[Dysarthria across Parkinson's disease progression. Natural history of its components: dysphonia, dysprosody and dysarthria]. / La dysarthrie au cours de la maladie de Parkinson. Histoire naturelle de ses composantes: dysphonie, dysprosodie et dysarthrie.

Dysarthria refers to a collective name for a group of neurologic motor speech disorders, resulting from central and/or peripheral nervous system abnormalities. Speech alteration in Parkinson's disease, so-called hypokinetic dysarthria, presents with prosodic insufficiency, related to a monotony of pitch and intensity, a reduction of accentuation, variable speech rate and possible phoneme imprecision. In most cases, voice is harsh and breathy. This symptom can affect both voice and speech quality, as well as prosody and intelligibility. As a consequence, many patients complain about speech impairments, which affect their communication in daily living activities. Perceptual and instrumental assessments require different and numerous investigation methods, which use may help to further understand the specific dysarthria pathophysiology. This is of importance in order to adjust treatments for dysarthria; as a matter of fact, dopa-therapy, functional neurosurgery or even behavioural speech therapy have variable effects on voice and speech quality in Parkinson's disease.

[Measurement of intra-oral pressure as a contributor for the understanding of pneumophonic coordination impairment in Parkinsonian dysarthria]. / Contribution de la mesure de la pression intra-orale pour la compréhension des troubles de la coordination pneumophonique dans la dysarthrie parkinsonienne.

INTRODUCTION: Parkinsonian dysarthria can alter oral communication of the patients in the long-term. Subthalamic nucleus (STN) stimulation represents an interesting therapeutic option, although it does not seem to improve axial signs, of which dysarthric speech. The objective of our study was to contribute to the evaluation of STN stimulation effects on speech impairment and in particular on pneumophonic coordination: this latter parameter can be assessed indirectly by evaluating the temporal progression of the intraoral pressure (IOP) during the expiratory phase; thus, IOP represents the transient expression of subglottal pressure (SGP). PATIENTS AND METHOD: Using a dedicated system (EVA2), 20 parkinsonian patients were recorded in ON and OFF STN stimulation conditions in order to evaluate IOP on three measurement points (2nd, 4th and 6th consonants P) during realization of the sentence "Papa ne m'a pas parlé de beau-papa" ("Daddy did not speak to me about daddy-in-law") which corresponds to a breath group. Eleven control subjects were recorded in parallel in order to define reference measurements. RESULTS: STN stimulation improved significantly IOP at the level of the initial measurement points (2nd P and 4th P), with an effect of convergence at the level of the third point (6th P) where the difference between OFF and ON STIM conditions was not significant any more. In addition, the performance of the patients ON STIM remained much lower than that of the control subjects. CONCLUSION: Our results raise the significant concept that IOP measurement can be regarded as a relevant indicator for dysarthria in Parkinson's disease. They also show that the improvement of pneumophonic coordination by STN stimulation is restricted to the initial period of the expiratory phase, confirming again the mitigated and controversial effect of STN stimulation on axial signs.

Laryngeal pathology detection by means of class-specific neural maps.

Most of the existing systems and methods for laryngeal pathology detection are characterized by a classification error. One of the basic problems is the approximation and estimation of the probability density functions of the given classes. In order to increase the accuracy of laryngeal pathology detection and to eliminate the most dangerous error--classification of a patient with laryngeal disease as a normal speaker--here an approach based on modeling of the probability density functions (pdf's) of the input vectors of the normal and pathological speakers by means of two prototype distribution maps (PDM), respectively, is proposed. The pdf of the input vectors of an unknown normal or pathological speaker is also modeled by such a prototype distribution neural map--PDM(X)--and the pathology detection is done by means of a ratio of specific similarities rather than by a direct comparison of some type of distance/similarity with a threshold. The experiments show an increased classification accuracy and that the proposed method can be used for screening the laryngeal diseases. The method is applied in a consulting system for clinical practice.

Non linear behavior of vocal fold vibration in an experimental model of asymmetric larynx: role of coupling between the two folds.

One of the main factors involved in the laryngeal dynamic's non-linearity is the coupling between the two vocal folds. Evaluation of the different coupling elements requires various investigations. The present work evaluate the non-linearity effects in clinical situations such as unilateral laryngeal paralysis using Lyapunov's coefficients. It also demonstrate the coupling effects on excised larynx made experimentally asymmetrical, using a specially designed device to measure vibrations from each vocal fold (opto-reflectometer).

[Preliminary study of acoustic and aerodynamic parameters after Tucker frontal anterior laryngectomy]. / Etude préliminaires des paramètres acoustiques et aérodynamiques après laryngectomie frontale antérieure de Tucker.

