SEARCH · PubMed Health

Results for “Cochlear Nerve”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources

PubMed2004

[Herpes zoster oticus: symptom constellation and serological diagnosis].

BACKGROUND: Herpes zoster oticus is a rare illness with cutaneous symptoms (eruptions) and a colored picture of brain nerve failures. The clinical symptoms, the symptom constellation, diagnostics and therapy, however, have been examined till now only in few studies. PATIENTS AND METHODS: In this study 91 cases of a zoster oticus were looked at in retrospect from the complete archives of the university ENT clinic Jena/Germany in the period from 1932 to 2001. Inclusion criterion was the occurrence eruptions in the ear region. The demographic data, subjective and objective symptoms, the symptom constellations, diagnostic methods and the therapy were arranged. RESULTS: Women (68.1 %) were concerned more frequently than men (31.9 %). The average illness age was 51.2 days. The prodromal stage lasted for 2.2 days in the average. Earache (50.2 %) and headache (11.0 %) were the most frequent first symptoms. No prodroma appeared in 27.5 % of the cases. The facial nerve (86.8 %) was most frequently affected, the vestibular nerve in 76.9 % and the cochlear nerve in 36.3 %. Other brain nerve damages were extremly rare. The therapy success was identical with regard to the brain nerve regeneration at all times. A positive antibody titer for VZV-IgM and/or IgA or an IgG is a sign for an acute infektion. VZV-IgA antibody titers appeared more constantly, frequent and early than an IgM. CONCLUSIONS: Women have a greater risk of falling ill at a zoster oticus than men. Although more than 72 hours is behind the beginning of the symptoms in this study, treatment with virostatic drugs should always be carried out in zoster oticus. Different therapy methods do not have any influence to the success therapy of the therapy. The facial nerve showed the best cure trend. A postzosteric pain develops approximately the half of the cases at the zoster oticus. The serological diagnostic is not necessary in clinically clear cases.

Adolescent↗

PubMed1991

Intracanalicular acoustic neurinomas.

The cases of 16 patients with acoustic neurinomas confined to the intracanalicular area are presented. These represent 2.7% of the 600 patients with acoustic neurinomas consecutively operated upon at the Neurosurgical Clinic at Nordstadt Hospital during the last 8 years. The comparatively earlier onset of vestibular symptoms and signs was characteristic of this group and precipitated diagnosis. The diagnostic reliability of magnetic resonance imaging was at least equivalent to that of air computed tomographic cisternography. Complete tumor removal was accomplished via the suboccipital approach in all patients, with 100% preservation of facial nerve and facial function; the cochlear nerve was preserved anatomically in 100% of the patients and functionally in 57%. No recurrence has occurred during follow-up periods of up to 8 years in all 16 patients. A broad spectrum of the current literature is considered, and purely intracanalicular acoustic neurinomas are discussed with regard to clinical characteristics, diagnostic steps-including neuroradiological and neurophysiological approaches-and surgical treatment and results.

Adult↗

PubMedDate not supplied

Molecular plasticity in the rat auditory brainstem: modulation of expression and distribution of phosphoserine, phospho-CREB and TrkB after noise trauma.

We induced acoustic trauma by applying click stimuli of 130 dB (SPL) for 30 min to one ear of adult rats. This treatment resulted in an instant and permanent threshold shift of 96 dB in the affected ear. A massive reduction of cochlear nerve fibers in the ventral cochlear nucleus (VCN) was demonstrated by tracing them from the cochlea of rats that survived acoustic overstimulation for 1 year or longer. In the auditory brainstem, we observed a deprivation-dependent appearance of fibers positive for tyrosine receptor kinase B in the ipsilateral VCN between day 3 and day 21 after trauma and an increase in phosphoserine immunostaining in the neuropil of the ipsilateral VCN and in neurons of the contralateral lateral superior olive during the first 30 days after trauma. Immunoreactivity for the cAMP response element binding protein in its phosphorylated form was transiently depressed in the ipsilateral inferior colliculus immediately after trauma and was elevated as late as 7 months after trauma in the ipsilateral VCN. Apparently, a unilateral acoustic overstimulation entails specific regulations of the activity of plasticity-associated molecules through phosphorylation and includes changes to neurotrophin signaling between neurons of the auditory brainstem.

