Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LABYRINTH DISEASES”

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.

At least 1,603 records · Page 89Linked to original sources
PubMed1982

Optokinetic after-nystagmus in man after loss or reduction of labyrinthine function - a preliminary report.

Horizontal optokinetic after-nystagmus (OKAN) was studied in normal volunteers and in patients with either unilateral or bilateral loss of labyrinthine function. Optokinetic stimulation in normal volunteers produced OKAN in the same direction as preceding optokinetic nystagmus (OKN) with a duration of 45-90 seconds and a slowly decreasing slow phase eye velocity. Similar stimulation in the bilateral labyrinthine loss group produced markedly diminished or no OKAN. In the unilateral group when the optokinetic stimulus produced OKN with fast phase to the affected ear, OKAN was markedly diminished or absent and replaced by a nystagmus which was reversed in direction to the preceding OKN. The opposite stimulus produced OKAN similar to the volunteer group. The above results support the observation that in human beings, the production of normal OKAN depends on an intact bilateral peripheral vestibular input and further demonstrates that the technique has lateralizing value in unilateral vestibular disease. These results also suggest that separate storage mechanisms are responsible for producing OKAN in the two directions, and that these storage mechanisms are decoupled from each other.

Dark Adaptation↗
PubMed1991

Clip electrode method for recording eye movements in experimental animals.

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.

Animals↗
PubMed1976

On the mechanism of the Menière attack.

Three theories are discussed dealing with the origin of the Menière attack: 1) The hypothesis of pressure induced changes is disproved. 2. The stimulation of the crista epithelium by a mechanical cupula deviation has been investigated. The results showed that the changes in action potential frequency of the ampullary nerve induced by maintained bending of the cupula, always declined and returned to resting potential frequency within a very short period of time usually within 1 min. Preventing the "elastic return" of the cupula did not change the time constant of this response decline. This proves that a Menière nystagmus lasting for hours, can not be elicited by a mechanical deformation of the cupula. 3) The paralyzing influence on vestibular nerve fibres by K+ ions in endolymph, leaking into perilymph spaces has earlier been demonstrated by the author. When the distended membranous labyrinth ruptures at predestined weak spots, leaking endolymph may reach and paralyze different nerve branches. This can explain all the main symptoms of a Menière attack.

Action Potentials↗
PubMed1994

Cavernous angiomas of the internal auditory canal. A case report and review of literature.

Cavernous angiomas of the internal auditory canal (IAC) are rare. They are angiographically occult; and because the clinical symptoms are similar both in intracanalicular cavernous angiomas and acoustic tumors it had been difficult to differentiate pre-operatively both of these pathologies until the advent of magnetic resonance imaging (MRI). Even nowadays the correct diagnosis may be missed if the patient is imaged only with gadolinium enhanced MRI without prior obtaining a non-contrast MRI. These diagnostic difficulties are illustrated by the report of a related case. The importance of thorough neuroradiological investigations stressed and MRI features, surgical management and relevant literature concerning the cavernous angiomas of the internal auditory canal are discussed.

Adult↗
PubMed2005

VEMP recording by binaural simultaneous stimulation in subjects with vestibulo-cochlear disorders.

To reduce the testing time of vestibular evoked myogenic potentials (VEMP) and the physical efforts of subjects, we studied if VEMP recording by binaural simultaneous stimulation in patients with vestibulo-cochlear disorders can be applicable as a screening test. Twenty-eight patients with vestibulo-cochlear disorders (12 men and 16 women, 22 to 77 years of age) were enrolled in this study. Patients were presented with binaural or monaural click (95 dBnHL) stimulation to record VEMPs. Their VEMP responses to binaural simultaneous stimulation were compared with those of monaural individual stimulation. Twenty-six of the 28 patients (93%) showed the same results in binaural simultaneous stimulation as in monaural individual stimulation. Amplitudes of p13-n23 to binaural simultaneous stimulation showed significant correlation to those of monaural individual stimulation ( r =0.774, P <0.0001 t -test). Peak latencies of p13 and n23 of binaural simultaneous stimulation also showed significant correlation to those of monaural individual stimulation (p13: r =0.684, P <0.0001 t -test, n23: r =0.657, P <0.0001 t -test). The binaural simultaneous stimulation method for VEMP recording is applicable for patients with vestibulo-cochlear disorders as a screening test in the clinic.

Adult↗
PubMed1986

Regional differences of brain glucose metabolic compensation after unilateral labyrinthectomy in rats: a [14C]2-deoxyglucose study.

