Intra-individual variability in tinnitus patients : current thoughts and perspectives.

Most tinnitus studies have attempted to compare groups of individuals, thus revealing inter-individuals differences, i.e., variations between compared subjects. For methodological reasons, inter-individual studies cannot take into account the variability of tinnitus experience, which has been known for decades to be relevant in daily practice with tinnitus patients. The concept of intra-individual variability has been promoted in the research literature, in order to shed light on this aspect of individual perception. In previous studies, unrelated to hearing, the concept of intra-individual variability implied inclusion of the environment (i.e., physical and social interactions) as a factor of individual performance. In tinnitus research, we believe that the concept of variability (within a person) could find a place beside the concept of variation (between groups of subjects). In this paper, four perspectives of tinnitus experiences from the clinical and research fields are described: (1) ENT consultation; (2) short-term group psychotherapy; (3) psychodynamic psychotherapy; and (4) clinical psychological research. Intra-individual variability stresses the importance of defining tinnitus in a dynamic way, contrary to the current definition of tinnitus as the perception of sound(s). In clinical practice, it is useful to embrace the perspective of the perceiver of tinnitus, and to include social and cultural circumstances as well as audiological/physical changes.

French Society of ENT (SFORL) guidelines (short version): Audiometry in adults and children.

INTRODUCTION: French Society of ENT (SFORL) good practice guidelines for audiometric examination in adults and children. METHODS: A multidisciplinary working group performed a review of the scientific literature. Guidelines were drawn up, reviewed by an independent reading group, and finalized in a consensus meeting. RESULTS: Audiometry should be performed in an acoustically controlled environment (<30dBA); audiometer calibration should be regularly checked; and patient-specific masking rules should be systematically applied. It should be ensured that masking is not overmasking. Adult pure-tone audiometry data should be interpreted taking account of clinical data, speech audiometry and impedancemetry. In case of discrepancies between clinical and pure-tone and speech audiometry data, objective auditory tests should be perform. In children aged 2 years or younger, subjective audiometry should be associated to behavioral audiometry adapted to the child's age. In suspected hearing impairment, behavioral audiometry should be systematically supplemented by objective hearing tests to determine and confirm the level and type of hearing impairment.

Summating potential and water balance in Meniere's disease.

The summating potentials (SP) to free-field 1-, 2-, 4-, and 8-kHz, 90-dB HL tone bursts were recorded by means of transtympanic electrocochleography in 45 patients divided into three groups: those with Meniere's disease, those whose diagnosis was uncertain, and control subjects. The similarities across frequencies between the human SP (promontory) and the experimental SP (DIF component from basal turn) suggest that the SP recorded in electrocochleography originates mostly from the base of the cochlea; negative values were observed at low frequencies (1 to 2 kHz), positive values at high frequencies (8 kHz). Patients with Meniere's disease showed significantly larger SP values than control subjects. The effect of orally administered glycerol on the SP and action potential amplitudes was evaluated by means of automated recordings repeated every 5 minutes. Summating potential values were remarkably constant in the control group. A decrease in SP absolute amplitude was observed in most patients with Meniere's disease and some subjects with uncertain diagnoses, specifically at low frequencies. These changes were frequently associated with action potential amplitude and auditory threshold improvements at low frequencies. It is assumed that the glycerol-induced SP changes at low frequencies are related to modifications in the low frequency mechanical response of the basilar membrane at the basal turn.

Frequency selectivity: reliability of electrocochleographic measures with iso-intensity masking.

In a group of 12 normal or hearing-impaired subjects, frequency selectivity was determined psychoacoustically and electrophysiologically with the fast ECochG iso-intensity masking procedure, using a 4 kHz test tone and simultaneous pure-tone masking. Psychoacoustic curves measured twice for each subject were reproducible and showed a broadening related to hearing loss. The curves determined with ECochG repeated two or three times for each subject varied greatly for half of the subjects and their widths were not related to hearing loss. ECochG measures were reproducible in the cases where the amplitude of the response was larger. The data set out the conditions and limits of this ECochG procedure for clinical use.

Intracochlear electrical tinnitus reduction.

