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Biomedical subjects

M Ouaknine

Publications and source records attributed to M Ouaknine.

At least 19 recordsLinked to original sources
PubMed2005

[Twenty nine shoulder reconstructions after resection of the proximal humerus for neoplasm with mean 7-year follow-up].

PURPOSE OF THE STUDY: Techniques available for shoulder reconstruction after resection of a tumor of the proximal humerus include scapulohumeral arthrodesis, humerus prosthesis with or without an allograft, inverted prostheses, and massive allografts. The purpose of this study was to review clinical and radiological outcomes in a series of 29 patients (20 men and 9 women) who underwent resection-reconstruction of the proximal humerus and to establish from these cases a decision making algorithm for therapeutic indications as a function of tumor invasion. MATERIAL AND METHODS: The tumors were 20 chondrosarcomas, five osteosarcomas, two Ewing sarcomas and one malignant hemangiopericytoma. In 17 patients epiphyso-metaphyseal or epiphyso-metaphyso-diaphyseal resection was performed with preservation of the abductor muscles (type S34A or S345A according to the Musculoskeletal Tumor Society classification). For 12 patients epiphyso-metaphyseal or epiphyso-metaphyso-diaphyseal resection was performed without preservation of the abductor muscles (type S34B or S345B). Reconstruction was achieved using a centromedullary cemented nail in one patient, scapulohumeral arthrodesis in three, a massive humerus prosthesis in 15, and composite humerus prosthesis in three and an inverted prosthesis in seven. The functional score of the Musculoskeletal Tumor Society (MSTS) and standard x-rays were used to assess outcome. RESULTS: Mean follow-up was 85 months (range 16-300). The mean MSTS score was 88% for inverted prostheses, 76% for composite prostheses, 72.6% for massive prostheses, 75% for scapulohumeral arthrodeses, 67% for massive prostheses, and 80% for cemented centromendullary nail. Five patients died from their malignant disease and one from another cause. Four patients are alive but with active disease after a mean follow-up of 108 months and 19 patients (65.5%) are alive and free of locoregional recurrence or metastasis after a mean 83.5 months. We had 28 complications. Glenohumeral instability was the most frequent (11 cases). DISCUSSION: Resection of the upper portion of the humerus should be performed to achieve cancerologically satisfactory tumor resection and enable shoulder resection, if possible, with preservation of a viable and functional abductor system. The functional outcome after such reconstruction depends on the type of bony resection, but also on the sacrifice of the rotator cuff and the deltoid muscle. In light of our experience and results in the literature, we advocate, despite the small number of cases for the different reconstructions, the following decision-making algorithm after resection of the proximal humerus without joint invasion: when the resection removes the rotator cuff and the deltoid (or the axillary nerve), there are two options: scapulohumeral arthrodesis or massive humerus prosthesis for patients who do not desire a complex therapy with a long postoperative period; when the resection preserves the rotator cuff and/or the deltoid muscle, reconstruction can be achieved with a composite (inverted or not) prosthesis with suture of the cuff tendons. We prefer the inverted composite prosthesis; if the deltoid muscle can be preserved but not the rotator cuff, the composite inverted prosthesis appears to be the most logical solution, but scapulohumeral arthrodesis can be proposed in selected cases.

Adolescent↗
PubMed2005

[Normal mouth opening in the adult French population].

INTRODUCTION: Limitation of mouth opening is a frequent symptom in the pathologies of the temporomandibular joint. The aim of this study is to establish normative basis for this criterion in the French population. MATERIALS AND METHODS: Maximal mouth opening was measured by an electronic goniometric device. Measurements were taken in 228 people (110 men and 126 women) aged between 18 to 84 years, representative of the French population. RESULTS: The average mouth opening is 50.7 7 mm, but it was greater in the male population. It was also greater in tall patients and in younger patients (under 50 years). DISCUSSION: Our study is original because it is based on normal subjects and because our population sample age is the same as that of the French population. Men have a greater mouth opening than women, but this can be due to the fact that they are taller. Mouth opening is wider in young subjects, under 50, because they are younger and because they are taller. Mouth opening is wider in tall patients, whatever their sex or their age.

