1/10. Progressive auditory neuropathy in patients with Leber's hereditary optic neuropathy.OBJECTIVE: To investigate auditory neural involvement in patients with Leber's hereditary optic neuropathy (LHON). methods: Auditory assessment was undertaken in two patients with LHON. One was a 45 year old woman with Harding disease (multiple-sclerosis-like illness and positive 11778mtDNA mutation) and mild auditory symptoms, whose auditory function was monitored over five years. The other was a 59 year old man with positive 11778mtDNA mutation, who presented with a long standing progressive bilateral hearing loss, moderate on one side and severe to profound on the other. Standard pure tone audiometry, tympanometry, stapedial reflex threshold measurements, stapedial reflex decay, otoacoustic emissions with olivo-cochlear suppression, auditory brain stem responses, and vestibular function tests were undertaken. RESULTS: Both patients had good cochlear function, as judged by otoacoustic emissions (intact outer hair cells) and normal stapedial reflexes (intact inner hair cells). A brain stem lesion was excluded by negative findings on imaging, recordable stapedial reflex thresholds, and, in one of the patients, olivocochlear suppression of otoacoustic emissions. The deterioration of auditory function implied a progressive course in both cases. Vestibular function was unaffected. CONCLUSIONS: The findings are consistent with auditory neuropathy-a lesion of the cochlear nerve presenting with abnormal auditory brain stem responses and with normal inner hair cells and the cochlear nucleus (lower brain stem). The association of auditory neuropathy, or any other auditory dysfunction, with LHON has not been recognised previously. Further studies are necessary to establish whether this is a consistent finding.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
2/10. A case of isolated nodulus infarction presenting as a vestibular neuritis.We reported a patient with cerebellar infarction who presented with purely isolated vertigo, ipsilesional spontaneous nystagmus, and contralesional axial lateropulsion without usual symptoms or signs of cerebellar dysfunction. An MRI of the brain showed a small left cerebellar infarct selectively involving the nodulus. A pure vestibular syndrome in our patient may be explained by ipsilateral involvement of nodulo-vestibular inhibitory projection to vestibular nucleus. Clinicians should be aware of the possibility of a nodulus infarction in patient with acute vestibular syndrome, even if the pattern of nystagmus and lateropulsion is typical of a vestibular neuritis.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
3/10. Optico-cochleo-dentate degeneration associated with severe peripheral neuropathy and caused by peroxisomal D-bifunctional protein deficiency.The clinical, neuroradiological, neuropathological and biochemical findings in a patient with optico-cochleo-dentate degeneration (OCDD; OMIM 258700) are presented in a severe case succumbing at the age of 4 years. The electron microscopic and biochemical data showed for the first time that OCDD may occur as the phenotypic expression of D-bifunctional protein deficiency, i.e., a peroxisomal disorder. The boy was born as the first child of healthy, consanguineous parents of Turkish origin. No other family members were affected. The main clinical symptoms consisted of muscle hypotonia ("floppy infant"), generalized epileptic fits, hypacusis, rotatory nystagmus, insufficient pupillary reactions, and mental retardation. Fibroblast cultures revealed D-bifunctional protein deficiency. Neuropathological examination displayed moderate frontoparietal and insular microgyria, and atrophy of the cerebellum. Loss of neurons was severe in the granular layer, the Purkinje cell band of the cerebellum, and rather complete in the dentate nucleus. A corresponding loss of myelinated fibers associated with characteristic periodic acid-Schiff-positive macrophages was most prominent in the white matter of the cerebellum. There was additional severe loss of myelinated fibers in the central portions of the optic nerve, reduction of the nerve fiber density in the cochlear nerve, and reduction of myelinated nerve fibers by about 80-90% in the sural nerve, which has not been studied in previous cases. At the electron microscopic level, characteristic inclusions mainly in perivascular macrophages and astrocytes were the most prominent finding. The inclusions usually showed a bilaminar structure, whereas trilaminar structures, typically seen in adrenoleukodystrophy, and multilaminar structures were less frequently seen.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
4/10. Vascular malformation (so-called hemangioma) of Scarpa's ganglion.vascular malformations of the cerebello-pontine angle (CPA) arising from the capillary plexus surrounding Scarpa's ganglion are rare tumors. We report a case of so-called "hemangioma" of the CPA which was operated on via a trans-labyrinthine approach based on a preoperative diagnosis of vestibular schwannoma. Although there are some differences between these tumors in terms of the clinical, biological and especially MRI findings, surgery is usually performed based on an assumption of vestibular schwannoma. Surgery is the treatment of choice for these lesions as early intervention ensures better postoperative facial function. It is important to make the differential diagnosis if conservative management of vestibular schwannoma is adopted.- - - - - - - - - - ranking = 87.492575574021keywords = ganglion (Clic here for more details about this article) |
