M. Nasser Kotby

Ain Shams University, Al Qāhirah, Al Qāhirah, Egypt

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Publications (37)25.7 Total impact

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    ABSTRACT: 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.
    No preview · Article · May 2012 · Archives of Oto-Rhino-Laryngology
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    ABSTRACT: Although recognized as a valuable diagnostic tool for more than 60 years, many laryngologists do not routinely use laryngeal electromyography (LEMG). This may be due to a persisting lack of agreement on methodology, interpretation, validity, and clinical application of LEMG. To achieve consensus in these fields, a laryngeal electromyography working group of European neurolaryngologic experts was formed in order to (1) evaluate guidelines for LEMG performance and (2) identify issues requiring further clarification. To obtain an overview of existing knowledge and research, English-language literature about LEMG was identified using Medline. Additionally, cited works not detected in the initial search were screened. Evidence-based recommendations for the performance and interpretation of LEMG and also for electrostimulation for functional evaluation were considered, as well as published reports based on expert opinion and single-institution retrospective case series. To assess the data obtained by this literature evaluation, the working group met five times and performed LEMG together on more than 20 patients. Subsequently, the results were presented and discussed at the 8th Congress of the European Laryngological Society in Vienna, Austria, September 1-4, 2010, and consensus was achieved in the following areas: (1) minimum requirements for the technical equipment required to perform and record LEMG; (2) best practical implementation of LEMG; (3) criteria for interpreting LEMG. Based on this consensus, prospective trials are planned to improve the quality of evidence guiding the proceedings of practitioners.
    Full-text · Article · May 2012 · Archives of Oto-Rhino-Laryngology
  • M Nasser Kotby · Hassan Wahba · Amr Mabrouk
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    ABSTRACT: Muwaffaq-al-Deen abu-al-Abbas Ahmad ibn Abi Ussaibea (1203-1270) was born in Damascus. He started his brilliant career in his birth place then moved to Cairo where he worked and excelled for the rest of his life. His learning was intensified by the scholarly contacts of the intellectual leaders of the day. In this study we review The Index of Physicians-Oyoun al-Anbaa Fi Tabaqat al-Attiba--(Sources of Information in the Classes of Physicians) of ibn Abi Ussaibea.The biographies in this book do not just cover physicians only but also the learned people of his day whose knowledge and expertise covered medicine, astronomy, mathematics, philosophy, and botany. For this reason the book of ibn Abi Ussaibea represents an indispensable source of the scientific and philosophical achievements of the Arabic/Islamic civilization.
    No preview · Article · Dec 2010
  • M. Nasser Kotby · M Saleh · M Hegazi · N Gamal · M. Abdel Salam · A Nabil · S Fahmi
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    ABSTRACT: 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. 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. 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. 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. 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.
    No preview · Article · Oct 2010 · Folia Phoniatrica et Logopaedica
  • M. Nasser Kotby · L K Haugen
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    ABSTRACT: Muscle and nerve stimulation experiments have been carried out on a series of 12 human larynges with malignant disease of essentially unilateral involvement. In the course of total laryngectomy tests were applied to several internal and external laryngeal muscles as well as the recurrent and superior laryngeal nerves on both sides. Muscle stimulation experiments were carried out also on the recently excised larynx. The effects were studied on the relatively unaffected side, where vocal fold mobility was apparently free. Stimulation of the sternothyroid muscle constantly led to dilatation of the laryngeal inlet and widening of the glottis. Abduction of the vocal fold occurred only in 50% of the cases (3 out of 6) on stimulation of the posterior crico-arytenoid muscle. Various explanations of these phenomena are discussed. Stimulation of the recurrent laryngeal nerve produced adduction of the vocal fold to the paramedian plane. In two experiments out of seven, however, stimulation of the recurrent laryngeal nerve led to abduction of the vocal fold. In no instance could repeated stimulation of this nerve produce two different responses, abduction and adduction, in the same experiment. Evidence is presented of the existence of both sensory and motor bundles in the recurrent laryngeal nerve. Adduction of the vocal fold to an intermediate position was noticed on stimulation of the superior laryngeal nerve. This was shown to be mediated through its external branch, the effector muscle being the crico-thyroid.
    No preview · Article · Feb 2010 · Acta Oto-Laryngologica
  • M. Nasser Kotby · L K Haugen
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    ABSTRACT: Some salient problems concerning the diagnosis and prognosis of vocal fold mobility disturbances are briefly outlined. The application of laryngeal electromyography in such cases is recommended. A brief review of EMG findings in the normal and diseased neuro-muscular system is given. In the present study electromyographic investigations of the laryngeal muscles were made of 13 patients (5 males and 8 females) with ages ranging from 22 to 70 years. Their clinical diagnoses included a variety of etiological factors. The posterior crico-arytenoid, thyro-arytenoid and crico-thyroid muscles were routinely examined. A method for the performance of these tests, in the form of an initial sitting and repeated follow-up control studies, is given. The clinical versus EMG findings are analysed. The criteria of neuropathic changes in laryngeal electromyograms are described and their significance is discussed.
    No preview · Article · Feb 2010 · Acta Oto-Laryngologica
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    ABSTRACT: 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.
    Full-text · Article · Feb 2010 · Archives of Oto-Rhino-Laryngology
  • M Nasser Kotby