Adolescent↗
PubMed2005

[Increase in the abdominal respiratory movements during the sudden passage from a conversational voice to a loud voice].

UNLABELLED: The passage of the simple conversational voice to a loud voice is accompanied by an increase in the muscular tensions as well as increase in the mobilized volumes of air. OBJECTIVES: We sought to know if these additional volumes were mobilized rather by a thoracic breathing or an abdominal breathing and if this effort were accompanied by a reduction in the variability of the movements. MATERIAL AND METHOD: The study presented is a prospective experimental study undertaken on healthy subjects (10 subjects) of which we analyzed the spontaneous vocal behavior (conversation with the experimenter) in the medium of vocal spots lures (production of vowels) in a calm environment allowing a conversational voice (condition 1) and in a noisy environment obliging the subjects abruptly to use a strong voice (condition 2). Thoracic and abdominal volumes were recorded using belts provided with pressure pick-ups, while the voice was synchronized with the recordings. RESULTS: The results show a reduction in the number of rheses realized with abdominal volumes and a reduction in the abdominal volumes mobilized in condition 2, testifying to a preferential use of thoracic breathing in loud voice. They also show a reduction in the number of movements of the inspiratory type (increase in the thoracic diameter or reduction in the abdominal diameter) during the phonatory phase in condition 2, which testifies to a reduction in the variability of the strategies used by the subjects. CONCLUSION: The sudden passage to a loud voice because of the appearance of an ambient noise leads to an increase of the use of thoracic breathing, which is in agreement with the concept of voice of distress or of emergency suggested by Le Huche.

Abdominal Muscles↗
PubMed2004

[Trauma-induced tears of the quadriceps tendon: 47 cases].

PURPOSE OF THE STUDY: A torn quadriceps tendon is an exceptional finding generally observed after high-energy knee trauma in patients over 40 who present a sprain-like syndrome or after low-energy trauma in elderly subjects who experience knee instability. We reviewed a series of 47 cases of traumatic quadriceps tendon tears treated between 1976 and 1996 in order to evaluate outcome after surgical repair. MATERIAL AND METHODS: Clinical diagnosis was the rule. Forty-two patients, mean age 55 years (range 17-92) were treated for tears of one or both quadriceps tendons subsequent to low-energy trauma (40 tears) or high-energy trauma in younger subjects. The diagnosis was established early in all cases except eight (diagnosis at three weeks to one year). Surgical repair was performed in all cases except one. After surgery, the knee was either immobilized with a plaster cast or held in a removable splint to allow early mobilization. RESULTS: Average time to recovery compatible with daily life or occupational activities was four months. Recovery was not complete at this time. Long-term follow-up revealed that complete recovery with very good or good subjective results was achieved in 90% of the cases. Complete joint motion and normal quadriceps force was achieved in 80% of the cases. Patients who started rehabilitation exercises early generally achieved less satisfactory results although no significant correlation was identified with objective clinical variables. DISCUSSION: Quadriceps tendon tear is a clinical diagnosis which does not require complementary exploration for confirmation. Plain x-rays may be useful to identify associated bony lesions and specific signs of tendon tears. Early surgical repair followed by complete immobilization appears to be preferable for functional recovery allowing better recovery of muscle force without compromising flexion.

Activities of Daily Living↗
PubMed2004

[Improvement in postural orientation and stability after stereotactic gamma irradiation of acoustic neurinomas].

