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Biomedical subjects

P Bonfils

Publications and source records attributed to P Bonfils.

At least 19 recordsLinked to original sources
PubMed1995

Screening for neonatal and infant deafness in Europe in 1992.

Many methods of screening for hearing impairment are available. The aim of our study was to determine which ones were really used in 1992. At the request of the British Audiology Society, we conducted an inquiry into the organization of screening for deafness in neonates and infants in Europe. In practice all 6-9 month-old infants are tested with behavioural tests in every country. For the neonates, generally only those at risk for hearing-impairment (about 5%) were tested. The most widely used tests were behavioural ones. Only specialized centers used transient evoked otoacoustic emissions (TEOAEs). This last test assesses the active mechanical properties of the cochlea and allows detection of even mild or unilateral sensorineural deafness.

Audiometry↗
PubMed1995

[Deafness in the neonatal period: basis for screening].

Deafness must be recognized in infancy in order to reduce auditory disability to a minimum. To achieve this, it is important to implement screening programmes as soon after birth as possible. In the United States, the Joint Committee on Infant Hearing recommended in 1982 that identification of hearing loss should be screened in the neonatal period. This early detection is now considered critical for optimal rehabilitative outcome. This paper presents the "state of art" neonatal screening principles and procedures. In France, neonatal screening programs for auditory dysfunction are not consistent with these principles. Evoked otoacoustic emissions represent an important advance in screening for hearing loss in normal neonates and babies from neonatal intensive care units. This method records very low intensity sound energy released by the cochlea in response to a brief sound stimulation. These otoacoustic emissions show promise as a rapid, cost-effective means of quickly discharging all babies with normal peripherical auditory systems.

Deafness↗
PubMed1995

Transient-evoked otoacoustic emissions and high-frequency acoustic trauma in the guinea pig.

Transient-evoked otoacoustic emissions (TEOE) disappear when hearing loss exceeds 40 dB in the range 1-4 kHz, due to impairment of cochlear outer hair cells. Early screening of sensorineural hearing losses is based on this finding. However, little is known as to the frequency specificity of TEOE abnormalities in a damaged cochlea. TEOE were recorded in 18 normally hearing guinea pigs in a range from 1.5 to 5 kHz before and after exposure to loud pure tones (3-10 kHz, 95-105 dB SPL, 1-10 min). The thresholds of eighth-nerve compound action potentials (CAP) were monitored with a round-window electrode; it was confirmed that acoustic overexposure resulted in typical high-frequency threshold elevations (10 to 50 dB). Most TEOE components were found at lower frequencies at which CAP thresholds did not change. However, a significant linear regression was found between their amplitudes and the percentage of basal cochlea with unaltered CAP thresholds (r = 0.69, p < 0.0001). Two alternative hypotheses are proposed to account for this correlation. Either acoustic trauma induced some minute cochlear damage at places tuned to low frequencies and TEOE were more sensitive to it than CAP thresholds, or significant contributions to lower-frequency TEOE came from the most damaged cochlear places tuned to much higher frequencies.

Acoustic Stimulation↗
PubMed1994

[Cervicofacial cancerology: complications of implantable systems of venous access. Prospective study].

OBJECTIVE: Implantable systems for venous access are widely used in cervicofacial cancer. We prospectively evaluated complications related to this type of venous access in our cancer patients. METHODS: From September 1991 to September 1993, an implantable system for venous access was installed in 164 patients with epidermoid carcinoma of the upper respiratory and digestive tracts. The systems were implanted in the subclavian vein by 20 different operators (mean number of implants per operator = 8.2). All catheters were tunnelized. Chemotherapy was a combination of 5 fluorouracil and cisplatinum. RESULTS: Immediate complications included impossible implantation (n = 12, 7.3%), pneumothorax (n = 5), false passage (n = 4), haematoma (n = 3), arterial puncture (n = 2) and abscess of the thoracic wall (n = 1). During use, complications included extravasation (n = 4), catheter thrombosis (n = 2), venous thrombosis (n = 2) and infection at the site of implantation, desinsertion of the catheter from the chamber, haematoma at the site of implantation and septicaemia (n = 1 each). The rate of complications was related to implantation (17% of the implantations) or to use (8%). CONCLUSIONS: The rate of complications due to implantable venous access systems is relatively low, suggesting that these systems are acceptable for ambulatory chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Role of congenital hypothyroidism in hearing loss in children.

