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Biomedical subjects

A Morgon

Publications and source records attributed to A Morgon.

At least 55 records · Page 3Linked to original sources
PubMed1994

Is the test of medial efferent system function a relevant investigation in tinnitus?

The present results are drawn from preliminary observations made in 28 patients suffering from unilateral, permanent, non-pulsatile tinnitus, who were systematically submitted to an investigation of their otoacoustic emissions in both ears. Spontaneous otoemissions (SOAE) were carefully looked for, before recording of transient evoked otoemissions (TEOAE). The effectiveness of the medial olivo-cochlear efferent system (MOC) was also tested. The comparison between TEOAE input/output curves obtained with and without contralateral stimulation allowed a global assessment of the functioning of MOC. Additional information relating to the MOC functioning at the precise frequency of tinnitus and/or around it, was available from the comparison of analogous curves obtained using distortion product otoacoustic emissions (DPOAE) instead of TEOAEs. The results show that: (1) when the amplitude of otoacoustic emissions differs between the two ears, the tinnitus is generally lateralized on the side where amplitude was the lowest, which seems to be related to a greater hearing loss; (2) no general law concerning tinnitus can be drawn from the global testing of MOC functioning; the only result is that the slope of TEOAE input/output function appears as a deciding factor for efficiency of MOC, the least efficiency almost always occurring on the side where the slope is greater, and (3) even in the case of proved global effectiveness of MOC activation, there is, at least in the vicinity and in at least one ear, a part of the cochlea where its functioning is altered. A better comprehension of the mechanisms underlying this symptom will probably come from exhaustive exploration of individual cases rather than a rougher investigation of large samples in which different aetiologies are likely to be mixed.

Adult↗
PubMed1994

[Efficacy and tolerance of cefotiam hexetil in the super-infected chronic sinusitis. A randomized, double-blind study in comparison with cefixime].

Efficacy and safety of a new oral third generation Cephalosporin, Cefotiam Hexetil (CTM) 200 mg bid were compared with those of Cefixime (CX) 200 mg bid over 10 day duration of treatment. One hundred and twenty two ambulatory adults suffering from chronic sinusitis were randomized by ENT specialists in this multicentre prospective double blind, doubled dummy study. Sinusitis diagnosis evocated in front of fascial pain, purulent nasal discharge and/or obstruction was confirmed with sinus X-ray. Use of antibiotics or corticosteroids concomitantly or 15 days prior inclusion represented one of the major exclusion criterion. One hundred and seventy one patients were evaluated for efficacy analysis (62 and 59 respectively in CTM and CX groups). Regarding demographic data, clinical and radiological signs, the two populations were comparable at inclusion excepted for sex and weight (female: 73% in CTM group versus 47% in CX group). The overall clinical success rate at the end of treatment (cure+improvement) was not significantly different between the two groups (CTM: 82% versus CX: 80%). The incidence of adverse events was less frequent in the CTM group (14.5% versus 19%). In conclusion, CTM 200 mg bid is as efficacious and as well tolerated as CX 200 mg bid in the treatment of chronic sinusitis in adults.

Anti-Infective Agents↗
PubMed1993

Transiently evoked otoacoustic emission amplitudes change with changes of directed attention.

The effect of a visual and of an auditory task on the cochlea was studied by transiently evoked otoacoustic emissions (TEOAEs). TEOAE amplitude decreased during visual and auditory attention for all 13 subjects tested. The decreased TEOAE activity was noted predominantly within the 960 to 1920 Hz range during visual attention and within the 1920-2880 Hz range during auditory attention. Selective attention, by way of the olivocochlear medial efferent system, modifies cochlear micromechanical properties. Visual and auditory attention act on different areas of the cochlear partition.

Adult↗
PubMed1993

Cleft larynx: management and one-stage surgical repair by anterior translaryngotracheal approach in two children.

