic abilities, while groups II and III had intact abilities. Deterioration in musical abilities was noticed in group III, with normal scores in groups I and II. There was deterioration of the intellectual abilities in all patients' groups, to varying degrees. The significance of the results is discussed.

Ultrastructural features of vocal fold nodules and polyps.

Earlier investigation did not show any clear distinctive pathological features that differentiate vocal polyps from vocal nodules. The light microscopic distinctive features between the two lesions point in the direction of a more pronounced epithelial reaction and a more fibrous stromal change in vocal nodules. In the present study, 19 vocal polyps and 11 vocal nodules were subjected to ultrastructural examination aiming at finding distinctive features that may be pathognomic for each of these clinically distinct entities. The study was carried out by EM Philips 400 T. The results demonstrate that nodules showed epithelial changes in the form of gaping of the intercellular junctions and absence of the basal lamina in parts. These changes are less apparent in polyps, whereas the stromal changes are more pronounced and varied. The significance of these results and their interpretation are discussed.