Radiology quiz case 2. Blindness secondary to nasal polyposis.
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Blindness↗
Biomedical subjects
Rafael Ramírez-Camacho
Publications and source records attributed to Rafael Ramírez-Camacho.
Enlarged vestibular aqueduct: Looking for genotypic-phenotypic correlations.
The aim of this work is to provide a guide for clinical and genetic diagnosis and classification of the enlarged vestibular aqueduct syndrome based on a review of the literature and computerized databases with the words large and enlarged vestibular aqueduct. No more than 40 articles described association between the EVA phenotype and a known genetic alteration. Pendred's syndrome, distal renal tubular acidosis, waardenburg's syndrome, X-linked congenital mixed deafness, branchio-oto-renal syndrome, and oto-facio-cervical syndrome can express their genotypic alteration as enlarged vestibular aqueduct syndrome. We also found articles reporting familiar cases of enlarged vestibular aqueduct with no identified mutations in studied genes.
Genotype↗
Alternatives to systemic steroid therapy for refractory immune-mediated inner ear disease: A physiopathologic approach.
Immune-mediated inner ear disease (IMIED) is one of the few forms of reversible sensorineural hearing loss. Corticosteroids-responsive patients are usually associated with hearing improvement. Due to the long clinical course of IMIED that frequently present recurrences (hearing loss and vertigo), alternatives to corticosteroids such as methotrexate and recently TNF-alpha blockers have been proposed. Likewise new procedures for delivering corticosteroids to the inner ear have been developed. The aim of this article is to assess the efficacy of methotrexate and transtympanic 6-methylprednisolone in refractory IMIED. From a database of 200 patients affected by IMIED, 16 selected patients with refractory disease were included in the present study. Five patients were treated with methotrexate and 11 by means of transtympanic injection of 6-methylprednisolone. All patients treated with methotrexate had an improvement in their vestibular symptoms. However, hearing loss did not improve. Most patients treated with local 6-methylprednisolone (68.75%) showed an improvement in hearing loss and vestibular symptoms. Methotrexate has been shown to be ineffective in maintaining long-term remissions of hearing relapses although patients presented an improvement in vestibular symptoms. However, transtympanic 6-methylprednisolone has been shown to be a safe, easy and useful therapy in refractory IMIED and it may actually become the first-line treatment for these patients based on the existence of glucocorticoid receptors and the possible targets of immune-mediated damage within the inner ear.
Administration, Oral↗
TNFalpha blockers do not improve the hearing recovery obtained with glucocorticoid therapy in an autoimmune experimental labyrinthitis.
The effectiveness of etanercept [tumour necrosis factor-alpha (TNFalpha) blocker] and corticoids in treating immuno-mediated inner ear disease (IMIED) was compared in an animal model of autoimmune labyrinthitis. IMIED is one of the few forms of sensorineural hearing loss that is reversible with proper medical treatment. While the effectiveness and usefulness of immunomodulating agents (corticosteroids) in treating IMIED have been demonstrated, TNFalpha antagonists, which inhibit granuloma formation in rheumatoid arthritis and other autoimmune diseases, have been considered as an alternative therapy. The efficacy of etanercept (anti-TNFalpha) was evaluated in a guinea pig model of experimental autoimmune labyrinthitis in which 25 guinea pigs were divided in a control group, which was used to document the rise in hearing thresholds following immunisation, and two experimental groups, which were treated with steroids (6-methylprednisolone) and anti-TNFalpha (etanercept), respectively, after the immunisation. Comparison of the auditory thresholds obtained by means of auditory brainstem response (ABR) revealed that the auditory thresholds of the two experimental groups were not statistically different (6-methylprednisolone: 41.5 dB, SD: 8.51; etanercept: 37.5 dB, SD: 7.91) and that both compared favourably with that of the control group (60 dB, SD: 7.91) at p=0.001. We therefore conclude that etanercept is as effective as glucocorticoids in an animal model of autoimmune labyrinthitis; however, the potential adverse effects and high price of the former advise against its use as an initial therapy for IMIED.
Analysis of Variance↗
Spontaneous otitis media in Wistar rats: an overlooked pathology in otological research.
The rat is commonly employed in otological research, but spontaneous ear infections can confound the results of experimental procedures--wasting time, money, and animals. The authors focus on the incidence of spontaneous otitis media in Wistar rats. They compare disease incidence in animals housed in standard cages with those housed in barrier units, showing that 20% of their conventionally housed animals developed spontaneous otitis media, whereas only 5% of their animals housed in isolated units were infected. These results underscore the importance of strict control of the shipping, housing conditions, and manipulation of animals to be used in otological research.
