Biomedical subjects
Publications and source records attributed to P H Dejonckere.
Communication disorders represent a major and growing problem worldwide. In Europe, the specialty of phoniatrics has developed partly in response to this important issue. This article reviews training and workforce issues in phoniatrics and raises key questions and issues that need resolution in the future.
Substitution voicing cannot be evaluated accurately by the GRBAS perceptual rating scale, and there is a need for a valuable alternative. Therefore, we developed and tried out a perceptual rating scale, consisting of five new parameters: impression, intelligibility, noise, fluency and voicing, each to be scored between 0 (very bad score) to 10 (very good score for a substitution voice). In analogy to the GRBAS scale, they are then converted to deviance scores ranging from 0 (similar to good substitution voicing) to 3 (very deviant from good substitution voicing). Inter-individual agreement measured in a set of 24 semi-professional jury members seemed to be moderate for all parameters. Mean figures of 0.52, 0.51, 0.46, 0.53 and 0.46 are obtained for the parameters impression, intelligibility, noise, fluency and voicing, respectively. Because a high correlation exists between the first two parameters (0.917) and relying on the correlation figures between the two "I"s and the other parameters (correlation values for "impression" vary from 0.79-0.86; values for "intelligibility" range from 0.74-0.83), we suggest to discard the parameter impression, which turns the actual IINFVo scale into INFVo. The proposed (I)INFVo perceptual rating scale seems promising for the assessment of substitution voicing. Eventual improvements and practical proposals are discussed.
Otitis media with effusion (OME), a form of inflammatory middle ear disease, is a common reason for young children to visit their family doctor and to have surgery. Tubal dysfunction plays a major role in the pathogenesis. In case of persistent OME, there seems to be a logical rationale for a favourable effect on the tubal dysfunction of a functional active motoric approach combined with behavioral changes (hygiene), and as a consequence for a therapeutic effect on the middle ear disease. The basic principles of this functional treatment are: active ventilation of the middle ear, correction of immature and undesirable deviant mouth habits, increasing swallowing frequency, activating jaw and palate movements, and encouraging the use of chewing gum. The bases for this functional therapy are critically analysed, and it may be concluded that all of these principles rely upon evidence based physiological mechanisms. However, the limited available clinical data from the literature are reviewed, and appear as methodologically weak. The results of an own prospective randomized pilot study comparing functional treatment with watchful waiting may be considered encouraging, since a borderline significance level was reached with a small amount of subjects.
INTRODUCTION: A multidimensional protocol has been established by the ELS in order to reach better agreement and standardisation for functional assessment of pathologic voices. In order to evaluate the validity, practicability and applicability of this protocol the experiences of 6 european voice centres have been analysed in a retrospective study. MATERIAL AND METHODS: The ELS protocol comprises 5 dimensions: perceptual voice evaluation, videostroboscopy, acoustics, aerodynamics and subjective rating by the patient. Results obtained in 94 patients with benign voice disorders were evaluated retrospectively in a multicenter study. RESULTS: According to our results, the validity, practicability and applicability of the ELS protocol was largely satisfactory. This was true for all "common" voice disorders, but not for extreme voice alterations (e. g. spasmodic dysphonia, aphonia, substitution voices). The 5 dimension proofed to be not redundant and were able to selectively differentiate pre- post changes among various etiologies of voice disorders, various types of treatment and genders.
The effect of voice therapy in a group of chronically dysphonic patients with diverse diagnoses was studied according to the normal clinical procedure. The results were evaluated by perceptual rating, acoustic analysis, and the assessment of laryngostroboscopic recordings. Although the group effects for the differences between posttherapy and pretherapy data were clearly significant, the effects of voice therapy for the individual patients were divergent. For each of the three evaluation methods, a significant improvement was found for about 40% to 50% of the patients. The diversity of the therapy outcome among the patients could not be explained by the pretherapy status nor by age, gender, or diagnosis groups. In general, the perceptual ratings and the acoustic parameters from the baseline data were clearly correlated. However, these characterizations of the voice were only moderately correlated with the visual evaluation of the vocal fold vibrations. Relations among the three evaluation tools for the changes caused by voice therapy were very weak. The low correlation among the three methods suggests that a multidimensional evaluation of the voice is necessary to give a complete picture of the therapy outcome.
