SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Sudden hearing loss is a symptom caused by a variety of diseases, among them also a perilymph fistula. The occurrence of bilateral perilymph fistula is rare, and was reported only associated with head trauma. A case of a bilateral perilymph fistula, without head trauma in an adult construction worker is reported. To the best of our knowledge this is the first bilateral case caused by physical effort to be reported in the literature.
Inquire into the mechanism of inner ear pathological physiology in autoimmune sensorineural hearing loss (ASHL). With the auditory electric-physiological techniques and enzyme-histochemical method, the change of inner ear hearing function and enzyme activity were observed. These animals, which threshold of auditory nerve compound active potential (CAP) and cochlear microphonic potential(CM) heightening evidently, showed that the amplitude of endolymphatic potential(EP) (include-EP) bring down in various degrees, which was related to the change of the active of Na(+)-K(+)-ATPase and SDH in vascularis stria and endolymphatic sac. The abnormality of enzymes metabolism in inner ear tissues, which following autoimmune inflammation damage, is the pathological foundation of hearing dysfunction.
We examined the electrocochleography (ECochG) parameters in patients suffering from Meniere's disease (n = 5) or other type of vertiginous disorder (n = 4). Fourteen ears were examined by introducing a needle electrode through the tympanic membrane to the promontorium. The summating potential (SP), action potential (AP) and the SP/AP ratio were measured from the alternating polarity click response, and the latency difference from the condensation and rarefaction click responses. These 2 patient groups differed from each other most clearly as to the audiometry results and the duration of symptoms. We also found differences in electrocochleographic results, especially in latency differences between the condensation and rarefaction click responses. Although the present material is small we conclude that transtympanic electrocochleography is a sensitive method to measure cochlear potentials, and might be a valuable addition in diagnosing patients suffering from various cochleovestibular disorders.
Both the guinea pig and squirrel monkey were used in this study. An animal model for inner ear disease was established, and each animal was subjected to vestibular function tests consisting of spontaneous nystagmus recording, positional testing, caloric testing, and optokinetic stimulation testing. Recordings of nystagmus in the guinea pig and squirrel monkey were successfully obtained by using newly devised clip electrodes. A variety of nystagmic patterns in animal models following experimentally created perilymphatic fistula and labyrinthectomy are presented in this study.
Nine patients are presented who underwent cochlear implantation in the presence of chronic suppurative otitis media. Four had a simple tympanic membrane perforation, four had a pre-existing mastoid cavity and one had cholesteatoma in the ear chosen for implantation. Patients with a simple perforation had a staged procedure with myringoplasty followed by cochlear implantation after an interval of three months. Patients with cholesteatoma or with an unstable mastoid cavity were also staged. A mastoidectomy or revision mastoidectomy was performed with obliteration of the middle ear and mastoid using a superiorly pedicled temporalis muscle flap and blind sac closure of the external meatal skin. After a further six months a second stage procedure was performed to confirm that the middle-ear cleft was healthy and to insert the implant. Patients presenting with a stable mastoid cavity underwent obliteration of the cavity and implantation of the electrode as a one-staged procedure. To date there have been no serious problems such as graft breakdown, recurrence of disease or implant extrusion, and all patients are performing well.
The purpose of this paper is to provide performance data on long-term congenitally and prelingually deafened children and adults who are implanted with the CLARION Multi-Strategy Cochlear Implant and who use the Continuous Interleaved Sampler (CIS) speech processing strategy. Open-set speech perception was assessed preoperatively and postoperatively with word and sentence recognition tests. Results indicate that a majority of subjects showed improvement from preoperative performance to the last available postoperative evaluation. These results represent a change from previously reported data on a similar population who used earlier speech processing strategies.
Guinea pigs were immunized with human type I, type II or type III collagen. Inner ear lesions were induced in some guinea pigs by immunizing them with human type II collagen. Histopathologic changes included endolymphatic hydrops, organ of Corti lesions and endolymphatic duct contained a large number of inflammatory cells. These histologic changes resembled those observed in patient with Meniere's disease. We didn't discover any inner ear lesions in guinea pigs by immunizing them with human type I and type III collagen, although their serum antibody titers were high and antibody presented in perilymph. Immunohistochemical study showed the presence of type II collagen in the cochlea tissues--spiral ligament, basilar membrane, tectorial membrane, spiral limb and Rosenthal's canal. We didn't discover type I and type III collagen in these area.