Non-surgical stereotactic gamma ionizing irradiation was developed in order to produce a lethal effect on unilateral acoustic neurinomas (vestibular schvannomas). We present a study of postural vestibular dependent performances in 218 patients before and after curative irradiation. Subjects were asked to stand at ease on a static dynamometric foot-plate, gazing at a fixed point in front of them (EO condition) or to stand eyes closed (EC condition). Statokinesigrams were registered during two consecutive sessions of 51.2 sec, under EO and EC conditions. These sessions were first managed the days before (d-1), and after (d+1) irradiation; others were performed later (d+1 to 5 Years; n=37). Center of pressure (CofP) mediolateral (X) and sagittal (Y) positions were quantified every 100 msec. Mean Xm session value (with SD) was taken as a personal parameter for left or right body inclination. Area S for 90% of the XY successive placements of the CofP observed during a session was taken as an index for 2D postural way. Before irradiation the overall average of the 218 personal Xm mean values demonstrated a statistically significant body inclination toward the affected side, however under EC condition only. The day after irradiation, a significant reduction of the overall mean value of body inclination was observed. Paired Xm statistics of confirmed this trend toward usual symmetry. The day after stereo-irradiation, averaging areas S of ellipses indicated a shift of instability toward normality. For the two parameters, the pseudo-Romberg ratios (performance EC/performance EO) indicated that a special visual contribution to balance control is present in patients with a neurinoma tumor (here I and II grades). The relative importance of this visual support declined shortly after ionizing treatment. Because the radiation is neither noxious nor excitatory we think such a rapid recovery is due to some recovery of vestibular nerve afferent conduction, and a rapid neural reprogramming of the balance control. These attractive results call for deeper investigations of both vestibular and auditory functions.

Cohort Studies↗
PubMed2004

[Study of the supra-glottic pressure during partial constriction of the vocal tract].

OBJECTIVES: Phonation in a small plastic tube 22 cm length and 5 mms diameter (basic exercise of the method of Dr Amy de la Brèteque), is current practice in vocal rehabilitation in France. This work aims to show the effects of this method on the glottic vibration. The hypothesis was that at the time of phonation in the tube with a strong flow as recommended in the method, the vocal cords vibrate without contact. This limits the mechanical trauma at this level. MATERIAL AND METHODS: We have analyzed the sound production in a tube in 11 trained and not trained subjects. We simultaneously collected the intra-oral air pressure and the vocal signal which was subjected to a spectral analysis. RESULTS: Spectral analysis confirmed that the signal was produced correctly i.e. with a strong flow and without interruption of the sound less rich in harmonics. We interpreted these results in the light of our preceding works on the glottic vibration and we show that this vocal production was of the sinusoidal type; this implies the absence of physical contact between the vocal cords, which validates our hypothesis. CONCLUSION: Further works are necessary to better understand the physical relations between the supra-glottic aerodynamic phenomena and the vibratory functioning of the vocal cords and also to analyze the therapeutic potential ofthe method within speech therapy rehabilitation.

Adult↗
PubMed2002

[Non-linear model of glottic vibration. Potential clinical implications].

Glottic vibration is governed by a certain number of physical laws which in general correspond, as far as myo-elastic theory is concerned, with the laws of passive vibration of an elastic body under the influence of the expired air. Some of these laws are non-linear, especially those that deal with the exchange of energy between the expired air and the vocal folds. This non-linearity is specially important when it comes to the key concepts of the phonatory threshold and the passive synchronisation of the vocal cords. Based on their experimental work, which has been presented previously, the authors propose a mixed model, which is both linear and non-linear, like the oscillators of Van der Pool. This model is known as Slip-Stick.

Glottis↗
PubMed2002

[Comparative study of respiratory mechanisms between professional lyrical singers and beginners].