Cleft larynx is a rare congenital anomaly which is now being reported with increasing frequency. It is characterized by a midline posterior defect. Two children underwent laryngeal cleft repair by an anterior translaryngeal approach. Tracheotomy was avoided and closure of the anterior laryngofissure was carried out over the nasotracheal tube. The patients were cared for in a pediatric intensive care unit until extubation. Extubation was performed on day 8. The older child had few functional problems and did well whereas the younger child did poorly. In this latter case, the initially successful surgical result was impaired by post-operative aspiration, due to numerous possible factors: gastroesophageal reflux secondarily controlled by Nissen fundoplication, disturbed swallowing as a result more of the cleft repair work than of the surgical approach, or else immaturity of the suction-swallowing reflex.

Child, Preschool↗
PubMed1993

Role of long-term stenting in treatment of pediatric subglottic stenosis.

Twelve cases of childhood subglottic stenosis diagnosed either acquired or congenital were treated using an endolaryngotracheal Montgomery T-tube. Stenting lasted on average 5.6 months. Tracheotomy closure was possible in 75% of cases on average 15.3 months after diagnosis. Tube-linked complications involved the child pulling out, forward migration of the tube out, lower tracheal migration of the tube, clogging and the formation of granulation tissue at its superior extremity. Comparison of outcomes with those for laryngeal surgery (cricoid split, laryngotracheal reconstruction) found in the literature, suggests that long-term T-tube stenting is the optimal treatment for subglottic stenosis where tracheomalacia precludes laryngeal surgery.

Airway Obstruction↗
PubMed1993

Interrelations between transiently evoked otoacoustic emissions, spontaneous otoacoustic emissions and acoustic distortion products in normally hearing subjects.

Active cochlear mechanisms and especially outer hair cells seem to be involved in oto-acoustic emissions (OAEs) genesis. This study sought to investigate basic characteristics of spontaneous otoacoustic emissions (SOAEs), click-evoked otoacoustic emissions (TOAEs) and interrelations between SOAEs, TOAEs and 2f1-f2 and 2f2-f1 distortion product OAEs (DPOAEs) in 135 normally hearing subjects. A gender effect was shown on TOAEs and DPOAEs amplitude, and is attributed to the higher incidence of SOAEs in women (58%) than in men (22%). Moreover, SOAEs presence seems to mask the age effect found, especially at high frequency components, on TOAEs amplitude. A general influence of SOAEs on TOAEs and DPOAEs is shown, especially at frequencies ranging from 1 kHz to 3 kHz, collecting more than 66% of the SOAEs peaks recorded. Lastly, correlations between TOAEs frequency band amplitude and 2f1-f2 DPOAEs amplitude, shows frequency specificity, at least at low frequencies (i.e., from 0.5 to 2 kHz) in agreement with previous works suggesting that the 2f1-f2 DPOAEs generation site is at the geometric mean of the primaries. The same correlations calculated with 2f2-f1 DPOAEs amplitude show frequency specificity at low frequencies i.e., at 800 Hz and 1600 Hz. 2f2-f1 DPOAEs in humans are shown to be generated near the 2f2-f1 frequency region on the cochlear partition.

Acoustic Impedance Tests↗
PubMed1993

Sleep and active cochlear micromechanical properties in human subjects.

In this paper the effect of sleep on the cochlea is studied by transiently evoked otoacoustic emissions (TEOAEs). Amplitude increases considerably (e.g., 4 dB) and the effect of a contralateral noise on the TEOAEs decreases during the night. These modifications can be related to sleep, although there is no link to electroencephalographic sleep stage. During sleep onset, the effect of contralateral noise disappears: this could correspond to a functional rest of the auditory pathway during that period.

Acoustic Stimulation↗
PubMed1993

Functional maturation of cochlear active mechanisms and of the medial olivocochlear system in humans.