A unilateral labyrinthectomy was performed on anesthetized adult albino rats. Brain [14C]2-deoxyglucose (2DG) uptake was measured autoradiographically 3.5 h to 20 days later and compared to sham-operated controls. In the vestibular nuclei (nn.) of labyrinthectomized subjects, large left-right differences of 2DG uptake occurred, which decreased over time. The equalization of vestibular nuclear 2DG uptake paralleled behavioral compensation of body, neck and head postural abnormalities, and known equalization of vestibular nuclear cell firing rates during compensation. There was a small difference of 2DG uptake in medial and lateral vestibular nn. 20 days after lesions when animals had a residual head tilt and tonic eye deviation. In the oculomotor nn., trochlear nn. and interstitial n. of Cajal, large left-right differences of 2DG uptake occurred, which did not change over time. The higher 2DG uptake in these nn. occurred ipsilateral to the labyrinthine lesion and did not correlate with the onset and cessation of nystagmus. The persistent asymmetry did appear to correlate with ipsilateral downward and contralateral upward eye deviation which continued for long periods after the lesion. We hypothesize that the non-compensating metabolic asymmetry in the oculomotor and trochlear nn. could be due to lesioned otolithic input to the vestibular nn. which relays to trochlear and oculomotor nn.

Animals↗
PubMed1987

Microsurgical treatment of patients with vestibular and cochlear symptoms.

Eighteen patients with vertigo, tinnitus, and various hearing disturbances were treated by posterior fossa exploration and microvascular decompression of the eighth cranial nerve; they were followed for more than 3 years. After successful decompression of the eighth nerve from offending vessels, the attacks of vertigo disappeared in 11 patients, improved markedly in 3 patients, and improved mildly in 4 patients. The tinnitus vanished in three patients and decreased in nine. The hearing disturbance improved in only five patients and worsened in three. Because of the satisfactory improvement of the attacks of vertigo, which are the most distressing symptoms for patients, we recommend surgical exploration for patients with severe symptoms of vestibular disturbances.

Aged↗
PubMed1988

Atrophy of middle and short stereocilia on outer hair cells of guinea pig cochleas with experimentally induced hydrops.

Scanning electron microscopy was employed to investigate hair cell morphology at different stages in the development of experimentally induced hydrops in the guinea pig. A particular form of morpho-pathology, never before described, was identified as characteristic of hydropic cochleas. The pathology was characteristically identified as atrophy of the short and middle stereocilia on the outer hair cells while the inner hair cell stereocilia did not have such a pathology. The atrophy was restricted to the upper cochlear turns in remarkable correspondence with the low/middle frequency sensitivity loss and was detected only at the end of the period of fluctuating thresholds. These stereocilia perturbations appear therefore to be linked with the threshold fluctuations and represent the first evidence for a clear correlation between hair cell morphology and physiology in the experimental model of endolymphatic hydrops. Such a morphopathology might also be expected to occur in cochleas of Menière's patients but may have been overlooked in the past because of the discrete nature of the pathology.

Animals↗
PubMedDate not supplied

Immunobiology of the inner ear.

Immunologic mechanisms may play an etiologic role in ear disease, and many disorders long considered idiopathic are now being examined for such an immunologic basis. While it is possible that many of these idiopathic diseases will ultimately prove not to be immunologically mediated, the outcome of these research endeavors will certainly clarify some of the basic mechanisms of host immunity involved in ear disease. The immunobiology of diseases that affect the inner ear is discussed from both experimental and clinical viewpoints.

Animals↗
PubMedDate not supplied

Intralabyrinthine osteogenesis in Cogan's syndrome.

Temporal bones from a 64-year-old man who had Cogan's syndrome were examined by light microscopy. Although tissues of the middle ear appeared unremarkable, extensive ectopic bone formation was observed bilaterally in the inner ear membranous labyrinth. Such osteogenesis completely obliterated the cochlear compartments apically. Only the scala tympani compartment of the basal cochlear turn remained patent. Ectopic bone tissue was observed also in the vestibular semicircular canals. Marked degeneration of eighth nerve fibers and associated ganglion cells also was observed. To our knowledge, this report represents only the fourth temporal bone findings of Cogan's syndrome and demonstrates a more advanced pathologic state of inner ear pathology than those reported previously.

Adult↗
PubMed1999

Meningioma of the internal auditory canal with extension into the vestibule.

Meningiomas account for approximately 18 to 19 per cent of all brain tumours. Although they can arise in numerous locations, meningiomas of the internal auditory canal (IAC) are rare. Most tumours that originate in the IAC are schwannomas of the VIIIth cranial nerve (acoustic neuromas). We report a case of a meningioma which appears to originate from the IAC and extends into the vestibule. The clinical findings and the radiographical features of meningiomas of the IAC are similar to those of acoustic neuromas. Pre-operative differentiation between acoustic neuromas and meningiomas of the IAC may be difficult.

Diagnosis, Differential↗
PubMed1970

Medicine 1969.

Explore the source record for details and available documents.

Biomedical Engineering↗