Animal Husbandry↗
Anti-adhesive properties of polytetrafluoroethylene (Gore-Tex) in middle ear surgery. An experimental study.
CONCLUSIONS: Polytetrafluoroethylene (PTFE) may represent a material that prevents adhesions when implanted in the middle ear. This characteristic can be used to improve the design of prostheses. OBJECTIVE: Prostheses in the middle ear have a relatively high failure rate due to extrusion, deformation and adhesion. Adhesion of prostheses to the walls of the tympanic cavity is the commonest cause of long-term hearing loss. The anti-adhesive properties of PTFE have been previously studied in abdominal and vascular surgery. To the best of our knowledge, this is the first work in which the properties of PTFE have been studied in the context of middle ear pathology. MATERIAL AND METHODS: In order to induce otitis media with effusion, 27 Wistar rats underwent a technique based on permanent cauterization of the pharyngeal Eustachian tube. PTFE was subsequently implanted in the middle ear. Rats that underwent cauterization without implantation and cauterization with implantation of hydroxyapatite and Plastipore were included as controls. RESULTS: Histopathological study of the tympanic bullae at 15 and 90 days after implantation demonstrated good biocompatibility of the PTFE implant under the analyzed conditions, with formation of a capsule around the material and no adhesions between the ear tissues and the prosthesis.
Acoustic Impedance Tests↗
Otosyphilis mimics immune disorders of the inner ear.
Syphilis is a well established cause of hearing loss. Sensorineural hearing loss may develop in the congenital or acquired form. The clinical course of the early acquired and late congenital forms are similar: sudden or rapidly progressive bilateral sensorineural hearing loss with mild vestibular symptoms. Cochleovestibular involvement in early acquired syphilis has been related to a basilar meningitis with lymphocytic infiltration of the labyrinth and VIIIth nerve. However, neurosyphilis and inner ear syphilis are not the same disease. Prompt diagnosis and treatment with corticosteroids and penicillin are mandatory to reduce the immune response and fibrosis of the labyrinth and the endolymphatic sac. Unfortunately, early acquired syphilis is frequently overlooked in the differential diagnosis of other forms of sensorineural hearing loss, particularly autoimmune inner ear disease. Given the increasing number of luetic infection cases, especially in immunocompromised patients, this condition should be considered in any sexually active patients affected by sudden hearing loss. Cases of inner ear syphilis are presented. Immunopathology of luetic inner ear infection is discussed and compared with immune disorders of the inner ear.
Adolescent↗
Ageing evokes an intrinsic pro-apoptotic signalling pathway in rat cochlea.
CONCLUSIONS: These findings support the hypothesis that age-related apoptosis evokes an intrinsic pathway of pro-apoptotic signalling within the rat cochlea. OBJECTIVES: The aim of this study was to explore the effects of ageing on cochlear apoptosis in rats, as well as the different signalling pathways involved. MATERIALS AND METHODS: Female Sprague Dawley rats of different ages were used (mean age 7.72+/-1.93 months, n=100). Luciferase assays were used to determine the different caspase activities and ATP levels in rat cochlear protein extracts. Protein and gene expression was examined by Western blotting and real-time RT-PCR assays, respectively. RESULTS: Caspase-3/7 activity, as well as caspase-3 gene expression, were statistically higher in early-mature rats (EM, 276,139+/-13 669 RLUs (relative light units), p<0.001; and 390+/-50 arbitrary units, p=0.0017, respectively) or in aged-mature rats (AM, 371,020+/-26,457, p<0.0001; and 1510+/-90, p<0.0001, respectively) than younger rats (YR 147,129+/-8485 and 0.14+/-0.004, respectively). An increased caspase-9 activity with ageing was also observed (YR 49,932+/-2046 RLUs vs EM 260,890+/-5939, p<0.0001 or AM 118,241+/-12,423, p<0.0001). Caspase-8 activity was not affected significantly by age. Bax protein expression also increased by age (YR 38,200+/-1790 arbitrary units vs EM 76,549+/-5450, p<0.05), in contrast to Bcl-xL protein expression (YR 27,000+/-5000 arbitrary units vs EM 10,200+/-5000, p<0.005).
