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O Deguine

Publications and source records attributed to O Deguine.

At least 19 recordsLinked to original sources
PubMed2001

Sensorineural hearing loss and otosclerosis: a clinical and radiologic survey of 437 cases.

The aim of this study was to determine if a relationship exists between bone level thresholds and the extension of otosclerotic foci within the otic capsule. The study consisted of a retrospective case review in a university hospital. We included patients who underwent surgery for otosclerosis in our department and who had a CT scan prior to surgery. We analyzed the data charts and CT scans of 437 cases (386 patients). On CT scan, we distinguished patients with fenestral otosclerosis and/or with a pericochlear focus. A pericochlear focus could be extended (Group 2) or not (Group 1) to the cochlear endosteum. Data for Groups 1 and 2 were compared with those for the control group of all patients for whom CT scan showed no cochlear focus (Group 3). Of the 437 CT scans, 399 were positive (91.3%). An anterior focus was reported in 305 cases (69.8%), a footplate thickening in 21 cases (4.8%) and both anomalies were encountered in 60 cases (13.7%). A pericochlear focus was reported in 53 examinations. This focus was extended to the endosteum in 14 cases (26.4% of the pericochlear foci). In Group 1, preoperative air conduction (AC) thresholds were significantly lower than in the control group (p < 0.05). The air--bone gap was also significantly larger in Group 1 (p < 0.05). Bone conduction (BC) thresholds were lower in Group 1 than in the control group but the difference was not significant. In Group 2, preoperative AC thresholds were significantly lower than in the control group (p < 0.05). BC thresholds were also lower in Group 2 than in the control group and the difference was significant (p < 0.05). As a result of this study, we assume that there may be a relationship between bone level thresholds and the radiological extension of otosclerosis within the otic capsule.

Adult↗
PubMed2001

Vestibular schwannomas: correlations between magnetic resonance imaging and histopathologic appearance.

BACKGROUND: The indication for surgery of vestibular schwannomas (VS) remains controversial and depends on several factors. The ability to predict their patterns of growth would allow better surgical planning. This growth may depend on tumoral proliferation but also depends on dystrophic changes. OBJECTIVE: The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in predicting the evolution of VS. For this purpose, the authors attempted (1) to compare the MRI appearance of VS with its histopathologic features, (2) to correlate the MRI appearance of VS and its histopathologic features with its size, and (3) to evaluate the index of proliferation (IP) of each VS. PATIENTS AND METHODS: Thirty VS were studied with MRI before surgery. The VS were measured and classified as homogeneous, heterogeneous, and cystic. After surgery, IP was evaluated with immunohistochemical study using MIB-1 monoclonal antibody, and compared with tumor size. Pathologic studies evaluated the prevalence of Antoni type A and type B tissue, the amount of fibrosis, and the presence of siderin-loaded macrophages, xanthomatous cells, and cysts. RESULTS: The IP was low (0.2%-2.2%) and was not correlated with VS size. On MRI, 13 VS were homogeneous, 12 heterogeneous, and 5 cystic. The 13 homogeneous VS were smaller and were predominantly made of Antoni type A tissue. The 12 heterogeneous and 5 cystic VS were larger and were predominantly made of Antoni type B/mixed tissue. Heterogeneous and cystic VS showed significantly more hemosiderin deposits. There was a significant relation between the amount of hemosiderin deposits and the mean size of VS. Microscopic cysts were observed only in VS with cystic MRI appearance. Fibrosis was present in all tumors regardless of their size and MRI appearance. CONCLUSION: A heterogeneous MRI aspect (correlated with larger mean size) not only is related to the ratio of type A to type B tissue but also is caused by other pathologic changes, mainly hemosiderin deposits and cystic formation. Increasing tumor size probably depends less on IP than on dystrophic changes (hemosiderin, cysts) and/or on the presence of type B tissue.

Adolescent↗
PubMed2001

Correlations between computed tomography findings and family history in otosclerotic patients.