The apprenticeship for classical singing requires years of training due to its complexity. This training is directed at the different levels of the vocal apparatus: the source of energy or air flow (lungs), the vibrator (vocal cords) and the resonators (bucco-pharyngeal cavity). For this study we have concentrated on the first level, that is, respiration. When a greater demand of vocal activity is required respiration becomes more sustained and more complex; this is when difficulties may be observed. Singers overcome these difficulties through different strategies according to their level of vocal training. Our study compared respiratory strategies used by professional singers and singing students (first year conservatoire students) during singing tasks; none of the subjects had any history of vocal pathology. Electromyographic analysis of muscle activity was registered for the rectus abdominals muscle, external oblique muscle and transverse muscle with surface electrodes. Kinetic analysis was used to measure thoracic cage displacement: pressure sensitive belts were placed around the pubis, the epigastric region and thorax. The subjects were asked to perform two vocal tasks: vocalization of a sustained "i" and singing of an extract of a vaccaï. Results were compared between the 7 professional singers and the 6 singing students. They allowed us to confirm the existence of distinct respiratory strategies according to the level of vocal training, as described in literature. Professional singers inhibited the activity of their rectus abdominals muscles during singing and used mostly their external oblique and transverse muscles, thus, sustaining an expanded ribcage and a longer expiratory breath. Singing students, on the other hand, worked intensively all the abdominal muscles leading to a collapse of the ribcage. Management of air was more difficult and breath was shorter. Future studies will consider a larger population sample in order to define quantitative parameters that might allow a significant differentiation of respiratory strategies between professional singers and singing students.

Adult↗
PubMed2002

Phonatory threshold pressure in a healthy population before and after aerosol treatment, a preliminary study.

The viscosity of the surface mucus of the vocal cords is one of the important elements for good laryngeal functioning. It has been demonstrated that inhalation of hydrated air increases the phonatory threshold pressure by decreasing viscosity of the mucus (1) leading to a more regular vibration that can be appreciated by jitter (2). In an attempt to correlate the concepts of tissue viscosity and surface mucus considering the theoretical model of vibration we measured the phonatory threshold pressure in 6 healthy female subjects before and after aerosol treatment. We were able to demonstrate that the pressure threshold is lower (3.15 hPa) after aerosol treatment than before (3.79 hPa) and this was statistically significant (p: 0.041). The discussion is based on this decrease of mucus viscosity applied to the physiological concepts necessary to understand glottic vibration.

Adult↗
PubMed2001

Objective voice analysis for dysphonic patients: a multiparametric protocol including acoustic and aerodynamic measurements.

The purpose was to determine the clinical value of a multiparametric objective voice evaluation protocol including acoustic and aerodynamic parameters measured mainly on a sustained /a/. This was done by comparison with perceptual analysis of continuous speech by a jury composed of 6 experienced listeners. Voice samples (continuous speech) from 63 male patients with dysphonia and 21 control subjects with normal voices were recorded and assesed by a jury of listeners. The jury was instructed to classify voice samples according to the G (overall dysphonia) component of the GRBAS score on a 4-point scale ranging from 0 for normal to 3 for severe dysphonia. Objective parameters were recorded on an EVA workstation. As usual with this type of system, parameters were measured mainly on a sustained /a/. Measured parameters included fundamental frequency (F0), intensity, jitter, shimmer, signal-to-noise ratio, Lyapunov coefficient (LC), oral airflow (OAF), maximum phonatory time (MPT), and vocal range (range). Estimated subglottic pressure (ESGP) was determined on a series of /pa/. Discriminant analysis was performed to detect correlation between jury classification and combinations of parameters. Results showed that a nonlinear combination of only six parameters (range, LC, ESGP, MPT, signal-to-noise ratio, and F0) allowed 86% concordance with jury classification. Discussion deals with the relative importance of the different objective parameters for discriminant analysis. Special emphasis is placed on two measurements rarely made in routine clinical workup, i.e., estimated subglottic pressure and Lyapunov coefficient.

Adult↗
PubMed2000

Orientation of the body response to galvanic stimulation as a function of the inter-vestibular imbalance.

