Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Vestibular Neuronitis”

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 811 records · Page 45Linked to original sources
PubMed1988

Why do vestibular destructive procedures sometimes fail?

Vestibular nerve specimens and one temporal bone, from patients with vestibular symptoms after destructive surgery on the vestibular system, were studied by light microscopy. Surviving nerve axons in three specimens that followed retrolabyrinthine vestibular nerve section (RLVNS) were counted and compared to normative data. Results are consistent with persistence of the central processes of primary vestibular neurons in three specimens from patients who had persistent symptoms and ice-water caloric responses after RLVNS. Incomplete neurectomy probably results from anatomic variations in the plane of separation of the vestibular and cochlear portions of the eighth nerve in the posterior fossa. Regeneration neuromas were found in the vestibule after a complete transmastoid labyrinthectomy and a Fick sacculotomy; this indicates that wide degrees of injury to the labyrinth may provoke this response. Disabling unsteadiness after labyrinthectomy may or may not respond to revision surgery (translabyrinthine vestibular nerve section). The indications for revision surgery are discussed. The excision of Scarpa's ganglion by the translabyrinthine route offers the best chance to ensure complete removal of peripheral vestibular tissue, minimize postoperative unsteadiness, and prevent neuroma formation.

Adult↗
PubMed2003

An in situ hybridization and immunofluorescence study of glycinergic receptors and gephyrin in the vestibular nuclei of the intact and unilaterally labyrinthectomized rat.

We investigated whether the expression of glycinergic receptor (GLYR) subunits of gephyrin and of their mRNAs in the medial vestibular nuclei are affected following unilateral labyrinthectomy. Specific radioactive oligonucleotide probes recognizing the sequences encoding alpha1-3 and ss subunits of GLYR and the anchoring protein gephyrin were used to probe sections of vestibular nuclei. Signals in these in situ hybridization experiments were detected with film or by emulsion photography. Animals were killed at various times following the lesion: 5 h, 1, 3, 8, 30 and 60 days. Specific monoclonal GLYR and gephyrin antibodies were also used to determine GLYR and gephyrin immunoreactivity in control and operated rats (5 h, 1, 3 and 8 days post-lesion). In normal animals, several brainstem regions including the lateral, medial, superior and inferior vestibular nuclei contained mRNAs for gephyrin and the alpha1 and beta subunits of GLYR, and expressed the GLYR and gephyrin polypeptides. In unilaterally labyrinthectomized rats, no asymmetry was detected on autoradiographs between the two medial vestibular nuclei with any of the oligonucleotide probes used, or at any time following the lesion. No difference in the immunofluorescence staining was observed between the intact and deafferented medial vestibular nuclei of lesioned animals or between the vestibular nuclei of lesioned and controls rats. Thus, deafferentation of the vestibular nuclei did not affect the expression of gephyrin, of the various GLYR subunits, or of their mRNAs in the deafferented and intact medial vestibular nuclei. It is therefore unlikely that GLYR and gephyrin modulation contribute significantly to the recovery of the resting discharge of the deafferented medial vestibular neurons and consequently to the restoration of a normal posture and eye position.

Action Potentials↗
PubMed1976

[Experimental vestibulopathy produced as a result of formation of a generator of pathologically enhanced excitation in the vestibular nuclei (phenomenon of a determinative dispatch station)].

A possibility of formation of a generator of pathologically enhanced excitation in the system of the vestibular nuclei of the medulla oblongata by disturbance of their inhibitory processes (resulting in development of contralateral rotatory motions in animals) was shown. Experiments with electrical stimulation of the lateral vestibular nucleus and its coagulation showed the system of the vestibular neurons organizing the synchronous message by the vestibulo-spinal pathways to underlie the generator of the pathologically enhanced excitation. It was concluded that the generator of the pathologically enhanced excitation formed in the lateral vestibular nucleus as a result of disturbed inhibition underlied the hyperactive determinative dispatch station causing the syndrome of vestibulopathy

Animals↗
PubMed1983

Axon collaterals to the extraocular motoneuron pools of inhibitory vestibuloocular neurons activated from the anterior, posterior and horizontal semicircular canals in the cat.