Animals↗

PubMed1999

Bacterial meningitis in adults: demonstration of inner ear involvement using high-resolution MRI.

OBJECTIVE: To visualize the sites involved in audiovestibular dysfunction during bacterial meningitis in adults and to relate these findings to the extent of hearing impairment and vestibular dysfunction. BACKGROUND: Hearing impairment is among the most frequent complications of bacterial meningitis. METHODS: High-resolution MRI (HR-MRI) of the inner ear was performed in seven adult patients with hearing loss as a complication of bacterial meningitis. RESULTS: Five patients had unilateral (n = 1) or bilateral (n = 4) contrast enhancement of vestibulocochlear structures. The structures most frequently involved were the cochlear nerve (n = 9), the first cochlear turn (n = 9), the vestibulum (n = 9), and the semicircular canals (n = 7). There was a significant correlation between clinical and MRI findings: all nine ears with cochlear enhancement were deaf (hearing loss >90 dB), whereas none of the five ears with normal MRI findings had hearing losses of more than 90 dB (range, 30 to 70 dB; p = 0.0005). Vestibular dysfunction as revealed clinically and by quantitative vestibular function testing was found in six of seven patients (11 of 14 ears). Five of these patients (nine ears) also demonstrated enhancement of the vestibular organ on high-resolution MRI of the inner ear. CONCLUSIONS: High-resolution MRI can visualize the involvement of vestibulocochlear structures in bacterial meningitis in both cooperative and consciously impaired patients. These findings suggest a correlation between abnormalities on MRI and the extent of cochlear dysfunction.

Adolescent↗

PubMed1998

Acoustic Tumor Surgery and Tinnitus.

A total of 311 patients with a unilateral acoustic neurinoma were operated on via the enlarged middle cranial fossa approach. A total tumor removal was achieved in 98% of cases. The mortality was 0.6%. Overall in acoustic neurinoma surgery, the percentage rates of meningitis (1.6%), cerebrospinal fluid fistula (1.6% requiring surgery), and neurological deficits were fairly low. The facial nerve could be preserved anatomically in 99%. A House I or House II classification was demonstrated in 91% of all tumors and in 98% of small- and medium-sized tumors. Preservation of the hearing function was possible in 49% of all patients (71% in small tumors). A positive effect on tinnitus usually occurred in 45% of cases. The enlarged middle cranial fossa approach allows function-preserving surgery of the cranial nerves (e.g., the facial and cochlear nerves) and cerebral structures, even including total removal of large acoustic neurinomas of up to 3-4 cm.

Journal Article↗

PubMed1998

Advances in monitoring of seventh and eighth cranial nerve function during posterior fossa surgery.

OBJECTIVE: This study aimed to illustrate some recent advances in intraoperative monitoring of the seventh and eighth cranial nerves (i.e., direct recording of cochlear nerve action potentials [CNAPs] and facial nerve action potentials [FNAPs]). STUDY DESIGN: Reports of representative cases and average postoperative results obtained in subjects submitted to cerebellopontine angle surgical procedures are examined. Results obtained in patients with direct recording techniques are compared with those obtained with the classical monitoring techniques (auditory brain stem response [ABR], electrocochleography [ECoG], facial electromyography [EMG]). SETTING: The study was conducted at an Ear Nose and Throat Department, University of Verona, Verona, Italy. INTERVENTION: Intraoperative monitoring during cerebellopontine angle surgery was performed. RESULTS: Patients monitored with direct audiomonitoring techniques presented better postoperative auditory functions compared to patients monitored with ABR. The FNAP and EMG groups showed FN outcome that did not differ significantly. CONCLUSIONS: Intraoperative monitoring of cranial nerves furnishes a valid tool for identification of neural structures, prevention of damage, understanding of the pathophysiology of damage, and prediction of postoperative function. The fundamental prerequisite for obtaining optimal benefits from monitoring is the use of techniques of direct and continuous electrophysiologic recording with instantaneous feedback to the surgeon, such as CNAPs and FNAPs.