Several reports have indicated that some cochlear implant patients experience a reduction in their tinnitus while listening to noise or speech. In the present study, two patients reporting bilateral tinnitus were selected from a group of adults with the Nucleus cochlear implant. They rated their tinnitus loudness and severity and completed the Tinnitus Handicap Questionnaire. The stimuli for electrical stimulation were charge-balanced pulse trains of various repetition rates (frequencies) and inter-electrode distances. A range of electrodes was chosen in each subject, including basal, medial and apical electrodes. For each condition, the hearing threshold level and the uncomfortable loudness level were determined. A range of stimulus levels between these two values were presented randomly. After each presentation, the patients rated the stimulus loudness and the tinnitus loudness on a 0 to 100 scale. These judgements were used to carefully determine the psychometric function between stimulus level and stimulus loudness, and between stimulus level and tinnitus loudness. All the parameters explored were important for maximizing the relationship between tinnitus reduction and stimulus loudness. First, the effectiveness of electrical stimulation in tinnitus reduction depended on the place along the cochlear partition. Second, a pulse rate of 125 Hz showed the greatest efficiency in terms of the current level needed to suppress tinnitus. Third, these two subjects showed rather poor performances in speech perception when using their speech processor in the usual condition and the hypothesis of an influence from tinnitus annoyance is suggested in addition to some more classical predicting factors of speech recognition in cochlear implant users.

Audiometric and electrophysiological correlations in sudden deafness.

Electrophysiological measures were collected over 3 years in 61 cases of sudden deafness. Electrocochleography (ECochG) and Auditory Brainstem Responses (ABR) using click stimuli were recorded down to threshold and compared with pure-tone and speech audiometry data. This study was intended to precise 1) localization of the disorder, 2) prognosis, 3) analysis of the contribution of different frequencies in click-evoked responses. The following results are: 1) In most cases the observations indicated that the inner ear was affected. 2) However, in 19 cases electrophysiological measures revealed a retrocochlear involvement. Four acoustic neuromas were evidenced by CT scan. In 3 of these, audiometric and electrophysiological thresholds returned merely to normal levels after medical treatment, while brainstem responses remained delayed. Thus in these cases recovery would seem to be related to release of vascular compression in the auditory internal meatus. 3) When the latencies of the VII nerve potential (N1) and wave V (PV) were short, and the therapy undertaken early, a good recovery was often obtained. 4) When recovery occurred on low frequencies only, the electrophysiological responses to the click showed slight latency increases.

Short-term effectiveness of medial efferents does not predict susceptibility to temporary threshold shift in the guinea pig.

The 2f1-f2 distorsion product (DPOAE) was measured in conjunction with contralateral noise to evaluate the short-term effectiveness of the olivocochlear efferents in guinea pigs (GPs). An attenuation effect was observed predominantly between 1 and 6 kHz when primary tones were set at 65 dB SPL (contralateral noise of 55 dB SPL). Subsequently, GPs were exposed to a 2 kHz tone of 87 dB SPL for 40 min, using DPOAEs as an estimate of cochlear sensitivity. The response of the cochlea appeared variable. In order to investigate whether effectiveness of efferents plays a role in temporary threshold shift (TTS), the responses of the cochlea to overstimulation were classified into three groups: i) clear cochlear change with complete recovery or actual TTS (group A1); ii) clear cochlear change with incomplete recovery (group A2); iii) mild or no change in cochlear function (group B). No relationship was found between the attenuation effect measured before noise overexposure and the susceptibility to TTS. Animals with a significant attenuation effect could fit into any of the three groups. In addition, the recovery from loud sound exposure was not paralleled with the changes occurring over time in the attenuation effect. Therefore, the conclusion that short-term effectiveness of medial efferents does not predict susceptibility to TTS in the GP is suggested.

Electrocochleographic measures of cochlear frequency selectivity in hearing loss of cochlear origin.

