1/178. Case report and discussion of hearing preservation after translabyrinthine excision of small acoustic tumors.OBJECTIVE: Since 1991, three separate reports have shown how hearing may be salvaged after translabyrinthine excision of small acoustic tumors. The authors submit yet another report of a complete translabyrinthine excision of a 1.4-cm intracanalicular acoustic tumor with modest hearing preservation. An attempt is made to retrace the steps of the operation and recognize and discuss what particular events may have safeguarded the viability of the cochlea. With the availability of cochlear implantation, there should be added incentive to preserve the cochlear neurones if hair cells cannot be saved. STUDY DESIGN: The study design was a retrospective case review. SETTING: The study was conducted at a primary care hospital. INTERVENTION: Therapeutic and rehabilitative measures were performed. MAIN OUTCOME MEASURES: Hearing preservation was measured. CASE REPORT: A 55-year-old woman presented with a left-sided hearing loss and a 1.4-cm left acoustic tumor completely filling the internal auditory canal (speech reception threshold [SRT] 30 dB, discrimination [Pb] 28%). A successful translabyrinthine excision of the tumor was performed in November 1995. A 1-year postoperative audiogram showed a mixed hearing loss in the left ear with SRT 85 dB and Pb 0%. Average pure-tone threshold for 500 Hz, 1 kHz, and 3 kHz was 50 dB and aided SRT 40 dB with Pb 64%. Postoperative magnetic resonance imaging confirmed complete excision of the tumor. CONCLUSION: An exceptional case of hearing preservation after translabyrinthine excision of a small acoustic tumor illustrates how it may be possible to preserve cochlear hair cells and neurones simultaneously in certain selected cases. A review of the surgical events shows the value of sealing the cochlear duct with bone wax, selectively removing the vestibular nerves with the tumor by sharp dissection, and safeguarding the meatal segment of the anterior inferior cerebellar artery by a limited dural incision.- - - - - - - - - - ranking = 1keywords = canal (Clic here for more details about this article) |
2/178. Persistent bilateral hearing loss after shunt placement for hydrocephalus. Case report.Transient hearing decrease following loss of cerebrospinal fluid (CSF) has been reported in patients undergoing lumbar puncture, spinal anesthesia, myelography, and/or different neurosurgical interventions. The authors present the first well-documented case of a patient with persistent bilateral low-frequency sensorineural hearing loss after shunt placement for hydrocephalus and discuss the possible pathophysiological mechanisms including the role of the cochlear aqueduct. These findings challenge the opinion that hearing decreases after loss of CSF are always transient. The authors provide a suggestion for treatment.- - - - - - - - - - ranking = 0.010115848429625keywords = spinal (Clic here for more details about this article) |
3/178. Bilateral facial nerve schwannomas.facial nerve schwannoma is an uncommon tumor and bilateral facial nerve tumors are extremely rare. A case is presented in which neuromas affecting the intra-canalicular and labyrinthine portions of both facial nerves occurred. Radiologic assessment demonstrated the origin of these tumors. Eventual tumor involvement of the sole functioning cochlea resulted in the development of total hearing loss. Management entailed symptomatic care and surgical resection. Auditory rehabilitation was attempted using cochlear implantation, but results have not been satisfactory. Genetic screening identified a mutation in the NF2 gene. It is proposed that this patient's condition should be considered a variant of neurofibromatosis 2 and that bilateral facial neuromas should be included in the clinical criteria for this condition.- - - - - - - - - - ranking = 0.5keywords = canal (Clic here for more details about this article) |
4/178. cochlear nerve aplasia: its importance in cochlear implantation.OBJECTIVE: The objective of this study was to outline the possible implications and potentially valuable techniques for managing cases in which the neural integrity of the peripheral auditory system is in question. STUDY DESIGN: This study was a retrospective case review. SUBJECT AND METHOD: A 3-year-old child with a profound blilateral sensorineural hearing loss was assessed for suitability of cochlear implantation. Audiologic tests confirmed that the child met the audiologic criteria for cochlear implantation. Computed tomographic scanning and magnetic resonance imaging were undertaken. RESULTS: Computed tomographic scanning showed bilateral narrow internal auditory canals. magnetic resonance imaging showed the absence of the acousticofacial bundle on the left side and possible atrophy of the bundle on the right. After detailed discussion, the parents elected to proceed with implantation on the right ear using the Nucleus mini-22 cochlear implant. Tuning of the device resulted in myogenic facial activity with no electrically stimulated auditory sensation. Postoperative electrophysiologic testing confirmed the presence of a compound muscle action potential only. CONCLUSIONS: Seven months after implantation, the child was explanted uneventfully. The electrical auditory nerve action potential and the electrically evoked auditory brainstem response, using intracochlear stimulation, are potentially valuable measurements to assess neural integrity before the decision to proceed with implantation is made.- - - - - - - - - - ranking = 0.5keywords = canal (Clic here for more details about this article) |
5/178. Neurotological evaluation of vertical semicircular canal function in inner ear malformation. A case report.A 9-year-old boy with inner ear malformation complained of slight deafness and unsteadiness. CT revealed a normal cochlea despite enlargement of the lateral semicircular canals. The vertical semicircular canals developed more or less normally. The caloric test showed complete canal paresis bilaterally; however, a horizontal rotational stimulus elicited a vestibulo-ocular response, which showed only rightward and downward nystagmus, and their maximal slow-phase velocities were low. In addition, the examination of the vertical semicircular canal function using the head-tilted rotation test revealed a more active response, and the maximal slow-phase velocities were higher than those of a standard horizontal rotational test. These results suggest that the function of the vertical semicircular canal was well preserved and that it may have perceived the horizontal acceleration instead of the lateral semicircular canal.- - - - - - - - - - ranking = 5keywords = canal (Clic here for more details about this article) |