The branching pattern of inhibitory vestibuloocular neurons and their synaptic contacts with extraocular motoneurons were studied by means of spike-triggered averaging and local stimulation techniques. Individual vestibuloocular neurons activated by stimulation of the ampullary nerve of the anterior semicircular canal (ACN) inhibited motoneurons in both the ipsilateral (i-) trochlear nucleus and i-inferior rectus motoneuron pools. Individual vestibuloocular neurons receiving input from the ampullary nerve of the posterior semicircular canal (PCN) inhibited motoneurons in both the i-inferior oblique and i-superior rectus motoneuron pools. Probably, these axonal trajectories underlie conjugate eye movement during vertical head rotation. No conclusive evidence was found to indicate that single inhibitory vestibular neurons receiving input from the horizontal semicircular canal (HCN) give off axon collaterals to the i-abducens and the contralateral medial rectus motoneurons. A separate projection of HCN-related neurons to motoneurons supplying the lateral and medial rectus muscles might be useful for convergence during horizontal head movement.

Abducens Nerve↗
PubMed1982

Synapse formation is related to the onset of neuron-specific enolase immunoreactivity in the avian auditory and vestibular systems.

Neuron-specific enolase (NSE) is a unique form of the glycolytic enzyme, enolase, which, in the brain, is strictly localized in differentiated neurons and neuroendocrine cells. In this report evidence is presented that NSE is first seen in the cell bodies of developing chick auditory and vestibular neurons shortly after the time when they first form immature synapses. Subsequently, immunoreactive NSE increases and spreads into transiently appearing structures which participate in the morphogenesis of mature synaptic arrangements. These data correlate synaptogenesis with the differentiation of a specific neuronal enzyme.

Animals↗
PubMed1979

[Function returning without and with recovery nystagmus after sudden unilateral isolated vestibular loss (author's transl)].

The restoration of peripher labyrinthine excitability after sudden unilateral isolated vestibular loss shows a different behaviour: It can happen with or without recovery nystagmus with a numerical nearly equal frequency. In a follow-up of 44 patients with unilateral vestibular loss of vascular genetics the objective and subjective characteristics of both states are described. In explanation of it a lesion of variable etiology in the region of the vestibular artery and a supposition of a not yet or already occured compensation of the disturbed tonus balance in the nuclear area are not sufficient. Rather the origin of the different clinical states of recovery phenomenon must be presumed in all probability as the result of a primary and secondary retrograde degeneration of the vestibular neurons. Thereby the distance of the lesion from the Scarpa ganglion is presumably of decisive importance.

Electronystagmography↗
PubMed1983

Vestibular afferent inputs to lobules I and II of the cerebellar anterior lobe vermis in the cat.

Vestibular nerve stimulation evoked mossy fiber responses in lobule I and a part of lobule II of the cerebellar cortex in the anesthetized cat. The latencies of the N2 and N3 potentials were in the range of 1.7-2.0 and 3.2-5.0 ms, respectively. The contribution of both primary and secondary vestibular neurons in producing these responses were indicated by electrophysiological methods.

Afferent Pathways↗
PubMed1998

The combined effects of trkB and trkC mutations on the innervation of the inner ear.

Previous research has demonstrated that only the two neurotrophins and their cognate receptors are necessary for the support of the inner ear innervation. However, detailed analyses of patterns of innervation in various combinations of neurotrophin receptor mutants are lacking. We provide here such an analysis of the distribution of afferent and efferent fibers to the ear in various combinations of neurotrophin receptor mutants using the lipophilic tracer Dil. In the vestibular system, trkC+/- heterozygosity aggravates the trkB-/- mutation effect and causes almost complete loss of vestibular neurons. In the cochlea innervation, various mutations are each characterized by specific topological absence of spiral neurons in Rosenthal's canal of the cochlea. trkC-/- mutation alone or in combination with trkB+/- heterozygosity causes absence of all basal turn spiral neurons and afferent fibers extend from the middle turn to the basal turn along inner hair cells with little or no contribution to outer hair cells. Both types of basal turn spiral neurons appear to develop and project via radial fibers to inner and, more sparingly, outer hair cells. Simple trkB-/- mutations show a reduction of fibers to outer hair cells in the apex and, less obvious, in the basal turn. Basal turn spiral neurons may be the only neurons present at birth in the cochlea of a trkB-/- mutant mouse combined with trkC+/- heterozygosity. In addition, the trkB-/- mutation combined with trkC+/- heterozygosity has a patchy and variable loss of middle turn spiral neurons in mice of different litters. Comparisons of patterns of innervation of afferent and efferent fibers show a striking similarity of absence of fibers to topologically corresponding areas. For example, in trkC-/- mutants afferents reach the basal turn, spiraling along the cochlea, rather than through radial fibers and efferent fibers follow the same pathway rather than emanating from intraganglionic spiral fibers. The data presented suggest that there are regional specific effects with some bias towards a specific spiral ganglion type: trkC is essential for support of basal turn spiral neurons whereas trkB appears to be more important for middle and apical turn spiral neurons.

Animals↗
PubMed1986

New clinical finding in vestibular neuritis: high-frequency audiometry hearing loss in the affected ear.