One of the basic functions of the cochlea is to separate out the frequency components which are present in complex sounds. This frequency selectivity can be measured objectively in the clinic from the compound action potential (AP) during transtympanic electrocochleography, using a two-tone masking paradigm. An AP is evoked by a test tone near to threshold, and a measure is made of the frequency bandwidth over which this AP can be suppressed by a continuous pure tone masker. In normal-hearing subjects, this frequency range is 0.17-0.39 octaves (test tone pip at 4 or 8 kHz). In patients with cochlear deafness, this bandwidth is greatly enlarged, ranging from 0.42-2.2 octaves. Some observations suggest that a deterioration in frequency selectivity can occur before any important threshold elevation. The early detection of this could be a warning sign of potential cochlear susceptibility. In the clinic the measure is already of use: a deterioration is a positive indication of cochlear involvement in a hearing loss.

Development of capacities of communication and socialization in young deaf children: utility of a common assessment protocol for implanted or hearing aid equipped children.

Pediatric cochlear implantation has attracted a growing interest among health professionals, but it has also encountered opposition on the deaf community. It is therefore incumbent upon the medical teams that carry out this procedure to furnish scientific arguments demonstrating the benefits of this technique for the age group 2 to 4 years and its innocuousness for the child's later psychological development. With this in mind, we have elaborated an assessment protocol adapted to very young deaf children, regardless of whether they have implants or hearing aids. The present report describes two tests of the protocol, chosen because they meet needs which until now have been insufficiently, or not, met. The first of these tests aims at assessing, as early as the age of two, oral and gestual production thanks to sequential images. The second test is the most original element of our psychological protocol: analysis of the child's interactional attitudes through filmed game situations. The initial results from a group of children recently implanted and from another group equipped with hearing aids are presented. These children continue to be seen at regular intervals. It is reasonable to hope that this kind of study will afford objective arguments to the debate in progress.

Long-term outcome of childhood hearing deficiency.

This report is based on the questionnaire responses of 95 young hearing-impaired adults (39 with moderate, 20 with severe and 36 with profound hearing loss) who were investigated in the department of paediatric audiology during childhood. Half of the individuals were educated in ordinary school (integration) and half in an institution for hearing-impaired children. Responses on social and professional insertion were compared with audiometric threshold and educational setting. Results indicate that both hearing level and educational environment influence current mode of communication and use of hearing aids. Familial factors also seem to have an influence. Oral communication is a poor predictor of employment, whereas professional qualifications enhance the chances of finding a job. Obtaining a non-professional degree appears to be unsuited for improving the employment rate of the hearing-impaired child.

Recent Advances in Tinnitus.

Tinnitus can be the most debilitating symptom faced by people with hearing impairments. In the past 10 years, there has been a large increase in tinnitus research and in the development of clinical protocols. New animal models and physiological procedures provide an important contribution to the understanding and measurement of tinnitus. The annoyance of tinnitus likely depends on its loudness and the psychological makeup of the patient. The loudness of a person's tinnitus can be compared with the equivalent loudness of a 1000 Hz tone in a normal ear. Several questionnaires have recently been introduced to quantify the handicap caused by tinnitus. Tinnitus maskers are apparently ineffective for most patients but they can be helpful in a few patients. Medications are largely ineffective in reducing tinnitus in most people. However, several psychological techniques for reducing the stress associated with tinnitus are currently under investigation, and preliminary results show some promise. Tinnitus can be reduced by electrical stimulation in a few patients, and this is also an important area for future research.

The prognostic value of the stapedius reflex in peripheral facial palsy.

Stapedius reflex can provide useful prognostic information in FPs when the middle ear is normal. Its preservation may have a favorable significance in partial FP and Bell's palsy. Its loss, even though less reliable, can also have some value as an indicator for a poor prognosis in patients with total and herpes zoster FPs. Most importantly, our findings have shown that the SR alone is not sufficient to be of prognostic value, but is useful if combined with other clinical parameters and electrical responses.

[Normovolemic hemodilution in the treatment of sudden deafness]. / Apport de l'hémodilution normovolémique au traitement des surdités brusques.