6/178. Carabid beetle invasion of the ear in oman.Two cases of human ear invasion by a predaceous beetle, Crasydactylus punctatus Guerin (Coleoptera; Carabidae), are reported from the Sultanate of oman. The first case was that of a 35-year old woman who suffered a severe otologic injury caused by the biting and chewing of the external auditory canal and the tympanic membrane. The beetle then entered the middle ear and caused sensorineural hearing loss. The second case involved a 22-year-old male from whose ear a specimen of the same species was successfully removed after it was immobilized with 10% lidocaine spray. These cases are presented with discussion.- - - - - - - - - - ranking = 0.5keywords = canal (Clic here for more details about this article) |
7/178. Isolated primary unilateral stenosis of the internal auditory canal.Congenital primary stenosis of the internal auditory canal (IAC) may exist in isolation or along with a number of other osseous anomalies of the temporal bone. Most of the literature on IAC stenosis is concerned with its effect on the outcome of cochlear implantation (i.e. patients with profound bilateral hearing loss). In addition, some degree of canal asymmetry has been noted in patients with normal hearing, questioning the causal relationship of this finding to deafness. We describe two children with computed tomography (CT) documented severe primary unilateral narrowing of the IAC and an associated ipsilateral sensorineural hearing loss. Typical radiographic findings are described, and the relevant developmental pathology is discussed. The ipsilateral association of stenosis and hearing loss strengthens the link between narrowing of the IAC and deafness.- - - - - - - - - - ranking = 3keywords = canal (Clic here for more details about this article) |
8/178. Unilateral sensorineural hearing loss and its aetiology in childhood: the contribution of computerised tomography in aetiological diagnosis and management.OBJECTIVES: The objective of this study was to identify factors correlated with the CT outcome and to examine the contribution of the CT scan in the aetiological diagnosis and management of unilateral sensorineural hearing loss in childhood. methods: The records of 35 consecutively investigated patients by the audiology Department of Great Ormond Street Hospital between January 1996 and June 1998 were reviewed. The CT results, population sample characteristics, initiation of further investigations after the CT results and management decisions based on the CT results were tabulated and analysed. RESULTS: In a series of 35 consecutively investigated children with unilateral sensorineural hearing loss, 11 CT scans were identified as abnormal. The CT findings were: labyrinthitis ossificans (3), unilaterally dilated vestibular aqueduct (2), bilaterally dilated vestibular aqueduct (2), unilateral deformity of the cochlea ('Mondini') (1), unilateral severe labyrinthine dysplasia (1), unilateral markedly narrow internal acoustic meatus (1), bilaterally dilated lateral semicircular canals (1). The presence of progressive hearing loss was a significant predictor of abnormal CT outcome, while the severity of hearing loss was not. The CT scans offered valuable information regarding the aetiological diagnosis in all cases and, in addition, prompted the appropriate vestibular rehabilitation in three cases, further investigations in four (with dilated vestibular aqueduct) and hearing preservation counselling in two (bilateral DVA) (seven out of 35 = 20%). CONCLUSION: All children with unilateral sensorineural hearing loss should have a CT scan of the petrous pyramids/IAMs performed at some stage, as not only aetiology but also prognosis and management of these cases may be significantly influenced by the CT outcome.- - - - - - - - - - ranking = 0.5keywords = canal (Clic here for more details about this article) |
9/178. An unusual complication of cochlear implant: benign paroxysmal positional vertigo.Three days after the initial fitting of the cochlear device a 40-year-old woman complained of severe rotational vertigo following head movements associated with neurovegetative symptoms. Otoneurological evaluation revealed a horizontal paroxysmal positional nystagmus beating towards the lowermost ear, induced by rolling the patient's head from supine both to the right or to the left lateral position suggesting the diagnosis of benign paroxysmal positional vertigo of the left horizontal semicircular canal. The nystagmus characteristics were the same whether the cochlear device was switched on or off. The hypothesis of an otolith dislodging due to the electrical stimulation during the initial fitting is discussed.- - - - - - - - - - ranking = 0.5keywords = canal (Clic here for more details about this article) |
10/178. cochlear implantation for auditory rehabilitation in Camurati-Engelmann disease.Camurati-Engelmann disease (progressive hereditary diaphyseal dysplasia) is a rare sclerotic bone disease involving the diaphyses of the long bones, skull base, and clavicles. Progressive sclerosis of cranial nerve foramina has been implicated in cranial nerve deficits. including facial nerve palsy, vestibular disturbances, and hearing loss. Two patients with Camurati-Engelmann disease and concomitant sensorineural hearing loss are presented. Both patients were evaluated for cochlear implantation. One patient was successfully implanted after preoperative imaging revealed no involvement of the internal auditory canals. The porous nature of the affected bone, however. necessitated the inactivation of 1 electrode to prevent facial nerve stimulation. A second patient was rejected as a potential implant recipient due, in part, to narrow internal auditory canals and rapidly progressive disease. The otologic manifestations of Camurati-Engelmann disease are reviewed, and issues related to cochlear implantation in this rare disease are discussed.- - - - - - - - - - ranking = 1keywords = canal (Clic here for more details about this article) |
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