Twenty-one patients with established vestibular neuronitis were examined otoneurologically and audiologically. High-frequency audiometry up to 20,000 Hz was performed on all the patients. In 17 cases a high-frequency hearing loss was greater in the ear with vestibular neuritis. The mean hearing loss difference varied from 14 dB to 24 depending on the frequency. Our results reveal that in most cases of vestibular neuritis there are no isolated vestibular lesions, but most cases also involve an auditory end-organ lesion. This finding is in unison with the anatomic conditions of the cochlea and the vestibular end-organ.

Adult↗
PubMed1989

Horizontal vestibulo-ocular reflex after acute peripheral lesions.

We studied the dynamics of the horizontal vestibulo-ocular reflex using a broad range of sinusoidal rotational stimuli in 14 patients with acute unilateral peripheral vestibular lesions. From plots of slow phase velocity (SPV) versus stimulus velocity (phase shifts removed) we calculated the DC offset and gain to ampullopetal (AP) and ampullofugal (AF) stimulation of the remaining intact labyrinth. DC offset values were highly correlated with spontaneous nystagmus SPV values for all frequencies (0.0125-0.8 Hz) and amplitudes (30-120-deg/sec) of stimulation. Mean AP gain values were consistently higher than mean AF values with the greatest difference occurring at low frequencies of stimulation. Saturation nonlinearities were present with AF stimulation at high amplitudes. These findings can be explained by dynamic asymmetries at the level of the primary and secondary vestibular neurons.

Acute Disease↗
PubMed1993

Experimental reactivation of HSV-I in rat vestibular ganglia.

Rats with no clinical symptoms after inoculation were administered with cyclophosphamide in order to reactivate HSV-I in the vestibular ganglia. After this immunosuppression, the vestibular ganglia, trigeminal ganglia, cerebrum, cerebellum and brainstem were examined immunohistologically in order to detect HSV-I. HSV-I antigen could not be detected by using indirect immunofluorescence or the ABC method, however, it could be detected by using the PCR method. In this study, latent infection of HSV-I was shown but reactivation could not be established. We need further investigations to determine the reactivation of HSV-I in the vestibular ganglia, to obtain an animal model of vestibular neuronitis.

Animals↗
PubMed1992

Spatial disorientation and dysfunction of orientation/equilibrium reflexes: aeromedical evaluation and considerations.

Loss of spatial awareness has been implicated as a direct causal factor in 4-10% of serious aircraft mishaps and 10-20% of fatal aircraft mishaps (7). Spatial disorientation in flight usually results from misperception of visual, vestibular, or proprioceptive cues. Pathologic causes have rarely been implicated. A student naval aviator with recurrent loss of spatial awareness due to a defective vestibulo-ocular reflex (VOR), presumably from vestibular neuronitis in adolescence, is reported. His chief complaint, an inability to focus on the instrument panel during turbulent instrument meteorological conditions (IMC), resulted in spatial disorientation and adverse flight attitude. A simple test of visual-vestibular interaction, the dynamic visual acuity test, could identify a defective vestibulo-ocular reflex in aviation personnel. An absent or defective vestibulo-ocular reflex has potential for disorientation in instrument flight. A comprehensive vestibular function test battery is indicated in individuals with recurrent or overwhelming spatial disorientation who fail a screening dynamic visual acuity test. The aeromedical disposition of vertigo and dysequilibrium is discussed.

Adult↗
PubMed1980

[Vestibular reactions of neurons of the cerebellar nucleus dentatus and nucleus interpositus in cats].

The response of interpositus and dentate neurons to the sinusoidal tilts in the frontal plane were studied in thalamic cats. In interpositus nucleus 65% neurons responded to the tilts. Their responses were not uniform: some neurons showed an increased activity during the contralateral tilt, others--during ipsilateral tilt, and some neurons--during tilts in both directions. Dentate neurons did not respond to tilts. The peculiarities of vestibular responses of neurons in different cerebellar nuclei are discussed.

Animals↗
PubMed1991

A note on the development of the vestibulo-ocular pathway in the chicken.

The vestibulo-ocular pathways have been examined in embryonic chicks using horseradish peroxidase or diI as retrograde and anterograde tracers. The vestibular neurons project to the rostral, external eye motor nuclei over one or the other of three separate pathways; the ipsilateral and contralateral medial longitudinal fascicle and the contralateral brachium conjunctivum. The brachium conjunctivum component originates dorsally in the superior vestibular region and projects to the contralateral inferior oblique and superior rectus motor nuclei. An ipsilateral component of the medial longitudinal fascicle is labeled from more ventral sites in the vestibulo-cerebellar process and terminates in the ipsilateral superior oblique and inferior rectus nuclei. The contralateral medial longitudinal fascicle component originates still more ventrally and terminates in the contralateral superior oblique and inferior rectus motor nuclei. Accordingly, the vestibulo-ocular pathways in chickens operate predominantly on synergistic pairs of external eye muscles. These selective terminal fields are established within a day or two after the first terminals invade the eye motor nuclei during embryogenesis.