The aim of this study was to investigate the functional development of cochlear active mechanisms and of the medial efferent olivocochlear system. Otoacoustic emissions (evoked and spontaneous) were recorded in 42 preterm neonates (conceptional age ranging form 33 to 39 weeks) and a control group of 20 young normal-hearing adults. Medial olivocochlear system activity was examined by coupling evoked otoacoustic emission recording to a contralateral stimulation. Otoacoustic emission recordings were carried out using the Otodynamic ILO88 software and hardware. The stimuli were unfiltered clicks and the contralateral stimulation was broad band noise of 50 and 70 dBSPL delivered by an Adam generator. The results revealed the presence of EOAEs and SOAEs from at least 33 weeks in humans, suggesting that the functional maturation of the outer hair cells is nearly complete at that age. The study further revealed that the contralateral stimulation had no effect on evoked otoacoustic emissions in preterm neonates. The lack of activity observed in medial olivocochlear system indicated functional immaturity here, at least before full-term birth.

Adult↗
PubMed1993

Medial olivo-cochlear system and tinnitus.

A possible role of the efferent system in the mechanisms of tinnitus generation has been put forward by several authors. A simple method for studying the functioning of this system is to compare the amplitudes of otoemissions with and without mild contralateral stimulation. In a recent communication, Veuillet et al. (1991) reported that, on the side of tinnitus, the efferent system of patients suffering from unilateral tinnitus seems to be less efficient than on the other side. The results presented here correspond to those obtained in the very first tinnitus patients submitted to a research protocol exploring systematically the efferent system. When possible, the effectiveness was tested in two ways: globally, using evoked otoacoustic emissions (EOAEs) and, very precisely in the frequency zone of the tinnitus, using cubic distortion product 2f1-f2. Preliminary results obtained in bilateral and unilateral tinnitus sufferers show that a majority of them exhibits, at least in the proximity of the tinnitus, a lack of effectiveness of the efferent system. In some of them, instead of the suppressive effect, an increasing one was even observed.

Adult↗
PubMed1993

Characteristics of transient otoacoustic emissions in patients with sudden idiopathic hearing loss.

In a prospective study of 24 patients hospitalized with sudden idiopathic hearing loss syndrome (SIHLS), tonal audiometry was conducted first at an early stage after onset (Day O), again a second time (Day A, mean = 4.12 days), and again a third time (Day B, mean = 8.71 days). Transient evoked otoacoustic emissions (TEOAE) were recorded on Days O and A elicited by click stimulation. The question under investigation was whether TEOAE presence, TEOAE amplitude or peak amplitudes for the various 200-Hz-wide bands on Day O could be exploited to assess cochlear function, as indicated by pure-tone audiometry on Days A and B. The TEOAE amplitude on Day O was found to be correlated with improvement in tone threshold on Day B at 2 kHz. One significant correlation emerged between the band amplitude on Day O and the audiometric frequency improvement: on Day B between peak amplitude at 1.2 kHz and 1 kHz frequency improvement. From these results, TEOAE could theoretically be a means to assess cochlear functioning during SIHLS for 1 and 2 kHz frequencies. However, correlations are too weak to form the basis of any predictive test that could be clinically useful.

Acute Disease↗
PubMed1993

[Two-stage repair of microtia].

Modifications of the total ear reconstruction technique allowing a two-stage procedure is described. However this is only possible if the soft tissue has not yet been damaged by previous plastic surgery or tympanoplasties. The framework sculpture is improved in order to obtain a posterior conchal wall at the first stage without using a skin graft. A tissue expander is used during the operative time in order to improve the framework coverage. A bone anchored hearing aid is preferred to tympanoplasty when necessary, for bilateral microtia. This method is effective and does not compromise the skin qualities. The osteointergrated implant is put in place during the second external ear reconstruction stage. The total hospitalisation period is no longer than 8 days.

Ear, External↗
PubMed1993

[Progress in phono-audiology: the deaf child].