After the apparition of a sudden deafness, 45 patients (22 men and 23 women, with a mean age of 44 +/- 14.9 years) were treated with normovolaemic haemodilution performed with dextran 60. They were placed into 4 groups depending on their hearing loss: total loss: 10 cases; severe loss: 90 to 70 db. 13 cases; moderates loss: 65 to 40 db, 14 cases, slight loss: less than or equal to 35 db, 8 cases. The mean time between the onset of the hearing loss and treatment was 9.3 +/- 12.4 days. The initial mean haematocrit was 44.8 +/- 3.8% and mean haematocrit after haemodilution was 33.1 +/- 2.8%. For 51% of the patients, an almost total recovery was obtained. In 15.5% of cases, recovery was between 25 to 50% of the hearing loss, and in 33.3% of the patients recovery was negligible. We did not find any relationship between hearing recovery and initial haematocrit. The best results were obtained in the group of patients treated early. Hearing gain was significatively better if delay in starting treatment was less than 7 days. There was a relationship between the initial hearing loss and the final recuperation. These results suggested that haemodilution increased labyrinth microcirculation and oxygenation of the cochlear sensory cells, reversing the ischaemic insult to these cells.

[Value of the association of normovolemic dilution and hyperbaric oxygenation in the treatment of sudden deafness. A retrospective study]. / Intérêt de l'association hémodilution normovolémique-oxygénothérapie hyperbare dans le traitement des surdités brusques à partir d'une étude rétrospective.

The multiple treatments of sudden deafness shows how this pathology still remains quite unknown. The authors present a retrospective study of 87 patients treated by normovolemic hemodilution associated to hyperbaric oxygenation. They obtain a total à 60% of significant recovery (ratio between hearing gain and initial hearing loss, above 25%) and in severe hearing loss (threshold between 70 and 90 dB) 60% of good results (ratio above 50%). The importance of the initial form of audiogram and the presence of dizziness as prognostic factors is not confirmed. On the other hand, the evolution of tinnitus is correlated with the deafness and it is a supplementary means to evaluate the therapeutic efficiency. Moreover the persistence of tinnitus represents an important after effect. Sudden deafness still remains a medical emergency and the delay for carrying out any treatment should be as short as possible. On the other hand it is possible to reduce hospital stay by two sessions of hyperbaric oxygenation per day.

[Tinnitus: peripheral and central aspects]. / Acouphènes: aspects périphériques et centraux.

Tinnitus is often related to a peripheral impairment which seems to trigger an abnormal autonomous functioning of the central auditory system. Moreover peripheral stimulations may diminish, and even suppress their perception, either through masking or through inhibition of an aberrant neuronal activity. Here we present an experimental model of peripheral deafferentation in which a decrease of neurochemical activity is observed in the brainstem auditory nuclei, followed by a progressive recovery after the peripheral destruction. This activity could represent a central morphofunctional correlate of tinnitus. Development of experimental models of tinnitus must be continued. Such models should allow the study of the basic physiological mechanisms behind tinnitus and suggest some therapeutic approaches which could be objectively evaluated.

[Clinical value of tuning curves or frequency selectivity curves]. / Intérêt clinique des courbes d'accord ou courbes de sélectivité fréquentielle.

A simplified method, useful in clinical practice, is described in order to study the frequency selectivity in various conditions. The patient is asked to indicate the levels of pure tones which are necessary to mask completely the perception of an intermittent probe. The resulting psychoacoustic tuning curves are characterized by a more or less narrow bandwidth which reflects the ability to resolve simultaneously presented sounds. Several circumstances where these tuning curves are helpful, are presented: assessment of tinnitus, Menière's disease, unclear impairment of speech intelligibility. Therefore, this technique appears as a valuable tool which can be used in addition to the usual audiometric and electrophysiological tests battery.

[Role of electrophysiology in the current diagnosis of deaf children]. / Place de l'électrophysiologie dans le diagnostic actuel de l'enfant sourd.