Adolescent↗

PubMed1996

[Clinical application of enzyme linked immunosorbent assay in testing antibodies against cochlear tissues and nerve tissues].

Fifty-two patients with idiopathic sensorineural hearing loss and 20 controls were examined by enzyme linked immunosorbent assay (ELISA) with cow cochlear antigen (CCAg) and cow cochlear nerve antigen (CCNAg). The antibody level against CCAg was 0.3811 +/- 0.743 in the control group and 0.9241 +/- 0.2408 in the experimental group (OD, x +/- 2s, P < 0.01). Compared with the x +/- 2s antibody level of the control group, the antibody level of 24 of 52 (46%) patients of the experimental group was positive. The antibody level against CCNAg was 0.2254 +/- 0.382 in the control group and 0.2331 +/- 0.656 in the experimental group (P > 0.05). Compared with the x +/- 2s antibody level of the control group, the antibody level of 6 of 52 patients (11.5%) of the experimental group was elevated. It is suggested that ELISA method can be used as quantitatively in the diagnosis of autoimmune inner ear diseases. Moreover, the serum antibodies against CCNAg detected in this experiment suggest that some of autoimmune inner diseases might be retrocochlear.

Adolescent↗

PubMed1987

Surgical accessibility of the cochlear nuclear complex in man: surgical landmarks.

Patients deafened by bilateral acoustic tumors or by transections of both cochlear nerves are excluded as candidates for cochlear implantation. These patients require more proximal stimulation of the auditory pathway. One potential area for such stimulation is the cochlear nuclear complex (CNC) in the lateral recess of the fourth ventricle. If animal studies establish the safety and efficacy of such stimulation, electrical stimulation of the human cochlear nuclear complex may become an accepted treatment modality for this select group of patients. Such implantation requires that the surgeon accurately locate the cochlear nuclear complex without destruction of vital surrounding neural and vascular structures. With ten fresh human brains, oriented for a translabyrinthine approach, we determined key anatomical landmarks to the exposed surface of the CNC on both sides of each brain. Using a combination of anatomical landmarks--including the flocculus, eighth nerve root, choroid plexus, and taenia--we located the cochlear nuclear complex (without disruption of surrounding neural or vascular structures) and marked it with colloidal carbon. Access to the CNC was obtained in all 20 specimens, and histologic sections confirmed the carbon marker in the CNC in 19 of 20 specimens.

Cochlea↗

PubMedDate not supplied

Cochlear prostheses. A state-of-the-art review.

Work on cochlear prostheses for the auditory rehabilitation of the profoundly deaf represents a challenging problem. Some early, but perhaps premature, surgical attempts have helped to bring the entire issue into focus. Systemic studies are now under way in many different places. Although the purely engineering problems as well as the surgical ones appear solvable at this time, the remaining unsolved problems lie in two areas: 1) the bioengineering interfacing, i.e., the search for methods needed to connect an engineering (electronic) device to the neural auditory system in an efficient manner; and 2) clinical tests for the assessment of the functional state of the cochlear nerve.

Acoustics↗

PubMed1987

Dégénérescence systématisée optico-cochléo-dentelée.

During the first year of life a girl, the first child of non-consanguineous parents, developed a progressive neurological disease characterized by blindness, severe hypotonia, impaired motor development, microcephaly and mental retardation. Later she became unresponsive to auditory stimuli. She died at the age of 13 months. Post-mortem examination revealed atrophy of the optic nerves and chiasm, lateral geniculate nuclei and superior colliculi, degeneration of the cochlear nerve roots, dorsal and ventral cochlear nuclei, superior olives, lateral lemnisci, medial geniculate nuclei and inferior colliculi and atrophy of the dentate nuclei, hilus and superior cerebellar peduncles. These were consistent with dégénérescence systématisée optico-cochleéo-dentelée. Additional abnormalities included degeneration of the posterior columns in the spinal cord, gracilis and cuneate nuclei and medial lemnisci, atrophy of the spinocerebellar tracts and Clarke's columns, cerebral cortex, cerebellum, chiefly involving the rostral vermis, inferior olivary nuclei and demyelination of the sural nerves.