No significant difference was found for the auditory thresholds at conversational and high frequencies between 42 children with congenital hypothyroidism treated with L-thyroxine and an age-matched control group, regardless of the cause of the thyroid failure or hormone level and the age at the start of treatment.

Adolescent↗
PubMed1994

Auditory threshold evaluation by distortion-product oto-acoustic emissions using decision support system.

Distortion-product oto-acoustic emissions (DPOEs) were measured in 102 normal-hearing and hearing-impaired ears to examine the sensibility, specificity, positive predictive value and negative predictive value of this test in a real clinical setting using two decision support systems. The first model only considered the presence or the absence of DPOEs in response to a 52 dB SPL stimulation intensity. The second model used two consecutive tests: i) the presence or the absence of DPOEs in response to a 52 dB SPL stimulation intensity, and ii) evaluation of the slope of each DPOE input-output function. The sensitivity of these two models varied between 1 and 0.83 whereas the specificity varied between 0.95 and 0.72 as a function of the frequency tested. The first model proved to be a very sensitive test, but the introduction of a second criterion of decision (i.e., the slope of DPOE input-output function) did not enhance the validity of the test.

Acoustic Stimulation↗
PubMed1994

[Role of the basal cochlea in the genesis of evoked acoustic oto-emissions in the subject with normal hearing].

The aim of this study was to determine the role of the basal part of the cochlea (8-16 kHz) on the genesis of evoked otoacoustic emissions (EOEs) in normally hearing subjects (0.25-8 kHz thresholds below or equal to 20 dBHL). This study was realized on 43 subjects. The EOEs were generated by a linear click of 0 dB (ILO88 Ref.). The high-frequency (8-16 kHz) audiometric thresholds varied between 30 and 74 dBHL while conventional audiometric thresholds were below 20 dBHL. Correlation studies between EOE amplitude and audiometric thresholds were statistically significant only when the high frequency thresholds were considered. Those data are a new argument for the hypothesis that EOEs are generated by the global cochlear activity.

Adult↗
PubMed1994

[ORL surgery in Albucasis's treatise on surgery. A vision of cervicofacial surgical therapeutics in the year 1000].

The work of the famous Arab doctor, Albucasis, is not well known to head and neck surgeons. However, the thirtieth time of his treatise on medicine is essentially a surgical textbook and includes many. Facts concerning otorhinolaryngology. Albucasis's complete work is an exhaustive compilation of late tenth century medical knowhow which ensured the link between ancient medicine, essentially of Greek origin, and modern western medicine. The important work of Jewish and Arab physicians in the early and late Middle Ages was necessary for the transmission of knowledge from the ancient near last to the modern western world. Among Albucasis's descriptions of surgical techniques, tonsillectomy and trachestomy are particularly interesting. In order to accurately formulate indications for surgery, Albucasis endeavors to present the signs and symptoms of pathological conditions requiring surgical treatment. Finally, Albucasis reveals himself to be a humanist, as well as a physician and surgeon.

History, Medieval↗
PubMed1993

Temporal patterns of transient-evoked otoacoustic emissions in normal and impaired cochleae.