BACKGROUND: Otosclerosis is a heritable disease affecting the otic capsule. Its genetics have been studied since the 19th century, but several issues remain controversial. OBJECTIVE: The goals of this study were to assess the prevalence of sporadic and familial forms of otosclerosis in a population of otosclerotic patients and to compare the radiologic findings between both groups. STUDY DESIGN AND SETTING: This retrospective study was conducted in a single institution. PATIENTS: This study included 211 patients operated on for otosclerosis. MAIN OUTCOME MEASURES: Clinical data, including pure tone audiograms, were available from patients' charts. A questionnaire assessing family history of otosclerosis and deafness was mailed to the otosclerotic patients. A relative was considered otosclerotic if surgery confirmed the disease. The family history was correlated with the computed tomography results. This examination was performed before surgery in all patients. RESULTS: A family history of otosclerosis was found in 24.2% of the patients. The radiologic findings differed between patients with a sporadic form of otosclerosis and those with a familial form. The lesions were more often detectable, bilateral, and severe in the familial forms (p < 0.05). CONCLUSION: These findings lead to the assumption that fenestral radiologic otosclerosis occurs more in sporadic forms, whereas more extensive lesions on computed tomography seem to indicate the familial forms. Hereditary forms demonstrated to be familial seem to lead to more severe disease. The search for a genome locus of otosclerosis may be enlightened by these findings.

Adult↗
PubMed2000

[Investigations and diagnosis of deafness].

Otoscopic examination and audiometric tests complement each other for the diagnosis of hearing loss. Objective tests measure the hearing loss at some specific frequencies. Endo- or retrocochlear origin of the deafness is identified thanks to these tests, leading to selection of the most appropriate therapeutic option. In children, behavioral assessment techniques are to be adapted to the patient's age. Information from tympanometry, otoacoustic emissions and possibly auditory brainstem responses, is used to complete the diagnosis. Language skills are also assessed in order to adapt the child's deafness management to his/her actual communication ability.

Acoustic Impedance Tests↗
PubMed2000

Benefits of cochlear implantation in elderly patients.

Cochlear implantation in elderly patients is a questionable subject. The purpose of this study was to evaluate the procedure and its outcome, the postoperative course, and the audiologic and social benefits of cochlear implantation in this population. Twenty-seven patients older than 60 years were compared with a control group of 15 adult patients. This retrospective study analyzed data concerning the outcome of the procedure, postoperative course, postoperative orthophonic test results, and answers of a questionnaire assessing the changes in communication, perception, and social outcomes. The procedure was uneventful in both groups. Minor complications were not more frequent in elderly patients. Orthophonic test results were comparable in both groups. At 12 months, 83% of the elderly patients had an open-set speech discrimination score above 60%. The benefits of cochlear implantation in terms of the quality of life are not statistically different with younger patients. Cost-utility analysis might support these findings.

Adult↗
PubMed2000

Pure sensorineural hearing loss and otosclerosis. An imaging case report.

Pure sensorineural hearing loss is not a rare finding in otological practice. Numerous aetiologies could be at the origin of such a deficit. However, otosclerosis is very rarely cited as a cause of pure sensorineural hearing loss. We present one such case of pure sensorineural hearing loss linked to otosclerosis in a 30-year old caucasian male and underline the high contribution of computed tomography to confirm such a diagnosis. Pure sensorineural hearing loss due to otosclerosis is a rare event and can be misdiagnosed. The clinical diagnosis of such a disease may be difficult. In these cases, CT-Scan is the exam of choice to confirm the diagnosis.

Adult↗
PubMed2000

Functional magnetic resonance imaging may avoid misdiagnosis of cochleovestibular nerve aplasia in congenital deafness.