Functional explorations, the physiopathology of the auditory pathways and centres, morphological investigations, molecular biology, and substitute processes make up the five major themes that best illustrate the progress achieved in phono-audiology. The management of the deaf child is characterized by early and multidisciplinary treatment. Thanks to the technical progress achieved in phono-audiology, the otorhinolaryngologist can apply a humanist medicine.

Auditory Pathways↗
PubMed1993

[Launois-Bensaude disease and sleep apnea syndromes. Apropos of a recent case].

About a recent case of Launois-Bensaude's disease (Madelung's disease) the authors discuss the possibility of complications such as bronchopathy and sleep apnoea syndrome. General anaesthetics have to be performed with care, the anaesthetic risk exists even so during the premedication. Such patients have to be explored before the general anaesthetics by sleep polysomnography.

Humans↗
PubMed1993

[Cochlear implant in children. General principles. Results of the Lyons team].

Cochlear implant is a transductor system used to transform acoustic vibrations into an electric current which stimulates the vestibulocochlear nerve. It may be either extracochlear, the nerve being stimulated through an electrode placed near the cochlea, or intracochlear, the electrode being inserted within the cochlea. Cochlear implantation in children is nowadays a safe and performing method to complete total deafness of sensorineural origin. However it must be only applied to total deafness which fail to show an improvement with conventional acoustic prostheses. In addition, partly for anatomical reasons, partly because of the time required to be sure of the indication, cochlear implantation can only be performed between 18 and 24 months of age.

Child↗
PubMed1993

[Exploration of the efferent system in man: basic and clinical results].

Since 1989, the exploration of the medial efferent system has been possible in human by using a non-invasive technique consisting in the association of the contralateral acoustic stimulation and the evoked otoacoustic emissions (EOAEs). This exploration presents a great interest for fundamental auditory research because it is the sole means of exploring in human these cochlear efferent neurons synapsing at the base of the outer hair cells. The function of this system is still unknown. The interest of such an exploration in clinical research is now becoming obvious such that it would be not only useful but also necessary to establish a precise diagnosis in particular pathologies. The aim of the present paper is to expose basic results obtained on the medial efferent system in normal subjects and above all to present findings for pathological ears, among which figure in particular: retrocochlear pathologies, hyperacousia, noise-induced hearing loss, tinnitus. In addition to the diagnostic interest of the exploration of the medial efferent system, a knowledge of its functioning will probably allow its role in audition to be determined.

Acoustic Stimulation↗
PubMed1993

[Subglottal stenosis following intubation in children].

BACKGROUND: Subglottal stenosis following intubation of children is infrequent, but significant. It is therefore necessary to know more about predisposing factors. MATERIAL AND METHODS: The files of all the 1,006 children who were intubated from 1982 to 1989 were studied. The following data were analysed: weight, height, locality of intubation, type and diameter of tube, reason for intubation, duration of intubation, delay and type of clinical signs of subglottal stenosis, treatment of this complication. RESULTS: Twelve children (1.5%) developed subglottal stenosis; 9 were 5 months to 7 years old; the other 3 were neonates, 2 of them with a very low birth weight. The disease responsible for intubation was neurologic in origin in 6 cases, respiratory in 4 and hemodynamic in 2. The tube used for 4 children was too large, based on standards for age and weight. The mean duration of intubation was 21.1 days (1-129 days). Primary failure to extubate usually revealed subglottal stenosis, which was assessed by laryngoscopy. It was necessary to reinsert a tube for a mean duration of 20.2 days (4-41 days) in 11 of the 12 children; all patients received corticosteroids. 6 children required tracheostomy for 37 to 365 days. Dilation was necessary in 7 children. Finally, 9 children fully recovered, 1 has an asymptomatic persistent stenosis, 1 is still intubated with severe neurologic sequellae and 1 died accidentally, probably as a result of obstruction by tube dilation. CONCLUSION: Stenosis remains a severe complication of intubation. The diameter of the tube is probably the most aggressive factor. It seems preferable to use a smaller, therefore cuffed tube and to secure the airways, if necessary, by inflating the cuff.

Child↗