The spatial distribution of outer hair cells that participate in generating transient-EOE frequency-components has been investigated in man. According to several models (e.g. Wilson (1990) Hear. Res. 2, 527-532; Zwicker (1986) J. Acoust. Soc. Am. 80, 154-162; Wilson and Kemp (Eds.), Cochlear Mechanisms, Structures, Functions and Models, Plenum Press, NY), EOEs result from interferences between broadly distributed contributions, responsible for their long frequency-dependent delay. This work presents an analysis of the temporal patterns of click- and tone-burst-EOEs in human ears when contributions to EOEs are reduced by noise-induced lesions with audiometric notches centred around 4 kHz (N = 46). Although the auditory thresholds at the frequencies of the studied EOE-components were always normal, these components exhibited drastic and predictable changes compared to normal control ears (N = 40). (1) Their temporal pattern at the highest EOE frequency fmax just below the audiometric notch appeared to be determined by the cochlear state at high frequencies (6 to 8 kHz). Either it was normal and the EOE exhibited a complicated beat-structure, or it was impaired and the time envelope of the EOE was simple. In contrast, any type of time pattern could be observed in normal ears. (2) The temporal patterns of EOEs one octave below fmax always presented many beats and short delays. The proposed interpretation is that contributions to a transient-EOE component at frequency f can come from distant basal cochlear areas, i.e. more than 1 and sometimes 1.5 octaves from the place tuned to f. Therefore, the possible relationships between transient-EOEs and tuning mechanisms which presumably involve only a small number of OHC need further investigations.

Acoustic Stimulation↗
PubMed1993

Exploration of cochlear function by otoacoustic emissions: relationship to pure-tone audiometry.

The amplitudes, growth functions and detection thresholds of evoked otoacoustic emissions (EOE) were measured in 44 normally hearing subjects and 138 patients with two categories of cochlear dysfunctions: (a) acoustic trauma; and (b) presbycusis. Separate sets of experiments were also performed: (a) detection of stimulus frequency emissions; and (b) click EOE. EOE properties were studied around 2 kHz, 1 kHz and 0.75 kHz (+/- 0.1 kHz). A partial correlation and multivariate analysis was carried out to investigate the relationships between EOE properties and puretone auditory thresholds (from 0.25 to 8 kHz, half-octave steps). For each experiment and each frequency, only one highly significant correlation was found, linearly relating the n kHz EOE threshold with the hearing threshold at 2n kHz: there was a shift of about one octave between EOE amplitudes and audiometric data. This means that EOE thresholds give no direct information about the local cochlear state. A simplified model has been implemented, which assumes that EOE thresholds and amplitudes are proportional to the total number of residual active sites along the organ of Corti, i.e., to the total length of active basilar membrane towards the base of the cochlea. It is shown that this model accounts for the results revealed by the statistical analysis and closely fits the experimental data.

Acoustic Stimulation↗
PubMed1993

[Does the use of nasal vasoconstrictor agents change tomodensitometric images of nasosinusal polyposis?].

This study compared the results of the CT scan of the paranasal sinuses in nasal polyposis patients before and after a topical vasoconstrictor application on the nasal mucosa. No change have been observed either on the maxillary and ethmoidal sinuses, or the middle meatus. On the other hand, an important retraction was observed on the nasal mucosa, in particular on the inferior turbinate. Then, the application of a topical vasoconstrictor on the nasal mucosa does not seem necessary in order to explore the sinuses in patients with nasal polyposis.

Adult↗
PubMed1993

[Reoperation of tumors of the parotid gland. Technical approach and consequences for the 7th cranial nerve. Apropos of 22 cases].

Second or more surgical procedures on parotid are usually difficult and may induce injury on the facial nerve. The authors report their experience about 42 patients. The choice between a total parotidectomy or a surgical excision of a tumor depends of the number of surgical procedure, the type of initial procedure and the histological type of the tumor. Second surgical procedures for a wrong initial histological diagnosis (11 cases) were always a total parotidectomy with facial nerve preservation. The risk of a partial or total facial palsy is higher after several recurrences (3 of 8 cases). The facial nerve had to be resected in 3 of 9 cases of malignant tumors recurrences. The initial treatment of a tumor of the parotid must be radical so it can prevent for further surgical procedures and then avoid a facial nerve injury.