Cerebellar Diseases↗

PubMed1989

Acoustic neuroma: a review of 392 cases.

A retrospective study was made of all operations for acoustic tumour over a 40-year period. A total of 392 cases are reported. Trends over time and with the size of the tumour are reported. In the current decade all but two tumours were completely resected, the mortality rate was 1.4%, 94% of patients had a good or excellent result, the facial nerve was preserved in 64% of cases (90% of these with acceptable function) and the cochlear nerve in 13.5% (some with hearing). There is a striking dependence on the size of the tumour of the likely outcome of operation.

Cochlear Nerve↗

PubMed2005

Microvascular decompression for primary hemifacial spasm. Importance of intraoperative neurophysiological monitoring.

There is considerable evidence that primary Hemi-Facial Spasm (HFS) is in almost all cases related to a vascular compression of the facial nerve at its Root Exit Zone (REZ) from brainstem, and that Micro-Vascular Decompression (MVD) constitutes its curative treatment. Clinical as well as electrophysiological features plead for mechanisms of the disease in structural lesions at the neural fibers (putatively: focal demyelination at origin of ephapses) and functional changes in the nuclear cells (hyperactivity of the facial nucleus). Lateral Spread Responses (LSRs) elicited by stimulation of the facial nerve branches testify of these electrophysiological perturbations. Monitoring LSRs during surgery is feasible; however the practical value of their intraoperative disappearance as control-test of an effective decompression remains controversial.MVD allows cure of the disease in most cases. Because the VIIIth nerve is at risk during surgery, intraoperative monitoring of Brainstem Auditory Evoked Potentials (BEAPs) is of value to reduce occurrence of hearing loss. Increase in latency of Peak V and decrease in amplitude of Peak I are warning-signals of an excessive stretching of the the cochlear nerve and impairment of the cochlear vascular supply, respectively.

Cochlear Nerve↗

PubMed1995

Microsurgical anatomy of arteries related to the internal acoustic meatus.

The distribution and location of the labyrinthine arteries (LA) have been investigated in 6 adults and 15 human fetuses using microdissection. The LA is a single or double artery that penetrates the internal acoustic meatus (IAM) extending to the arachnoidal, dural, temporal and neural branches and ending at the fundus of the IAM in three terminal branches, namely the anterior vestibular artery (AVA), the vestibulocochlear artery (VCA) and the cochlear artery (CA). When the LA is a single artery, it is located on the cochlear nerve, under the facial nerve, and ends in the hiatus between the cochlear and the vestibular nerves. In cases with a biarterial system, the inferior LA passes under the nerves and becomes the VCA at the fundus of the IAM. The location of the superior LA is similar to that of the LA in the monoarterial system and the superior LA terminates at the cochlear artery and the VCA. The nomenclature, distribution and surgical importance of the two arterial patterns are analyzed.

Adult↗

PubMedDate not supplied

[The sub-occipital approach in functional surgery of acoustic neuroma].

In this study the Authors analyze 380 acoustic neuroma removals carried out from 1972 to 1992 focusing their attention on 90 attempts to save hearing by employing a suboccipital approach. In this series the facial nerve was preserved in 99% of the cases with completely normal function in 78%. The cochlear nerve was anatomically preserved in 96% of the subjects. According to the Shelton-Brackmann classification applied to evaluate hearing results, good hearing (Class A = PTA < or = 30 dB; SDS > or = 70%) was obtained in 12% of the cases, serviceable hearing (Class B = PTA < or = 50 dB; SDS > or = 50%) in 13%, measurable hearing (Class C = any measurable hearing) in 19% and anacusis (Class D) in 56% of the patients. CSF leak occurred in 6.6% of the cases, meningitis in 2.2%, paresis or paralysis of the ninth and tenth cranial nerves in 3% and ataxia in 2%. In acoustic neuroma surgery, hearing preservation is a new but complicated topic. In fact, some operative steps--such as the separation of tumor from nerves and arteries, tumor mass reduction, exposure of the end of the IAC--certainly influence surgical results, but are a matter of uncontrollable variance even within series from the same surgeon and render hearing preservation an innovative idea still awaiting, however, a controllable procedure. The ethical feasibility of hearing preservation is confirmed by our results in which hearing preservation attempts using a suboccipital approach have the same morbidity that the translabyrinthine route would have in the same patient.