The effects of voice therapy in a group of chronically dysphonic patients are determined using two quality-of-life (QOL) instruments: the Voice Handicap Index (VHI), and a simple three-item outcome scale (three visual analogue scales). Both instruments measure changes in the quality of the voice itself and in the extent of impairment resulting from the dysphonia as experienced by the patient in social and occupational settings. Statistical tests conducted on pre- and post-treatment data indicated significant improvements on both instruments for the group as a whole. At the individual level, however, the effects were diverse. For roughly 50% of the subjects, a significant improvement could be established. The positive changes as measured with the three-item scale were greater than those measured with the VHI. The results suggest that the two QOL instruments measure slightly different aspects of the subjective perception of the therapy effects. In order to obtain a general evaluation of the patient's handicap, it may suffice to ask some simple questions.
The proposal of this basic protocol is an attempt to reach better agreement and uniformity concerning the methodology for functional assessment of pathologic voices. The purpose is to allow relevant comparisons with the literature when presenting/publishing the results of voice treatment, e.g. a phonosurgical technique, or a new/improved instrument or procedure for investigating the pathological voice. Meta-analyses of the results of voice treatments are generally limited and may even be impossible owing to the major diversity in the ways functional outcomes are assessed. A multidimensional set of minimal basic measurements suitable for all "common" dysphonias is proposed. It includes five different approaches: perception (grade, roughness, breathiness), videostroboscopy (closure, regularity, mucosal wave and symmetry), acoustics (jitter, shimmer, Fo-range and softest intensity), aerodynamics (phonation quotient), and subjective rating by the patient. The protocol is elaborated on the basis of an exhaustive review of the literature, of the experience of the Committee members, and of plenary discussions within the European Laryngological Society. Instrumentation is kept to a minimum, but it is considered essential for professionals performing phonosurgery.
A study of the effect of exogenous hazardous agents or conditions on the mechanical characteristics of vocal fold mucosa should meet three methodological criteria. 1) The outer surface of the mucosa should be exposed to the agent or condition while the inner surface is exposed to a physiological environment. 2) Even slight changes in mechanical characteristics should be detected. 3) The applied strain should be within physiological ranges. To date, no such method has been described in the literature. A method meeting the listed criteria is proposed and evaluated here.
In earlier work we showed that low relative humidity (RH) of inhaled air causes acoustic voice parameters such as jitter and shimmer to deteriorate. Other authors have shown negative effects on vocal efficiency. To explain these changes in the mechanical properties of the vocal folds, the effects of changes in RH of the air passing over microdissected mucosa of sheep larynges were studied. The dissected surface of the tissue specimen just touched Ringer solution and air of varying RH was blown over the specimen. The mucosa specimen was subjected to sinusoidal oscillations of length (strain) and the resulting force (stress) was measured. The gain and phase angle between the imposed strain and resulting stress were measured, and elasticity and viscosity were calculated. Two different air conditions were tested: air with high RH (100%) vs air with low RH (0%). Viscosity and stiffness increased significantly in both ambient conditions (P < 0.01). Dry dehydrating air resulted in a stiffer and more viscous cover than humid air (P < 0.001). These changes in mechanical characteristics may contribute to the effects on voice parameters described in earlier work.
Plasticity of voice quality is defined here as the degree of improvement in deviant voice quality that can be achieved immediately or quasi-immediately by changing basic voicing conditions, posture, articulation or resonance, breathing mechanics, laryngeal position, or auditory feedback. Thirty-two adult patients with various benign organic voice pathologies, and who had a (preoperative) functional voice therapy, were scored before therapy using a weighted multidimensional Index of Voice Plasticity (IVP). The hypothesis is that IVP could be a predictor of the final outcome of functional voice therapy, and therefore a correlation with a comparable quantification of the actual results of the therapy was investigated. The IVP shows a satisfactory correlation (Spearman's rho = 0.68) with the efficacy of (preoperative) voice therapy. The IVP also significantly differs between diagnostic categories. Although its predictive value remains limited, the Index of Voice Plasticity seems helpful in decision making for indication of (presurgical) voice therapy.