5/10. Promontory electrical stimulation in postoperative acoustic tumor patients.Complete deafness can follow acoustic tumor surgery and results from labyrinthine injury, auditory nerve trauma, and/or vascular compromise. A central auditory prosthesis is one potential rehabilitative strategy in such patients. Anatomical studies suggest that some spiral ganglion cells may survive after vascular occlusion, and we have demonstrated responses to electrical stimulation in patients after labyrinthectomy. It was thus hypothesized that patients deafened after a hearing conservation attempt, but maintaining an intact auditory nerve, could utilize an intracochlear implant. To investigate this possibility, promontory electrical stimulation was performed on three patients who had tumors less than 2 cm and who had serviceable preoperative hearing, but no responses postoperatively. Behavioral responses and electrically evoked auditory brainstem and middle latency responses were obtained from two patients, one of whom was 6 years postsurgery. These data indicate that a cochlear implant may be possible after acoustic tumor surgery.- - - - - - - - - - ranking = 17.498515114804keywords = ganglion (Clic here for more details about this article) |
6/10. Are vestibular sensory cells preserved after destruction of Scarpa's ganglion? A study based on metastatic tumors of temporal bone.OBJECTIVE: The contribution of nerve fibers to the maintenance of vestibular sensory cells is a controversial issue in previous studies using animals and has not yet been studied in humans. The authors investigated this issue by observing vestibular end organs in the temporal bone of three patients in whom the internal auditory canal was infiltrated with tumor cells, and Scarpa's ganglion cells showed complete degeneration. STUDY DESIGN: Retrospective case review. SETTING: University Hospital, Department of otolaryngology. patients: Three patients with malignant metastatic temporal bone tumors. INTERVENTION: We investigated the preservative state of vestibular sensory hair cells with the Scalpa's ganglion was destructed. MAIN OUTCOME MEASURES: Maintenances of vestibular sensory hair cells. RESULTS: We found that sensory cells were intact despite the severe destruction of Scarpa's ganglion cells in two of the patients. CONCLUSION: The findings suggest that human vestibular sensory cells can be maintained for an indefinite period after denervation.- - - - - - - - - - ranking = 122.48960580363keywords = ganglion (Clic here for more details about this article) |
7/10. Electrical stimulation of cochlear nucleus in man.Auditory percepts can be produced by electrical stimulation of the cochlear nucleus in man. The ability to locate accurately and stimulate selectively the cochlear nucleus after removal of an acoustic schwannoma was confirmed in this patient. The surgical approach, electrode design, and a discussion of the results and concerns of electrical stimulation are reviewed.- - - - - - - - - - ranking = 6keywords = nucleus (Clic here for more details about this article) |
8/10. vestibular neuronitis. Electron microscopy of Scarpa's ganglion.Scarpa's ganglion and the superior vestibular nerve of a patient with vestibular neuronitis examined under the electron microscope displayed degenerative neuronal changes and axonal lesions considered to be the cause of the clinical features of vestibular neuronitis.- - - - - - - - - - ranking = 87.492575574021keywords = ganglion (Clic here for more details about this article) |
9/10. Ectomesenchymal hamartoma (benign "ectomesenchymoma") of the VIIIth nerve: case report.We report a previously undescribed hamartoma of the VIIIth nerve, consisting of adipose tissue, schwann cells associated with myelinated nerve fibers, well-differentiated smooth and striated muscle fibers, and rare ganglion cells. The tumor was found in a 35-year-old Caucasian female who presented with right-sided hearing loss. The mass, which we designate an "ectomesenchymal" hamartoma, most likely developed from pluripotent neural crest cells ("ectomesenchyme"), which are capable of differentiating into a variety of neuroectodermal and mesenchymal cell types. The development of the neural crest, the concept of "ectomesenchyme," and the histogenesis of this tumor are reviewed.- - - - - - - - - - ranking = 17.498515114804keywords = ganglion (Clic here for more details about this article) |
10/10. Ganglionic hamartoma of the intracanalicular acoustic nerve causing sensorineural hearing loss.OBJECTIVE: This article highlights the clinical presentation and treatment issues of ganglionic hamartoma of the internal auditory canal and emphasizes the similarity of this lesion to acoustic neuroma regarding its audiologic and radiographic characteristics. STUDY DESIGN: This article is composed of case reports and a literature review. SETTING: The study was performed at a university hospital/tertiary referral center. PATIENT: A patient with biopsy-proven ganglionic hamartoma of the acoustic nerve was studied. INTERVENTION: Intervention consisted of surgical therapy. MAIN OUTCOME MEASURE: The main outcome measure was clinical evaluation. RESULTS: The result was successful removal of lesions with facial nerve preservation. CONCLUSIONS: An intracanalicular ganglionic hamartoma resulted in progressive sensorineural hearing loss and magnetic resonance imaging findings suggestive of small acoustic neuroma. This lesion, composed of an admixture of ganglion cells, fibroadipose-tissue, and normal myelinated axons, although rare, should be added to the differential diagnosis of internal auditory canal lesions.- - - - - - - - - - ranking = 69.994060459217keywords = ganglion (Clic here for more details about this article) |
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