Adult↗

PubMed1985

Development of oriented dendritic fields in the dorsal cochlear nucleus of the hamster.

The shapes of the apical and basal dendritic fields of the fusiform cells in the dorsal cochlear nucleus of the hamster were analyzed quantitatively. Measurements of the cross-sectional areas of the dendritic fields in planes parallel and perpendicular to planes occupied by the cochlear nerve axons revealed that the apical dendrites have a preferential orientation with respect to the cochlear planes. No consistent orientation of the basal dendrites was apparent. The orientation of the apical dendrites is not present in the neonatal hamster; rather, it develops gradually and is not fully established until after postnatal day 25. Since the cochlear fibers grow into the dorsal cochlear nucleus, establish contacts and become functional before day 25, the presence of the cochlear input might be a prerequisite for the development of oriented dendritic trees. In adult hamsters that have had their cochlear input eliminated during infancy, the apical dendritic trees of the fusiform cells are not oriented normally. The results suggest that the presence of the afferent input is necessary for the differential growth that leads to the development of oriented dendritic trees.

Animals↗

PubMed1984

Single unit responses in the cochlear nucleus of the deaf quivering mouse.

Mice homozygous for the autosomal recessive gene quivering do not have a classical Preyer reflex and appear to be deaf. Round window recordings including both cochlear microphonics and compound action potentials failed to reveal any abnormality. However, auditory-evoked potentials recorded from the inferior colliculus (IC) are small with long latencies, and the thresholds are at least 50 dB higher than those recorded in controls. This suggests that the auditory deficit arises in the auditory pathway between the cochlear nerve and IC and underlines the need for a description of the functioning of the cochlear nucleus (CN). Single units were recorded extracellularly from the CN in 9 mutants (qv/qv) and 11 control animals (+/qv, or +/+) in the age range 60-120 days. The spike response pattern in mutant animals was broadly similar to that in the controls: a sustained response with monotonic rate-intensity functions. In addition the mean Q10dB for units in the mutants was similar to that of the controls. However, in mutants the group mean threshold at the characteristic frequency was higher and the latency to the first evoked spike at 20 dB above threshold was longer than in controls. Some unit responses in the mutants were similar to those of the controls. Nevertheless, in the quivering mouse, evidence now exists of single unit dysfunction in the cochlear nucleus.

Acoustic Stimulation↗

PubMed1982

Organization of ascending auditory pathways in the pigeon (Columba livia) as determined by autoradiographic methods.

A mixture of tritiated proline and fucose was injected into the labyrinthine endolymphatic space of 5 white king pigeons (Columba livia). Using standard autoradiographic techniques, we observed transsynaptic labeling in ascending auditory pathways to the level of the mesencephalon. Auditory system structures, ipsilateral to the injection site, which labeled heavily were the cochlear nerve, the magnocellular and angular nuclei, and the superior olive. Those ipsilateral structures which were slightly labeled were the lateral lemniscus and the dorsal part of the lateral mesencephalic nucleus. Contralateral structures which labeled were the superior olive, lateral lemniscus, and dorsal part of the lateral mesencephalic nucleus. The results of this study suggest that ascending auditory pathways (to the level of the mesencephalon) in the pigeon are more similar to those described for mammals in general than previously thought.

Abducens Nerve↗

PubMed2004

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.

Audiometry, Evoked Response↗