    No preview · Article · Feb 2010 · Archives of Oto-Rhino-Laryngology
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    Full-text · Article · Jan 2010
  • M. Nasser Kotby · Safaa El-Sady · Mona Hegazi
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    ABSTRACT: The team of the Unit of Phoniatrics and Logopedics of the Ain Shams University Clinic in Cairo, Egypt, has worked for three and half decades to spread awareness of child language disorders. This involved publications to inform the public, as well as health care professionals, about the needs of children with delayed language, through description and based on results of epidemiological surveys. Some research was aimed at acquiring basic data on the clinical profiles of children with language problems, as well as assessment and intervention for addressing these problems. The article also outlines educational programs in our unit at Ain Shams University and describes efforts to spread our model of services to other places in Egypt and neighboring countries where such services have been unavailable.
    No preview · Article · Dec 2009 · Topics in Language Disorders
  • M. Nasser Kotby · M.A. Hegazi · I Kamal · N. Gamal el Dien · J Nassar
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    ABSTRACT: 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). 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. 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. 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.
    No preview · Article · Feb 2009 · Folia Phoniatrica et Logopaedica
  • M. Nasser Kotby · S Tawfik · A Aziz · H Taha
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    ABSTRACT: 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.
    No preview · Article · Feb 2008 · Folia Phoniatrica et Logopaedica
  • M Nasser Kotby