Seventeen patients (4 to 24 years old; mean, 9.7 years) with mild velopharyngeal insufficiency were treated in our department during the period 1996 to 1999 with augmentation of the posterior pharyngeal wall with autologous fat. The main disorder was a congenital short palate without a cleft, in most cases revealed by adenoidectomy. Four patients had previously undergone pharyngoplasty, and 1 had already been injected in the posterior pharyngeal wall with Teflon paste. All patients had been exhaustively treated with speech therapy, and the result remained unsatisfactory. The functional outcome of the surgical procedure was quantified by acoustic nasometry. The decrease of the nasalance percentage for a standardized spoken passage was significant 1 to 3 months after the fat transplantation, and there was a slight tendency to further reduction of nasality at the late follow-up visit, more than 6 months (average, 9.4 months) after the intervention. The mean value of the nasalance score for the "normal passage" (running speech) then reached the limit of normal values. A long-term follow-up (average, 24.3 months) by telephone questionnaire confirmed the persistence of the beneficial results. Autologous fat seems an excellent alternative for Teflon in this indication. Acoustic nasometry allows a precise quantitative assessment of functional velopharyngeal surgery.
The voice laboratory is an essential tool in the voice clinic. It provides a functional diagnosis of disturbed voice production, demonstrating the deviant characteristics, limitations, and possibilities for change. As voice is multidimensional, several aspects need to be documented, quantified, and analyzed: perception, stroboscopy, aerodynamics, acoustics, self-evaluation by the patient, and in specific cases, physiologic signals, such as electroglottography, flow glottography, nasometry, and electromyography. Effectiveness and outcome studies rely on such data.
The proposal of this guideline or basic protocol is an attempt to reach better agreement and uniformity concerning the methodology for functional assessment of pathological voices. The purpose is to allow relevant comparisons with the literature when presenting/publishing the results of voice treatment, e.g. a phonosurgical technique, or a new/improved instrument or procedure for investigating the pathological voice. Meta-analyses of results of voice treatments are generally limited--and even impossible--due to the major diversity in assessing functional outcomes. A minimal, multidimensional set of basic measurements is proposed, suitable for all "common" dysphonias: it includes 5 different approaches: perception (grade, roughness, breathiness), videostroboscopy (closure, regularity, mucosal wave and symmetry), acoustics (jitter, shimmer, Fo-range and softest intensity), aerodynamics (phonation quotient), and self rating by the patient. The protocol is elaborated on the base of an exhaustive review of the literature, the experience of the Committee members, and of plenary discussions within the European Laryngological Society. Instrumentation is kept to a minimum, but considered essential for professionals performing phonosurgery.
45 patients with various kinds of organic benignant voice pathology (vocal fold nodules, polyp, Reinke's oedema, unilateral paralysis, sulcus/scar) and/or with muscle tension disorders, for which a (pre-operative) functional voice therapy was indicated, were evaluated before and after this short period of voice therapy (4-26 sessions), in order to check a basic multidimensional protocol for assessing functional results of voice treatments, developed by the Committee on Phoniatrics of the ELS. Perception: Grade, Breathiness and Roughness from the GRBAS-scale, as rated by two experienced judges (0 = normal or absent; 3 = severely deviant or present). Acoustics: Jitter % and Shimmer % as computed by the MDVP program of Kay Elemetrics on a /a:/, at comfortable loudness and pitch. Also Fo-range and softest possible intensity were registered. Videostroboscopy: Glottal closure, regularity, mucosal wave and symmetry, as rated separately on visual analog scales of 10 cm by 2 experienced laryngologists. Phonation quotient: computed by dividing the vital capacity (ml) by the maximum phonation time (s) (best value of 2 x 3 trials). Self rating by the patient: voice quality in itself and general social/occupational handicap due to the voice problem were rated on 2 visual analog scales. Results show that there is a large variation in the interindividual and interdimensional results of the voice therapy: in a same patient, one dimension may be significantly improved while another one is significantly worsened. The 5 considered dimensions may be considered as low redundant.