OBJECTIVE: To investigate a narrow internal auditory canal (IAC) syndrome using functional magnetic resonance imaging (fMRI) of the auditory cortex. STUDY DESIGN: The study design was a case report. The follow-up period lasted 18 months. SETTING: The study was carried out in the audiology clinic of an ear, nose, and throat department and in the department of pediatric neuroradiology at a university hospital. MAIN OUTCOME MEASURES: Age-appropriate observational audiometry, objective audiovestibular tests, computed tomography (CT), magnetic resonance imaging (MRI), and (fMRI) of the auditory cortex were performed to analyze in detail the profound deafness of a young child. RESULTS: Audiovestibular examination demonstrated both measurable hearing and normal vestibulo-ocular reflex, and CT showed narrow IACs combined with normal labyrinths. Axial MR images completed by sagittal sections perpendicular to the IAC delineated a single nerve that was initially supposed to be the facial nerve. No cochleovestibular nerve was identified. However, fMRI performed with the patient under general anesthesia demonstrated activation of the primary auditory cortex during 1-kHz monaural stimulation on the left side. CONCLUSIONS: The absence of cochleovestibular nerve on MR studies cannot exclude connections between the inner ear and the central auditory pathways. This might be caused by a lack of spatial resolution of anatomical MR studies. The single nerve delineated within the IAC might also carry both facial and cochleovestibular fibers. Functional MRI can assess the cortical response to acoustic stimuli when aplasia of the cochleovestibular nerve is suspected. This case study illustrates a novel and atypical presentation of cochlear nerve dysplasia.

Acoustic Stimulation↗
PubMed2000

Effectiveness of conservative management of acoustic neuromas.

OBJECTIVE: The goal of this study was to assess the effectiveness of the conservative management in patients with acoustic neuroma (vestibular schwannoma). STUDY DESIGN: This retrospective study was performed in a university hospital. PATIENTS: Patients were selected for this wait-and-see policy on the basis of age, general condition, audiometric results, tumor size, and patient preference. The study group included 97 patients, 87 of whom had at least two neuroradiologic examinations. The mean age of this population was 63 years (29 to 89 years). The mean length of follow-up of this population was 31 months. Eighty-seven of these patients had at least two radiologic examinations (magnetic resonance imaging or computed tomography). The mean interval between the initial and follow-up radiologic examinations was 15 months. MAIN OUTCOME MEASURES: Tumor size was measured by use of two-dimensional data in all patients. The mean tumor size was 12 mm. The growth rate of the tumor was estimated by comparison of the results of the measurements from the initial and follow-up neuroradiologic examinations. RESULTS: Of the 97 patients studied, 6 patients required surgery and 6 required radiotherapy. Sixty patients (62%) were still being treated conservatively at the end of the study period. Three patients of 28 who were classified as candidates for hearing preservation surgery lost their candidacy during the observation period. The mean annual tumor growth rate was 1.52 mm/year. The tumor was stable in size in 36% of patients, regressed in 11% of patients, or grew in 53% of patients. The growth patterns of the acoustic neuroma fell into five categories: continuous growth in 15% of patients, negative growth in 5%, growth followed by negative growth in 40%, negative growth followed by growth in 20%, and no variation of tumor size in 20%. CONCLUSION: Conservative management of acoustic neuromas carries difficulties: long-term follow-up of the patients and unpredictability of the tumor growth pattern. A reliable and reproducible radiologic method for evaluating tumor size is of great importance.

Adult↗
PubMed1999

Relationship between cochleovestibular disorders in hemifacial spasm and neurovascular compression.

OBJECTIVE: To investigate the evolution of cochleovestibular symptoms before, during, and after microvascular decompression (MVD) of the facial nerve in hemifacial spasm. STUDY DESIGN: Prospective study in patients with hemifacial spasm. Among our 13 patients who underwent MVD of the facial nerve from 1995 to 1997, 6 had associated cochleovestibular disorders confirmed by neurotologic tests. RESULTS: In four of these patients, a concomitant compression of the eighth and facial nerves was found at surgery. Preoperative magnetic resonance angiography studies had shown three cases of this double neurovascular compression. Intraoperative auditory brainstem response monitoring showed that interposition of Teflon between vessel and facial nerve was highly critical to the auditory function. Auditory brainstem response monitoring was used to guide the surgeon during this critical phase. Surgery improved at least one cochleovestibular symptom in each patient. CONCLUSIONS: The authors propose two pathophysiologic hypotheses. First, the concomitant facial and cochleo-vestibular symptoms may be due to a hyperactivity of both the facial and vestibular nuclei. According to theories about cryptogenic hemifacial spasm, the origin of this hyperactivity could be an ectopic excitation focus. However, the two nerves may have different sites of ectopic excitation. According to the second hypothesis, a pulsatile compression of the facial nerve may be transmitted to the eighth nerve. This could take place even if only the facial nerve is in contact with a vascular loop.