The role of electrophysiology (auditory evoked potentials) in children up to 3 years old was studied through the feasibility and results of subjective audiometry. In children over six months old, subjective tests are performed systematically or at least tried before using electrophysiology. Electrophysiology is required when audiometry is impossible, and it is often performed when audiometry is abnormal. When subjective tests were not performed first, either because the child is too young or shows a developmental retardation, and the electrophysiological tests are abnormal, it is absolutely necessary to obtain an exact level of hearing as soon as possible using subjective tests. The results of a study on 244 electrophysiologically tested children between the 0 and 3 years of age are presented briefly. In 73% of the cases, the auditory brainstem responses were sufficient for clarifying or confirming the subjective tests. In 27%, they had to be completed be an electrocochleography (ECochG) under general anesthesia. The information based on the ECochG and the comparison data between the ECochG and subjective thresholds are presented. On one hand, this study highlights the double complementarity between audiometry and electrophysiology on the other, the brainstem potentials and ECochG.

[ORL aspect of meningioma of the cerebellopontine angle]. / Aspect ORL des méningiomes de l'angle ponto-cérébelleux.

Through 14 recent cases, the authors review the main clinical syndromes leading to the diagnosis of petrous and brain-stem meningiomas. The cochleovestibular syndrome, the most frequent amongst them, recalls the symptomatology of an acoustic neuroma. The jugular foramen syndrome is similar to that seen in jugulo-tympanic paragangliomas. The middle ear tumor syndrome is specific to primary or secondary intrapetrous tumors. The positive diagnosis of meningiomas belongs to the field of CAT scares and mainly of NMR, which define morphological characters, none of them being specific: oval shape, the closed angle sign, intratumor calcification, hyperdensity, osseous changes on the posterior aspect of the petrous bone NMR permits a very precise localization and definition of the tumor which is necessary among the per-op studies. This decreases the occurrence of once frequent surgical surprises.

[Multi-frequency impedance measurement and Meniere's disease. Analysis of the results of TEFLAG]. / Impédancemétrie multifréquentielle et maladie de Ménière. Analyse des résultats du TEFLAG.

We present today our preliminary results of the TEFLAG test performed on 58 patients suffering from Meniere's disease. This test completed in 1993 has already led to a 4-stage classification of noise induced hearing losses. On the one hand, it is based on the morphological study of susceptance B curves, and on the other hand, on the study of the resonant frequency (RF) of the annular ligament of the stapes, provided by a multifrequential impedancemeter. The endolymphatic hydrops coming with the Meniere's disease practically always cohabits in the intercritical period with the decrease of the perilymphatic pressure of the scala vestibuli, which is shown in the morphology of Stage IV curves especially, and the decrease of the annular ligament rigidity. Inversely, during the vertigo or around, we mainly have stage I curves, and an increase of the stapes annular ligament resonant frequency (RF), testifying the labyrinthic hydrops, which is the physiopathological essence of the Meniere's disease.

[Sudden deafness: a randomized comparative study of 2 administration modalities of hyperbaric oxygenotherapy combined with naftidrofuryl]. / Surdités brusques: étude comparative randomisée de deux modes d'administration de l'oxygénothérapie hyperbare associée au Naftidrofuryl.

Hyperbaric oxygen therapy is one of the numerous therapies which have been proposed in the management of sudden deafness. It is presumptuous to claim the efficiency of any treatment in a pathology where both the origin and the actual rate of spontaneous recovery are unknown. The grounds of therapies are therefore empirical but the need of urgent therapy is dictated by ethics. This study compares the effects of hyperbaric oxygen therapy in two groups of patients; according ot their order in randomization the subjects were treated either at a rate of 1 session or 2 sessions per day. Hyperbaric oxygen therapy was associated with infusion of Naftidrofuryl to counteract the vasoconstrictive effect of increased oxygen pressure in blood. Steroids were also administered simultaneously to avoid, for the same reasons, cerebral oedema. Normovolemic hemodilution (Dauman et al. 1983) was systemically performed in all the patients preliminarily to hyperbaric oxygen therapy, in order to reduce the haematocrit and thus facilitate blood supply. The efficiency and the side effects were similar in the two groups, provided that some principles in the selection and the monitoring of the patients were respected. The rate of 2 sessions of hyperbaric oxygen therapy per day has obvious advantages in view of health policy, but it requires the hospitalization of the patient and should be restricted to the younger subjects.