Affinity Labels↗
PubMed2004

An in situ hybridization and immunofluorescence study of GABA(A) and GABA(B) receptors in the vestibular nuclei of the intact and unilaterally labyrinthectomized rat.

We investigated whether the production of the sixteen subunits of the GABA(A) receptors and of the different variants of GABA Breceptors are modulated in rat medial vestibular nuclei (MVN) following unilateral labyrinthectomy. Specific alpha1-6, beta1-3, gamma1-3 and delta GABA(A) and GABA(B) B1 and B2receptor radioactive oligonucleotides were used for in situ hybridization to probe sections of rat vestibular nuclei. Specific antibodies against alpha1, beta2, beta3 and gamma2 subunits of GABA(A) receptors and against GABA( B)receptors were also used to detect a potential protein expression modulation. No asymmetry was observed by autoradiography in the intact and deafferented MVN at any time (5 h to 8 days) following the lesion and for any of the oligonucleotide probes used. Also, no difference in the alpha1, beta2, beta3 and gamma2 of the GABA(A) and in the GABA(B) receptor immunohistochemical signal could be detected between the intact and deafferented vestibular nuclei at any time following the lesion. Our data suggest that GABA(A) and GABA Breceptor density changes most probably were not involved in the early stage of the vestibular compensation process, i.e., in the restoration of a normal resting discharge of the deafferented vestibular neurons and consequently in the recovery of a normal posture and eye position.

Adaptation, Physiological↗
PubMed1999

Differential subcellular immunolocalization of voltage-gated calcium channel alpha1 subunits in the chinchilla cristae ampullaris.

The immunohistochemical localization of alpha1A, alpha1B, alpha1C, alpha1D and alpha1E voltage-gated calcium channel subunits was investigated in the chinchilla cristae ampullaris and Scarpa's ganglia at the light and electron microscopy level with the use of specific antipeptide antibodies directed against these subunits. The stereocilia membrane of type I and type II hair cells was immunoreactive for alpha1B along its entire length. The basolateral membrane of both types of hair cells was alpha1B, alpha1C and alpha1D immunoreactive. Neurons in the Scarpa's ganglia and afferent nerve terminals in the cristae were immunoreactive for alpha1C and alpha1B. No specific immunoreactivity to alpha1A or alpha1E was seen in the sensory epithelia or ganglia. These findings are consistent with the presence of alpha1B (N-type channel), alpha1C and alpha1D (L-type channels) in the vestibular hair cells, and alpha1B (N-type channel) and alpha1C (L-type channel) in primary vestibular neurons.

Animals↗
PubMed1988

Retrograde transport of [3H]-GABA by lateral olivocochlear neurons in the rat.

Injection of [3H]-gamma aminobutyric acid (GABA) into the perilymphatic space of the rat's inner ear resulted in retrograde labeling of a portion of the small efferent olivocochlear neurons within the lateral superior olivary nucleus (LSO). These cells were of similar size as LSO neurons stained immunohistochemically with antibodies to the GABA synthesizing enzyme glutamic acid decarboxylase (GAD). They were of fusiform shape, but smaller than principal LSO cells, which did not stain for GAD and did not accumulate [3H]-GABA. Other efferent cochlear and vestibular neurons were not labeled.

Animals↗
PubMed2006

Lateralised vestibular hypofunction: canal paresis and handedness.

In this retrospective study it was found that 549 out of 1175 patients seen for vestibular assessment within an 8-year period within a district hospital service showed lateralised canal paresis as determined by caloric testing. It was found that there was a tendency for canal paresis, indicative of vestibular hypofunction, to be on the side of handedness. This bias showed statistical significance, (chi-squared, p < .005), for the patients overall, as well as for the 65 left-handers considered separately, (p < .05). Surprisingly, this form of bias does not appear to have been reported previously. The bias was shown most clearly in the largest of the groups defined by sex and handedness, namely that of female right-handers. In this group the prevalence of associated hearing loss was similar for canal paresis on either side. This allowed speculation as to the particular type of disorder to which those cases of canal paresis that were associated with the bias might be due, from which it seemed that migraine, rather than Menière's disease or vestibular neuronitis, was likely.

Aged↗