Aging↗
Radiology quiz case 4. McCune-Albright syndrome.
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Adult↗
Pseudomonas aeruginosa infection in the hypoventilated middle ear: an experimental model.
CONCLUSION: This is a suitable model for studying different aspects of the pathophysiology of chronic suppurative otitis media. OBJECTIVE: To analyze the methodological features of an animal model of chronic suppurative otitis media induced by intratympanic inoculation of Pseudomonas aeruginosa. MATERIAL AND METHODS: Otitis media was induced by inoculation of P. aeruginosa through the inferior aspect of the rat bulla and cauterization of the Eustachian tube via a transpalatal approach. Inspection of the tympanic membrane, culturing of middle ear effusion and processing of the temporal bones for light microscopy were performed. RESULTS: Abnormal otomicroscopic findings and persistence of infection were correlated with the histopathological changes found in middle ear tissues.
Animals↗
Immunologic work-up study for inner ear disorders: looking for a rational strategy.
CONCLUSIONS: For the evaluation of a patient with suspected immune-mediated inner ear disease (IMIED), an exhaustive immunologic work-up study is not recommended if financial resources are limited. Analysis of antinuclear antibodies (ANA) and the immunophenotype of peripheral blood lymphocytes (PBL) proved to be the most useful tests in our population to support the clinical diagnosis of IMIED. OBJECTIVE: Owing to the lack of specific serological markers for the diagnosis of IMIED, an exhaustive immunologic work-up study for patients with suspected IMIED is usually performed. The aim of this study was to estimate the use of resources and the costs involved in the routine laboratory tests used for the diagnosis of IMIED. MATERIAL AND METHODS: This was a comparative study of two groups of patients with a high suspicion of diverse clinical forms of IMIED who were subjected to different serologic test designs. The cost of the classical immunologic work-up study used for the diagnosis of IMIED (n=125) was estimated in comparison with that of a more restricted examination, based on a recently reported high-risk profile, involving the analysis of ANA and PBL (n=57). RESULTS: The diagnostic efficiency of the two protocols was similar. The cost of a complete immunologic work-up study was 241.77 euros and that of the limited analysis was 53.12 euros.
Adolescent↗
Supporting cells as a target of cisplatin-induced inner ear damage: therapeutic implications.
OBJECTIVES/HYPOTHESIS: Cisplatin induces adverse effects such as ototoxicity and nephrotoxicity. Unexplained hearing improvement in sudden deafness and fluctuating hearing loss suggests the presence of some mechanisms other than the primary lesion of the outer hair cell. The authors' aim was to study the functional and morphological lesions induced in the cochlea of the rat after cisplatin injection. STUDY DESIGN: Prospective experimental morphological and functional study. METHODS: Forty-eight Wistar rats were given intraperitoneal injections of 5 mg/kg cisplatin. After short-, medium-, and long-term survival, animals were studied by means of auditory brainstem response testing and scanning electronic microscopy. RESULTS: An increased hearing loss was observed in animals with long-term survival compared with animals with short-term survival after a single dose of cisplatin. These findings correlated with a more intense injury of the supporting cells, continuing with the late deterioration of the hair cells. CONCLUSION: The study suggested that the initial damage of the supporting cells could be responsible for the late injury of the hair cells. This hypothesis was supported by the late increase in hearing loss after a single dose of cisplatin, emphasizing the role of the supporting cells in the cochlear changes induced by cisplatin.
Animals↗
Controversies and criticisms on designs for experimental autoimmune labyrinthitis.
Although immune-mediated inner ear disease was reported around 25 years ago, numerous attempts to identify the inner ear antigens have been performed. Experimental animal models have been used to study the immune mechanisms involved in hearing loss and to develop new therapies. Because animal models of autoimmune labyrinthitis have been developed by means of different antigens, we cannot yet show a valid immunopathologic explanation. A critical analysis of the more relevant experimental models employed has been performed in order to validate the methodology. Comparison between these models and animals with spontaneous systemic autoimmune disease has raised more questions concerning the pathophysiology of autoimmune hearing loss. A new pathogenetic theory is suggested, involving the supporting cells of the organ of Corti.
Animals↗
Sudden presentation of immune-mediated inner ear disease: characterization and acceptance of a cochleovestibular dysfunction.