Currently, not objective method has been demonstrated to be reliable for the evaluation of vocal handicap after partial laryngectomy. Such a tool would allow objective assessment of the post-operative voice and its clinical course as well as a comparison of different surgical techniques in terms of voice quality. We used a EVA device to measure simultaneously acoustic and aerodynamic parameters. We included 23 normal subjects and 34 patients who had undergone a Tucker laryngectomy. All subjects were males. At sustained voice production, acoustic measures of vibration stability (jitter, coefficient of variation in the fundamental frequency, shimmer, coefficient of variation in intensity) and air leak from the glottis (buccal air flow over intensity). The quality of voice in operated patients was judged by a jury of listeners who assigned a global score to voice quality. Results were analyzed to verify the correlation between objective measurements and the jury's score, taken as the reference measurement. The pertinence of the objective measurements was demonstrated for the stability of the frequency and the glottal air leak. Multiple regression analysis demonstrated that total variance of the objective measurements accounted for 84.7% of the scores provided by the jury (R2 = 0.847, p < 0.0001). These satisfactory results emphasize the interest of multiparametric analysis including aerodynamic measurements. These preliminary results led to the hypothesis that objective and subjective measurements could be useful in techniques aimed at improving voice quality (temporal organization of vibratory instability, work on intralaryngeal pressures).

Objective evaluation of dysphonia: preliminary results of a device allowing simultaneous acoustic and aerodynamic measurements.

Voice quality analysis was performed in 88 normal speakers and 157 dysphonic speakers using a device that allows simultaneous study of acoustic and aerodynamic parameters during pronunciation of a sustained /a/. We compared the results with those of voice quality grading by a jury. The Mann-Whitney test showed significant differences between the grades of dysphonia for all the parameters chosen. Comparison of results (using discriminant factorial analysis) with perceptual evaluation by a jury showed concordance in 66.1%. Based on these preliminary results, the authors conclude that their protocol overlooks some relevant voice parameters like middle-term variations. Further study will be undertaken to take into account this type of variations.

[Objective vocal evaluation of dysphonia by simultaneous measurement of acoustic and aerodynamic parameters with the EVA device]. / Evaluation vocale objective des dysphonies par la mesure simultanée de paramètres acoustiques et aérodynamiques à l'aide de l'appareillage EVA.

Authors present the analysis of the voice in 88 normal subjects and 159 dysphonic patients by simultaneously measurements of Jitter (acoustical short-term indicator of aperiodicity) and "Glottal Leakage" (aerodynamic parameter calculated by the ratio of Oral Airflow and Intensity). All the measurements were performed, with EVA apparatus, on the most stable part of a steady-state vowel /a/. The reference method was the rating by a jury along a global perceptual scale. Statistical tests confirm that Jitter and "Glottal Leakage" are relevant to evaluate the quality of the voice. Discriminant analysis allows to find out a fairly-good rate of discrimination of 63.1% (Randomly rating would have been 25%) The authors conclude on the interest of such a protocol and present suggestions to improve it by taking in count phénomena during the vocal attack and middle-term variations.

[Multiparameter analysis of dysphonia using the equipment Physiologia]. / Analyse multiparamétrique des dysphonies par l'appareillage Physiologia.

The purpose of the multiparametric analysis of the vocal phenomenon is to evidence the instability of the signal in amplitude and in frequency, together with the aerodynamic phenomena related to the glottic air leakage. Statistical analysis has made it possible to establish a correlation between the data of the apparatus, as from 9 variables, and the clinical classification. The main diagnostic categories are relatively close, evidencing the various biomechanical anomalies of the laryngeal vibrator. A certain number of issues remain to be addressed: the physiopathology of the vibrator, the choice of the phonetic sample, and the different methods of instrumental analysis.

[A multiparameter method of computer-assisted objective vocal evaluation]. / Une méthode multiparamétrique d'évaluation vocale objective assistée par ordinateur.

The aim of this study is to validate an aid for the evaluation of dysphonia with objective measurements. We recorded exhaled airflow, fundamental frequency and sound level pressure, for a sustained vowel "a", with 51 dysphonic subjects and 15 normal subjects. The following measurements are made on these three parameters: mean value, standard deviation and coefficient of variation. The exhaled airflow volume was also computed for a duration of 2 seconds. A principal components analysis of the measurements indicated that it is possible to recognise the classes of vocal evaluation and vocal pathology. These findings reinforce on objective aid for the vocal evaluation of dysphonia.

[How to evaluate velar insufficiency?]. / Comment évaluer une insuffisance vélaire?

The evaluation of velar insufficiency is absolutely necessary in order to assess the results of surgery of the labial palatal cleft. In addition to the clinical examination which remains indispensable, the aerophonometer, applicable to adults and children as from the age of 3, enables simultaneous measurement of the flow of buccal air, the flow of nasal air, and the buccal phonogram. The comparison of the lines, the relation of the nasal air and buccal air flows, upon the emission of two standard sentences with and without nasal components, enables an objective assessment of velar functioning.