Aged↗
PubMed1999

[Preoperative evaluation of translabyrinthine cholesteatomas by MRI].

PURPOSE: Hearing preservation is one of the major goals of surgical resection of invasive cholesteatomas. Patients were prospectively evaluated using a 3D-CISS MR acquisition in order to improve the detection of perilymphatic fistulae. MATERIALS AND METHODS: 16 patients (10 M, 6 F) presenting with a primary (1 case) or a secondary (post-otitis) middle ear cholesteatoma extending to the osseous labyrinth (as defined by HR-CT) were evaluated at MR (1.5 T Vision, Siemens). The 3D-CISS sequence (TR: 12.25 ms, TE: 5.90 ms, flip angle: 70 degrees, slice thickness: 1 mm, matrix: 307 x 512, FOV: 200) allowed detection of invasion of the membranous labyrinth using a 3 level grading scale: 1) normal fluids, 2) focal and 3) diffuse obliteration of labyrinthine fluid. RESULTS: While CT showed a definite osseous labyrinthine fistula, the 3D-CISS sequence depicted either a normal membranous labyrinth (9 cases), a focal obliteration of the basal turn (1 case) or lateral semi-circular canal (3 cases) or a diffuse obliteration of the labyrinthine fluid (3 cases). Diffuse obliteration of the labyrinth fluid and 1 out 3 cases of focal obliteration of the semi-circular canal were found to have perilymphatic fistulae at surgery. None of the normal labyrinths were associated with perilymphatic fistula formation. CONCLUSION: The 3D-CISS sequence allows a comprehensive preoperative evaluation of the membranous labyrinth. Loss of signal from the labyrinthine fluid due to invasion or compression of the membranous structures accounts for the lack of specificity of the technique.

Adult↗
PubMed1998

Pre-operative and per-operative factors conditioning long-term facial nerve function in vestibular schwannoma surgery through translabyrinthine approach.

Facial nerve function was evaluated in 103 patients, after vestibular schwannoma removal through the translabyrinthine approach. The mean follow-up was 43 months (minimum six months). Grade I facial function was achieved in 100 per cent of stage I schwannomata compared with 36 per cent of stage IV schwannomata. Grade I or II facial function was found in 78 per cent of homogeneous schwannomata, compared with 48 per cent of heterogeneous schwannomata. Facial function was preserved in 89 per cent of cases, if the angle between the internal auditory canal and the schwannoma was > 66 degrees, compared with 54 per cent if the angle was < 66 degrees. There was 82 per cent of normal facial function when the nerve appeared normal after tumour removal, compared with 18 per cent when the nerve was traumatized. When the ratio (stimulation threshold at the internal auditory canal/stimulation threshold at brainstem) was < 2, post-operative facial function was preserved in 87 per cent of cases, compared with 13 per cent when the ratio was > 2.

Adolescent↗
PubMed1998

Does intrathecal morphine in the treatment of cancer pain induce the development of tolerance?

OBJECTIVE: This retrospective study was designed to investigate whether chronic lumbar intrathecal administration of morphine leads to the development of opioid tolerance in patients suffering from intractable cancer pain. METHODS: Between 1978 and 1995, 159 patients with refractory cancer pain were treated with intrathecal morphine in our Multidisciplinary Pain Center. The treatment consisted of preservative-free morphine administered through an access port as a single bolus. In this series of patients (n = 159), the daily doses of intrathecal morphine were determined as a function of duration of follow-up. RESULTS: The mean follow-up period was 95 days (range, 5-909 d), the mean starting daily dose of intrathecal morphine was 2.69 mg (range, 1-7.5 mg), and the mean terminal dose was 7.82 mg (range, 1-80 mg). The results demonstrated that only a moderate increase in daily dose of intrathecal morphine was required during the course of treatment (a two- to threefold increase for a 3-mo period). Furthermore, the dose increment was similar for patients followed up for more or less than 60 days. This increase did not result in any central opioid-related side effects, and the pain was managed satisfactorily. CONCLUSION: The requirement for a moderate increase in intrathecal opioid doses reflects the development of tolerance but did not limit the patients' ability to obtain adequate analgesia during the course of their painful disease.