We proposed to study and quantify the anteroposterior component, on top of the lateral one, of the body sway induced by different configurations of galvanic vestibular stimulation (GVS) in order to advance the understanding of the orientation of the response. Four stimulation configurations were used in two separate experiments: monaural, binaural, and opposite double monaural in the first experiment (11 subjects); monaural and double monaural in the second (13 subjects). The postural response of the subjects, standing with their eyes closed, to the stimulus (0.6 mA, 4 s) was assessed by measuring the displacement of the center of pressure (CoP) using a force platform. As usual, binaural GVS induced a strictly lateral deviation of the center of pressure. The opposite double monaural condition induced a similar lateral sway to that obtained in the binaural mode, although with a very different stimulation configuration. Monaural GVS induced an oblique, stereotyped deviation in each subject. The anteroposterior component comprised a forward deviation when the anode was on the forehead and a backward deviation when the anode was on the mastoid. The lateral component, directed towards the anode as in the binaural design, was twice as large in the binaural than in the monaural mode. The second experiment showed that double monaural stimulation elicited an anteroposterior deviation (backwards when the anode was on the mastoids and forwards when it was on the forehead) that was equivalent to the addition of two complementary monaural configurations. The present results show that monaural stimulation activates one side of the vestibular apparatus and induces reproducible, stereotyped deviations of the CoP in both the anteroposterior and lateral plane. Secondly, binaural GVS appears to result from the addition of two complementary monaural stimulations. Lateral components of the response to each stimulation, being in the same direction, are summed, whilst anteroposterior components, being in opposite directions, cancel each other out. The opposite happens when both labyrinths are polarized in the same way, as in the double monaural configuration. We suggest that the orientation of the response to GVS is a function of the imbalance between right and left vestibular polarization, rather than a function of the actual position of the electrodes.

Electric Stimulation↗
PubMed2000

[Primary leiomyosarcoma of bone. Report of 5 anatomo-clinical cases and review of the literature].

INTRODUCTION: Leiomyosarcoma is a malignant smooth muscle tumor occurring most frequently in uterus or soft tissues and more rarely in bone. MATERIALS AND METHODS: We report the clinicopathologic, immunohistochemical and ultrastructural findings of five cases of primary leiomyosarcoma of bone treated in our Department between 1991 and 1994. The pertinent medical literature is discussed. RESULTS: The tumors were located respectively in the distal tibia (n=2), the distal femur, the sternum and the ilium (n=1). Four lesions were high-grade and one low-grade. All patients (3 women and 2 men) underwent wide surgical resection associated with polychemotherapy in four cases. Two patients died of metastatic disease, two had local recurrence and one is alive with no evidence of disease at the last follow-up. DISCUSSION: Excluding cases which involve the facial skeleton, there are to our knowledge 95 cases of primary leiomyosarcoma of bone reported in the literature. This tumor arises more commonly in adults (mean age: 49 years) with an equal gender distribution and involves predominantly the long bones near the knee. In the majority of cases, plain X-rays exhibit an osteolytic lesion with cortical penetration and indistinct margins. The diagnosis is based on microscopic features demonstrating fusiform tumor cells arranged in interwoven bundles, and the immunohistochemical results of widespread cytoplasmic positivity for smooth muscle actin. The best pronostic parameter is the histologic grade correlated with both the recurrence and metastatic rates as well as the survival rate. Surgery constitutes the main treatment since chemotherapy or radiotherapy did not provide an improved prognosis over a wide resection.

Adult↗
PubMed2000

[Sacral chordoma: retrospective review of 11 surgically treated cases].