Since the McCabe report, growing indirect evidence has accumulated to indicate the implication of immune mechanisms in the pathogenesis of immune-mediated inner-ear disease (IMIED). A clinical study of a group of patients affected by this condition was performed in order to characterize the immune group, based on a recently reported profile, and compared with the vascular, viral and idiopathic aetiologies of sudden deafness. Patients affected by immune-mediated inner-ear disease had the best and the earliest recovery rate of hearing (p = 0.0028 and p = 0.017, respectively). However, this group of patients also had the higher rate of recurrence (p = 0.034), supporting the typical clinical course of the autoimmune disorders. On the basis of the results the criteria used in the diagnosis of the sudden presentation of the immune-mediated inner ear disease could be accepted leading to the characterization of this condition. Likewise, the role of the supporting cells in the pathogenesis of the IMIED is discussed.
Adolescent↗
Validity of the Western blot immunoassay for heat shock protein-70 in associated and isolated immunorelated inner ear disease.
OBJECTIVE: To assess the validity of the Western blot immunoassay for heat shock protein-70 (hsp-70) for diagnosis of autoimmune inner ear disease. STUDY DESIGN: Retrospective study of 53 patients affected by sudden deafness (n = 19), idiopathic progressive sensorineural hearing loss (n = 24), and Meniere's disease (n = 10) who were treated from 1995 to 1999. The clinical course and response to corticosteroid were evaluated. METHODS: A purified hsp-70 antigen from bovine kidney cell line was used for the Western blot immunoassay. RESULTS: Only five patients (9.4%) showed anti--hsp-70 antibodies: Two presented a sudden sensorineural hearing loss (sudden deafness group), two showed an idiopathic progressive sensorineural hearing loss (idiopathic progressive sensorineural hearing loss group), and one was affected by fluctuating hearing loss (Meniere's disease group). A systemic autoimmune condition was observed in 29.1% of patients with idiopathic progressive sensorineural hearing loss. CONCLUSIONS: The low sensitivity of Western blot immunoassay for patients affected by idiopathic progressive sensorineural hearing loss and Meniere's disease may result from either the long time elapsed from the hearing loss and vertigo to the initial examination or from the increased percentage of cases of systemic autoimmune disease present in patients with idiopathic progressive sensorineural hearing loss. More studies to detect the immune-mediated inner ear disease in Western blot immunoassay-negative patients are required.
Adrenal Cortex Hormones↗
Sudden sensorineural hearing loss: supporting the immunologic theory.
Sudden deafness constitutes a diagnostic challenge. Classically, 2 causes, viral and vascular, are considered in the origin of idiopathic sudden hearing loss. More recently added to the list of possibilities are rupture of the membranous labyrinth and immune-mediated sensorineural hearing loss. The latter can be either primary and localized to the inner ear or, in perhaps fewer than one third of cases, secondary to generalized systemic autoimmune disease. The purpose of the present review is to define immune-mediated sudden sensorineural hearing loss as a distinctive entity, on the basis of clinical, immunologic, and pathological findings, and suggest a profile of the typical patient.
Adrenal Cortex Hormones↗
Labyrinthitis secondary to experimental otitis media.
PURPOSE: Analysis of labyrinthitis in a model of otitis media. MATERIALS AND METHODS: Morphologic study in 20 Wistar rats in which otitis media was induced by transbullar inoculation of Pseudomonas aeruginosa with obstruction of the eustachian tube. RESULTS: Seventy percent of rats showed vestibular signs. Histologic changes ranged from nonaffected labyrinths to suppurative labyrinthitis. CONCLUSIONS: Dissemination of infection probably occurs through round window membrane. A thinner round window membrane typical of rodents would be the reason for a more severe clinical and morphologic picture in rats when compared to human beings.
Animals↗
Familial isolated unilateral large vestibular aqueduct syndrome.
Large vestibular aqueduct syndrome (LVAS) is one of the most frequent inner ear malformations. It is associated with varying degrees of hearing loss, that may be progressive, sudden or fluctuant; nevertheless normal hearing in cases with LVAS has been described. Although unilateral LVAS has been described, all patients show clinical and radiological findings in both ears, in contrast to the family presented here, where 2 siblings are affected by unilateral sensorineural hearing loss associated with ipsilateral LVAS, with an autosomal recessive pattern. In order to search for the origin of this inner ear malformation, mutations in genes GJB2 (connexin-26 gene), PDS (Pendred's syndrome gene) and mitochondrial 12sRNA were studied, without positive results. In this paper we hypothesize the probable embryological origin for this malformation.
Adolescent↗