Obliteration of old mastoids and wet middle ears with autologous abdominal fat seems to be a reliable technique to render chronically discharging mastoid cavities or open middle ears dry and closed. This paper is the third in the series and looks at the intermediate results at five years. Of the 16 patients (one bilateral) 94.1 per cent of the ears are still dry and uninfected with closed external meati. Recurrent cholesteatoma was found in two patients at implantation and removed.
Relapsing polychondritis is a rare disease probably of auto-immune etiology comprising inflammatory involvement of cartilage as well as phenomena of vasculitis. ENT manifestations are frequent and the authors present a case involving chondritis of the auricle, the nasal septum and affecting the cochleo-vestibular system as well. The diagnosis is based on the evocative clinical picture and on histological confirmation. Treatment consists of corticosteroids and immunosuppressive agents.
Camurati-Engelmann disease (CED, MIM # 131300) was diagnosed in a 27-year-old woman, who had pain in her lower legs. There was no history of hearing loss (or CED) in her family. She had been suffering from progressive hearing impairment since childhood. Serial audiograms demonstrated progressive mixed hearing loss from the age of 11 years onwards, for which she underwent successful stapes surgery bilaterally at the age of 13-18 years. Clinical ('juvenile') otosclerosis was found with stapes footplate fixation. Unfortunately, the sensorineural hearing loss component proved to be progressive bilaterally after surgery. At the age of 30 years, she experienced more rapid deterioration of her hearing loss in the right ear and episodes of vertigo. Vestibular examinations demonstrated progressive vestibular impairment 'otospongiotic' lesions with encroachment on the cochlear and vestibular labyrinth were found on high resolution CT scans at the age of 40 years; the internal auditory canal was normal bilaterally. CED may have formed a chance combination with juvenile otosclerosis in our patient, or otosclerosis may be part of the CED phenotype.
Chronic suppurative otitis media (CSOM) in profoundly deaf patients is a contraindication for cochlear implantation. Eight (6%) of the 126 patients referred to cochlear implantation at this center between 1986 and 1992 became deafened as a result of bilateral CSOM but were otherwise suitable candidates. This study details the methods used in four patients to prepare the septic ear for a sterile device. Two patients had wet radical cavities with residual cholesteatoma, and two had discharging safe perforations resistant to surgical repair. Obliteration of the middle ear cleft with blind pit closure of the ear canal was attempted in all four patients, and cochlear implants were installed at a second operation 3 to 6 months later. The hearing results were as good as in implanted patients without CSOM, and the only complication has been the finding of a cholesteatoma pearl at the second operation in one patient. Fat obliteration of the mastoid and middle ear with blind pit closure of the ear canal can be adapted to make most chronic ears fit for implantation, if the patient is prepared to undergo two operations.
Research suggests that duration of deafness prior to cochlear implantation affects postoperative speech recognition in adults. Duration of deafness usually is defined as the number of years between the onset of profound deafness and implantation. The purpose of this study was to examine the effects of duration of deafness--expressed as percentage of life with deafness--independent of age at implantation on postoperative speech recognition in adult postlingually deafened CLARION Multi-Strategy Cochlear Implant users. Speech recognition tests (CID sentences and NU6 words) were administered to 202 consecutively implanted adults preoperatively and at 3 and 6 months after initial device fitting. Patients implanted at a younger age and those with smaller percentages of their lives with deafness achieved the highest levels of short-term postoperative speech recognition. Patients who had been deaf for > or =60% of their lives demonstrated a slower rate of speech recognition improvement than those with shorter durations of deafness, but still continued to improve with increased implant experience.
The clinical course of Ménière's disease and the outcomes of functional examinations were found to be correlated, and a difference was found between the progressions of vestibular and cochlear dysfunction. Neither the total number of definitive vertiginous spells nor the duration of illness correlated significantly with the degree of audio-vestibular dysfunction. In contrast, frequent vertiginous spells were clearly associated with preservation of audio-vestibular function. Moreover, the clinical characteristics of those patients who experienced less than one definitive vertiginous spell per year were distinct from those of other patients, although both groups showed the typical symptoms of Ménière's disease.
Streptomycin perfusion of the labyrinth is the logical choice of treatment for the third stage of Meniere's disease with intractable vertigo. The results of streptomycin perfusion of the labyrinth are comparable to those of other treatments, including endolymphatic shunt and vestibular nerve section. Refinements must be made in the process of selecting candidates for the operation. To study the factors influencing the results of streptomycin perfusion of the labyrinth, 144 patients who had streptomycin perfusion of the labyrinth and were followed for 1 year were studied using the 1972 AAOO classification of results. The findings of this study indicate that only a low dosage of streptomycin and a small volume of perfusate are required to obtain good results. Patients who have long lasting severe endolymphatic hydrops with poor hearing preoperatively are less likely to achieve good results.