PURPOSE OF THE STUDY: Chordoma is a malignant neoplasm believed to arise from notochord remnants. It accounts for approximately 3 to 4 p. 100 of primary bone tumors and is localized along the axial skeleton, 50 p. 100 being sacrococcygeal. Clinical, radiographical and histological findings have been well established since the first description by Ribbert in 1894. Sacral chordomas are however difficult to manage and remain a challenge for surgeons and radiotherapists alike. The purpose of this study was to evaluate the long-term results of surgical treatment and patterns of failure in patients treated for chordoma of the sacrum in our department. MATERIALS AND METHODS: This retrospective study included 11 cases of sacral chordomas treated from 1973 to 1998. Patient age ranged from 36 to 77 years (mean 59 years). Six patients were female and five male. The initial treatment was surgery in all cases including intralesional removal in two cases, marginal resection in seven and complete en bloc resection in two. RESULTS: Median follow-up was 6 years (1 month to 14 years). Tumoral recurrences were observed in nine cases 5 months to 8 years after treatment. In two cases, recurrence was observed 8 years after radical sacrectomy. Treatment of recurrences was partial surgical removal with radiotherapy (40 to 70 Grays). Three patients developed metastases in lungs, liver and bone, respectively. Seven patients died, two from metastatic disease. The 5-year overall survival was 64 p. 100 but only 18 p. 100 of the patients survived 10 years. Average disease-free survival was 18 p. 100 at 5 years and 0 p. 100 at 10 years. DISCUSSION: Chordoma is a slow-growing tumor allowing survival for several years despite recurrent disease. However, only 10 to 20 p. 100 of the patients survive free of disease at 5 years. Recurrences are frequent (45 to 80 p. 100) and often multiple. Chordoma inevitably recurs and eventually leads to death after intralesional removal or marginal resection. Radical surgery should be attempted whenever technically feasible. When performed early, particularly for smaller lesions, it offers the best chance for cure. However, tumoral recurrence can occur postoperatively despite a macroscopically complete resection. Because radiation therapy seems to be more successful in controlling microscopic disease, it should be considered as a pre- or postoperative adjuvant to a macroscopically complete resection.

Adult↗
PubMed2000

[Visualization of the vibratory movements of the vocal cords under asymmetrical conditions].

In this study, we present a new system for measuring the vibration signal of the larynx which allows the vibration of each vocal cord in an excised larynx to be studied using a method of distant optical measurement. The set-up consisted of an insufflator and a device for immobilising the larynx, together with microprobes capable of creating mechanical pressure at the laryngeal ventricles. The whole system was computer-controlled. The measurements were carried out under normal and asymmetrical conditions on seven excised pig larynges. Measurement of the individual vibration of each vocal cord showed that the transient period of commencement of vibration (vocal onset) is influenced to a significant extent by the degree of asymmetry. Under conditions of extreme asymmetry, movement of the cords appeared to be aberrant, but not random because of the coupling mechanisms which cause "anchoring" of the two cords during the phase of closure. Thus one cord may vibrate at twice the frequency of the other. The method described has given us a better understanding of the mechanism of laryngeal vibration, and one which is in conflict with the theoretical harmonic model in many details.

Animals↗
PubMed2000

[Clinical significance of calculating the coefficients of Lyapunov in the objective assessment of dysphonia].

Measurement of the vibration instability by means of jitter in cases of dysphonia fails to take into account certain features of the vocal signal, such as modulation or bitonatily. These abnormalities appear in jitter measurements as instability, without allowing any differentiation from random instability (to give 'true' instability). The authors suggest the use of the coefficient of Lyapunov, a measurement which is used for nonlinear dynamics. The vocal product of 179 normal and dysphonic subjects has been analysed. The coefficient of Lyapunov and the jitter were measured during the stable period of a sustained 'a' vowel. For the coefficient of Lyapunov, the authors used the algorythm which has been published previously [Giovanni et al, J. Voice 1999;13:341-354]. The measurements were compared with the perceptive analysis of the reading voice by a panel, and divided into four grade (G0 to G3). The coefficient of Lyapunov appeared to be more relevant than the jitter in distinguishing the various perceived grades. Precise recognition of the grade was obtained in 46% using the coefficient of Lyapunov as against only 36% using jitter. The addition of this new index to the existing puriparametric methods of voice analysis seems to be promising.

Acoustics↗
PubMed2000

[Forcing the voice and variance of speed: correlation between the speed of displacement of the center of gravity and the work of the postural muscles].

Using stabilometry, our experimental protocol was designed to demonstrate a quantitative parameter of posture to study forcing of the voice. Analysis of the graphs has shown a perfect correlation between increases in variance of the speed of displacement of the centre of gravity and the increase in the electrical signal from the postural muscles, which is evidence their activation during forcing of the voice. As well as the clinical applications of this protocol, it seems necessary to undertake other studies such cinematography recording of respiration.

Adult↗