Adult↗
PubMed1998

[Cochleovestibular disorders associated with hemifacial spasm: an outcome after microvascular decompression of the facial nerve].

Twelve patients underwent microvascular decompression by retrosigmoid approach to relieve severe hemifacial spasm. The surgery was done under intraoperative monitoring of the auditory function. Assessment at Day 2, Day 10, 2 months and 6 months after the operation found that the surgery had resulted in 9 recoveries, 3 improvements and 1 failure. Brain stem auditory evoked potentials monitoring showed that the interposition of Teflon between the vascular loop and the facial nerve is a critical stage for the auditory function. Six of the twelve patients were also complaining of cochleo-vestibular disorders: vertigo and tinnitus, or hearing loss and tinnitus, or vertigo alone. The surgery improved at least one of these cochleo-vestibular symptoms in each one of the patients. There was one hearing improvement, vertigo disappeared in three cases out of four, and tinnitus disappeared in four cases out of five. The possibility of a concomitant compression of cochleo-vestibular and facial nerve was investigated using cochleovestibular tests, radiological data and intra-operative findings.

Aged↗
PubMed1997

Selection criteria for cochlear implants in children.

OBJECTIVE: To determine the selection criteria for cochlear implantation in children. SETTING: Hospital pediatric implant center. PATIENTS AND INTERVENTIONS: Selection of patients depends on medical evaluation, audiometric data, speech discrimination, communication skills, cognitive skills, and psychosocial factors. Patient selection is based on tonal audiometry, computed tomography, magnetic resonance imaging, and electrophysiologic tests. Side of implantation is chosen according to cochlear structure, duration of deafness, and dominant handedness. RESULTS: Ninety-eight cochlear implantations with the Nucleus multichannel implant have been performed at this center since 1990. CONCLUSION: The selection of children for cochlear implantation require close collaboration between the pediatric surgical team, the educational team, and the family.

Auditory Threshold↗
PubMed1997

[Cochlear implants in the elderly].

The authors present a retrospective and multicenter study of 18 elderly patients aged above 60 years-old who underwent a cochlear implantation by comparing them with a population of adult patients. The purpose of this study is to evaluate the utility and benefits of cochlear implantation in the elderly by analyzing the clinical data and the results of a questionnaire assessing the use of the implant and the consequences of implantation on the quality of life. The results of this study indicate that the improvement of quality of life in the elderly is similar compared to a control group of adult patients.

Aged↗
PubMed1997

[Conservation of residual hearing after cochlear implantation].

Indications for cochlear implantation have been expanded to include severely hearing impaired adults and may increase the number of patients presenting with preoperative residual hearing. Conservation of residual hearing may allow better performance with an implant. However, conventional thought is that implantation destroys auditory structures involved in residual hearing. This study was undertaken to assess if there are general or surgical factors intervening in the conservation of residual hearing in a sample of multichannel implant recipients. A retrospective study on 50 adult cochlear recipients with preoperative residual hearing has been undertaken. Sixteen of 50 implanted subjects (32%) were found to have conserved their residual hearing. Among them, seven patients have clinically non-significant changes of hearing. Age, side of implantation, gender and etiology did not influence the outcome of residual hearing. Round window ossification, ossification of the cochlea, length of insertion, approach and site of insertion (scala tympani vs.scala vestibuli) were not found to be statistically significant between the population having lost and the population having conserved residual hearing. This study emphasizes the need to undertake a larger multicenter longitudinal study to determine the existence of factors related to the conservation of residual hearing.

Adolescent↗
PubMed1996

Prenatal lesioning of vestibular organ by aminoglycosides.

The effects of gentamicin administrated to gravid mice on the vestibular hair cells of their offspring were investigated. Scanning electron microscopy showed the effect to be dose-dependent and age-dependent, and there was a different sensitivity to toxicity for each of the three types of vestibular receptors. The destructive action of gentamicin on the vestibule before birth provides a mechanism to study the influence of the vestibular system on the central nervous system throughout its development.

Aminoglycosides↗