    No preview · Article · Jul 2005 · Archiv für Klinische und Experimentelle Ohren- Nasen- und Kehlkopfheilkunde
  • M.N Kotby · M Baraka · S.R El Sady · M Ghanem · R Shoeib
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    ABSTRACT: Psychogenic background of non-organic dysphonia has been suspected for some time. The purpose of this study is to assess cases of non-organic voice disorders in order to elucidate the role of psychogenic stress in the pathogenesis of this clinical entity. To reach our goal, 100 non-organic voice disorder patients were subjected to both voice and psychiatric protocols of assessment and the results obtained were compared with the results of 50 normal individuals whom subjected to the same protocols of assessment. The results showed that there was a highly significant difference between both groups as regards the scales of psychiatric tests. Conclusion: there is evident psychogenic background for some types of non-organic voice disorders, namely, incomplete mutation, phonasthenia and non-organic aphonia. This may necessitate a combined therapy program of behavior readjustment voice therapy as well as psychiatric management for these cases to get best results and avoid relapse.
    No preview · Article · Oct 2003 · International Congress Series
  • M.N. Kotby · S.R. El Sady
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    ABSTRACT: Background: Care of the professional voice in developing countries like Egypt is not that widely prevalent, so it is expected to have a big size of the problem among the different categories. Methods: In an attempt to demonstrate the type and nature of the breakdown of the singing voice, how to evaluate and to treat this, 22 singers with variable vocal breakdown were subjected to a comprehensive protocol of voice assessment which was carried out in the Phoniatric unit, Ain Shams University. The diagnostic protocol encompassed elementary diagnostic procedures including interviews with the patients APA, clinical diagnostic aids (laryngostroboscopy and high-fidelity voice recording) and additional instrumental measures including aerodynamic and acoustic measures. Results: The presenting problem was change of voice, phonasthenia or potential resonance problem. There was minimal initial pathological profile ranging from hyperfunctional dysphonia or phonasthenic manifestations with suitable stroboscopic aerodynamic and acoustic changes to minimal vocal fold lesions as polyps nodules, early Reinke's oedema or dysplasia. A wide variety of singers were represented in this study (artistic singers “operatic, pop, ballad and oriental” and specialized singers: “Quraan reciters and priests”). Treatment modalities were mainly behavior readjustment voice therapy. Phonosurgery was resorted to some cases with an adjuvant voice therapy. Vocal breakdown improved both subjectively and objectively. Conclusion: Egypt represents a unique multicultural society with a wide variety of singers. Accent Method (AM) proved to be effective either per se or in conjunction with phonosurgery in readjusting some mechanisms of the breakdown of the vocal technique.
    No preview · Article · Oct 2003 · International Congress Series
  • Tamer Abou-Elsaad · M. Nasser Kotby
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    ABSTRACT: This prospective study is conducted in order to evaluate the efficacy of behaviour readjustment therapy (BRAT) for oro-pharyngeal dysphagia. Thirty patients with oro-pharyngeal dysphagia resulting from various etiologies are evaluated through a diagnostic protocol utilizing subjective as well as quasi-objective measures of evaluation. The initial assessment presents the baseline (pretest) data for the patient. All patients received certain items of BRAT (posture techniques, swallowing manoeuvres, etc.) to correct the most evident breakdown of their swallowing problems. The follow-up evaluations are done after 1 month (midtest) and after 2 months (posttest) to examine the efficacy of BRAT according to a specially designed scoring protocol where each subject serves as his or her own control (within-subject strategy). The scoring system included: (I) compliance of the patient to BRAT, (II) functional outcome measures (FOM), (III) effect of BRAT on biomechanical measures (BMM) of swallowing (based on video fluoroscopic assessment) and (VI) quality of life evaluation (QOL). A rating scale was developed for all the previously mentioned items and their subitems with lower rating towards normal eating and drinking. The results proved the efficacy of BRAT techniques to control the problem of penetration/aspiration of swallowed bolus and its positive significant correlation with the compliance of the patients to BRAT. The improvement in the BMM for all bolus consistencies, the FOM and QOL evaluations followed a more or less linear curve indicating the patient's gain continue smoothly throughout the therapy period and the beneficial effects of the BRAT to control the swallowing problem.
    No preview · Article · Oct 2003 · International Congress Series
  • M. N Kotby · A El-Makhzangy

    No preview · Article · Oct 2003 · International Congress Series
  • M. N Kotby · A Moussa · S. R El-Sady · A. A Nabieh
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    ABSTRACT: Stuttering is one of the controversy diseases. Thus, therapy for stuttering varies according to the therapists' belief. This study was conducted on four groups of stutterers; 30 stutterers each, with age range 15–35 years. Three groups received therapy sessions using the three different behavioral readjustment programs mainly: Coarticulation program of Stromsta, Smith Accent Method, and Van Riper's Non-Avoidance program. All patients attended individual therapy sessions, twice a week. The fourth group was a control one. All patients were assessed at the interview, after 8 weeks, and after 16 weeks.A multidimensional assessment protocol was used for assessment of all patients. It included elementary diagnostic procedures, clinical diagnostic aids, and additional instrumental diagnostic assessment.The results obtained from this study showed that there were significant improvements of the stuttering severity for most of the measurable parameters for all therapeutic groups. Although there was significant difference between all therapeutic groups and control group, there was no significant difference between the results of all therapeutic groups.
    No preview · Article · Oct 2003 · International Congress Series
  • M.N Kotby · N.A Labib · A.A Aziz
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    ABSTRACT: This study demonstrates the various socioeconomic indices in Egypt, as a developing country. The implications of such economic indices on planning and developing health services in the field of phoniatrics and communicative disorders are given and discussed. The study refers to the total resources allocated to health, followed by resources allocated to rehabilitative services to reach the final human and financial resources allocated to communicative disorders.
    No preview · Article · Oct 2003 · International Congress Series
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    ABSTRACT: 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.
    No preview · Article · Feb 1996 · Scandinavian audiology. Supplementum