Adult↗
PubMed1993

[Screening of deafness in the young child. Value, techniques and initial results of products of acoustic distortion].

Distortion-product otoacoustic emissions are otoacoustic emissions evoked by two pure tones called primaries and proposed in order to provide a frequency specific investigation of the cochlea. This paper first reports complete input-output functions of distortion-product otoacoustic emissions for conventional audiometric frequencies in a population of 35 neonates without any risk for cochlear function. Distortion-product otoacoustic emissions could be useful, in association with evoked otoacoustic emissions and comportemental audiometry, to precisely evaluate the peripheral auditory system in infants and neonates.

Audiometry↗
PubMed1992

Distortion-product otoacoustic emissions. Values for clinical use.

Distortion-product otoacoustic emissions are otoacoustic emissions evoked by two pure tones. They are proposed as a frequency-specific test of the mechanical properties of the cochlea. The aim of this study was to measure distortion-product otoacoustic emissions in a clinical setting to establish the most interesting values suitable for clinical use and the clinical interest of the method. The statistical analysis of the data points out some clinically interesting values: (1) a screening limit value of 30 dB hearing level and when measuring distortion-product otoacoustic emissions in response to 52 dB sound pressure level for studying active frequency selective mechanisms; (2) a screening limit value of 50 dB hearing level and when measuring distortion-product otoacoustic emissions in response to 72 dB sound pressure level for studying passive cochlear mechanisms; and (3) the slope of the input-output function. All physiologic properties of the cochlea fit with these basic distortion-product otoacoustic emission properties. These criteria can be used whatever the population studied and the material used for distortion-product otoacoustic emissions recordings. Distortion-product otoacoustic emissions can be used as a screening test to separate (1) subjects with normal hearing and subjects with a hearing threshold above 30 dB hearing level (distortion-product otoacoustic emissions in response to a 52 dB sound pressure level "primaries" [ie, pure tones] stimulation intensity), and (2) patients with a hearing threshold above or below 50 dB hearing level (distortion-product otoacoustic emissions in response to a 72 dB sound pressure level primary stimulation intensity). Distortion-product otoacoustic emissions cannot be used as a more precise audiometric test.

Adolescent↗
PubMed1992

Analysis of possible interactions of an attentional task with cochlear micromechanics.

Several contradictory studies have been published regarding the effect of selective attention on cochlear mechanics, possibly modulated through efferent pathways. Click-evoked otoacoustic emissions have been proposed as a highly sensitive tool for testing the hypothesis of such a modulation. In this study, two other types of evoked otoacoustic emissions (i.e. distortion products and stimulus frequency emissions between 1 and 4 kHz) were measured on 20 normal subjects in absence and presence of a visual selective attention task. The duration of measurements at a given frequency was short enough to eliminate possible artefacts due to long-time averaging. No significant change was observed in these signals, considered as probes of cochlear micromechanics. It is concluded that in this set of experimental conditions, selective attention has a negligible effect on peripheral sensitivity.

Acoustics↗
PubMed1992

Spontaneous and evoked otoacoustic emissions in preterm neonates.

Spontaneous (SOEs) and evoked otoacoustic emissions (EOEs) were recorded in a group of preterm neonates (N = 134 ears) in order to study the basic properties of SOEs and EOEs as a function of gestational age. In the study, it was found that: 1. EOEs were recorded in 93% of the tested ears; 2. SOEs were recorded in 61% of the tested ears; 3. there were no statistically significant variations of EOE amplitude with gestational age; 4. EOE spectrum did not vary with age; and 5. the two main factors influencing EOE amplitude were the SOE presence and the fast Fourier transform spectrum, especially the lower limit of the spectrum. Thus, the maturation of outer hair cell properties appears to be complete at 32 weeks of gestational age. Because a number of infants at risk for hearing loss are preterm babies, screening for EOEs, an objective, rapid, and nontraumatic technique, may prove useful in evaluating peripheral auditory dysfunction in preterm neonates.

Cochlea↗