Cortical evoked response audiometry is adequate for approximating hearing threshold levels with frequency specificity when the psychoacoustic responses lack reliability and reproducibility (compensation claim). It is well-known that control of wakefulness is essential for the reliability of slow vertex responses (SVR). Therefore, sedative, hypnotic, and neuroleptic drugs are supposed to have possible adverse effects on the detection of SVR. In contrast, brainstem evoked responses (BER) have proved not to be significantly affected by therapeutic doses of these compounds. The purpose of our study was to assess the reliability of SVR-threshold definition in subjects taking neuroleptic, sedative, and hypnotic drugs. Fifteen subjects examined for occupational hearing loss at the Fund for Occupational Diseases in Brussels and regularly taking one or several of these drugs were compared with 27 comparable controls. In each subject the auditory thresholds were defined with both techniques: SVR (1, 2, and 3 kHz) and BER (clicks). A highly significant difference is observed between the two groups: In the group receiving drugs, the SVR threshold for 3 kHz is 12.1 dB (average) higher than the BER threshold, whereas in the group without drugs, the SVR threshold for 3 kHz is 7.77 dB (average) lower than the BER threshold. In the drug group, large interindividual differences are observed. It may be concluded that the use of neuroleptics, sedatives, and hypnotics renders the auditory threshold definition with SVR completely unreliable. In using SVR for medicolegal threshold definition, controlling the 3-kHz threshold with BER always is necessary.
To evaluate the medicolegal relevance of middle latency responses for objectively approximating frequency-specific hearing levels in subjects with occupational hearing loss, we compared the middle latency response with the cortical response in 22 reliable subjects who had noise-induced hearing loss and were submitting claims for compensation and 21 subjects who had noise-induced hearing loss but were exaggerating the level of this loss and also were submitting claims for compensation. Middle latency components of auditory evoked potentials, especially the time-saving 40-Hz response, seem efficient and reliable for evaluating the true pure-tone thresholds (1, 2, and 3 kHz). A good correlation exists between the 40-Hz response threshold and the slow vertex response (SVR) threshold (long latency). Both also show a fairly close correlation with behavioral thresholds in cooperating subjects. However, in most cases, the 40-Hz response is less sensitive (mode of difference, 10 dB) than is the SVR. As middle latency response audiometry is not actually a time-saving procedure in comparison with cortical evoked response audiometry and as it seems less sensitive than the SVR for approximating the true threshold, the use of middle latency response audiometry seems best limited to situations in which a control or a confirmation of the SVR is wanted. Further information about the sensitivity of middle latency response to drug effects and to subject wakefulness (specifically, whether the patient is more or less sleepy) is expected.
Voice problems seem to concern more than one child out of twenty, and may concern quality (hoarseness), resonance (nasality), pitch (mutation) and loudness. The main etiological categories are defined as organic (congenital/acquired), functional/habitual (especially due to voice abuse and misuse), and psychogenic (especially mutation disorders). Flexible transnasal endoscopes of small diameter (2.3 mm) are optimally suited for accurate endoscopic diagnosis, especially if combined with video-recording and stroboscopy.
OBJECTIVE: In this pilot study, the reliabilities of the perceptual ratings of four types of speech samples by six judges, with and without expertise in evaluating cleft palate speech, were studied. DESIGN: Pre- and postoperative tape recordings of 15 patients with cleft lip and palate who had undergone a superiorly based pharyngeal flap operation were selected. Five speech-language pathologists and one oral and maxillofacial surgeon perceptually rated the following variables on separate 100-mm visual analog scales: hypernasality, audible nasal emission, intelligibility, misarticulations associated with velopharyngeal insufficiency, voice quality, and the presence or absence of hyponasality. These six variables were rated in four types of speech samples: reading of three sentences, repeating after the speech pathologist of three sentences, 10 sentences containing the aforementioned material, and the same 10 sentences in paired comparison. All speech samples were rerated after 3 months by the same judges. RESULTS: Judges differed largely in the range they used in their rating. Intrajudge reliability of .56 to .78 was found for ratings of hypernasality. No significant differences in intrajudge reliability were found for the ratings with the different types of speech samples. The intrajudge reliability of a judge with expertise was not necessarily higher than of a judge without this expertise. CONCLUSIONS: The improvement in speech is most reliably assessed with speech samples in paired comparison. A speech-language pathologist with expertise in evaluating cleft palate speech does not guarantee a high intrajudge reliability of the rating.