BACKGROUND: The article gives an overview of the most frequent forms of vertigo, that are of peripheral-labyrinthine, central-vestibular, psychogenic, or physiologic origin. Dizziness or vertigo is a result of a mismatch between 3 sensory systems: the vestibular, the visual, and the somatosensory systems. These systems are mutually interactive and redundant in that orientation and balance are guided by simultaneous reafferent cues. The functional ranges of the systems overlap, thus permitting them to compensate in part for each other's deficiencies. SUMMARY: Vertigo is not a well-defined disease entity, but rather a multisensory syndrome induced either by stimulation of the intact sensorimotor system by motion (eg, physiologic vertigo as in motion sickness or height vertigo), or by pathologic dysfunction of any of the stabilizing sensory systems (eg, peripheral vestibular as in vestibular neuritis, or central vestibular as in vertebro-basilar ischemia). The core region in vestibular vertigo syndromes is the vestibulo-ocular reflex, a 3-neuron arc that mediates the information of the semicircular canals and otoliths via the vestibular nerve and vestibular nucleus to the ocular motor nuclei (VI, IV, III) and the supranuclear integration centers in the ponto-mesencephalic brain stem. CONCLUSIONS: Clinical phenomena characteristic for physiological and pathologic vertigo syndromes include postural, perceptual, oculomotor, and vegetative syndromes, which manifest with ataxia, nystagmus, vertigo, and nausea. Thus, the clinical testing must include examinations of postural, perceptual, oculomotor, and vegetative dysfunctions.
In the mammalian cochlea neurotransmission between inner hair cells and afferent auditory neurons is probably mediated by glutamate or another related excitatory amino acid. Neurotoxicity induced by excessive glutamate release seems to play a crucial role in some pathological conditions of the cochlea, such as ischaemia or noise trauma. Thus, glutamate antagonists may be a new therapeutic strategy for different inner ear diseases. Because of their potential severe side-effects only a few glutamate antagonists have so far been adopted for clinical use. We used microiontophoretic techniques to compare the effects of memantine and caroverine on the glutamatergic transmission of inner hair cells of the guinea pig and tested the possibility of a local administration of memantine to the cochlea with a micropump. Memantine selectively inhibited the NMDA (N-methyl-D-aspartate) stimulated activity while caroverine blocked NMDA as well as AMPA (alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) induced activity of inner hair cell afferents. With a flow rate of 1 microl/h the local administration of memantine via a cochleotomy was succeeded in a reversible blockade of the spontaneous and the NMDA induced firing of inner hair cell afferents. These results suggest that local application to the cochlea could be a feasible way to administer glutamate antagonists in sufficient amounts while avoiding systemic side-effects.
OBJECTIVE: The classical technique for cochlear implantation (CI) involves mastoidectomy and posterior tympanotomy. The question raised in this work is whether mastoidectomy is indispensable in CI surgery. MATERIAL AND METHODS: The advantages and disadvantages of performing mastoidectomy during CI surgery were weighed, in particular the effect of mastoidectomy on chronic secretory otitis media (SOM) and the ability of the electrode to expand in the mastoid during skull growth. RESULTS: No effect of mastoidectomy on chronic SOM was found and the assumption that the electrode in the mastoid cavity has the ability to expand during skull growth was not proven. Eliminating mastoidectomy in CI surgery simplifies the procedure, shortens the duration of surgery, minimizes the amount of drilling and provides broader, better exposure of the middle ear and promontory. Mastoidectomy was found not to be obligatory in CI surgery and in fact may have more disadvantages than advantages. CONCLUSION: The development of alternative CT techniques which eliminate the need for mastoidectomy is justified.
Auditory brainstem response (ABR) is a good screening test for cerebellopontine angle (CPA) tumors and other retrocochlear diseases. The pathologic correlates of many cases with positive ABR remain unknown. A two-staged clinical study was performed to help us understand the significance of a false-positive ABR. In the first stage, data from 66 patients with abnormal ABR were reviewed. Nineteen patients had identifiable causes for the ABR abnormality, whereas 47 patients had no lesions identified. In the second phase of the study 21 of the 47 patients were re-evaluated with a minimum follow-up period of 1 year. A detailed interval history was obtained, and the work-up, including imaging studies, was repeated in an attempt to reach a diagnosis. One patient was found to have a CPA tumor, but for nine patients a definite final diagnosis could not be determined. The implications of abnormal ABR and normal initial imaging study are discussed, and a plan for the work-up of these patients is suggested.