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At least 19 recordsLinked to original sources

PubMed2004

[An anatomic study on the relationship of the recurrent perforating artery and the facial nerve and the vestibulocochlear nerve].

OBJECTIVE: To privde useful anatomic data for the microvascular decompression surgery of the vestibulocochlear nerve in the cerebellopontine angle. METHOD: The recurrent perforating artery related with VN in the cerebellopontine angle were examined with operating microscope in 20 adult head cadavers fixed with formalin. RESULT: The recurrent perforating artery was identified in 40 specimens with cerebellopontine angles. There was one recurrent perforating artery in 30 cerebellopontine angles and two in 10. In thirty-two (80%) the recurrent perforating arteries passed between the facial nerve and the vestibulocochlear nerve. In the thirty-two cerebellopontine angles, some recurrent perforating arteries (87.5%) were located in the external two-third part of the facial nerve and vestibulocochlear nerve in the cerebellopontine angle. In thirty-eight (95%) the vestibulocochlear nerves had contact with the anterior inferior cerebellar artery or its branches. Among them, twenty (50%) had two or more branches contacted with the vestibulocochlear nerves. CONCLUSION: These data may be helpful in the microvascular decompression surgery of the vestibulocochlear nerve, and in the radiography of cerebellopontine angle.

Adult↗

PubMedDate not supplied

Histologic study of the vestibulocochlear nerve.

The vestibulocochlear nerve was studied histologically in cross section from the brain stem to the lateral fundus of the internal within the posterior cranial fossa. The cochlear fibers were denser and darker than the vestibular. This difference created double staining of the eighth cranial nerve in the posterior cranial fossa. At the porus acusticus, the nerve fibers became myelinated. Myelin appeared on vestibular fibers more medially than on cochlear fibers. A discrete point of vestibular-cochlear separation was consistently identified in the lateral portion of the internal auditory canal near Scarpa's ganglion. These results suggest that the most reliable point for discrimination of cochlear from vestibular nerves occurs inside the internal auditory canal.

Adult↗

PubMed1988

[Changes in the sensitivity of the cornea in patients with intracerebral tumors. Studies of patients with meningioma of the cranial base and neurinoma of the trigeminal nerve and the vestibulocochlear nerve using the Draeger esthesiometer].

The center of the cornea was measured preoperatively in 29 patients suffering from intracranial tumors (acoustic neuroma, trigeminus neuroma, basal meningioma). These measurements were made with the Draeger electronic-optical esthesiometer; the results were supplemented by an analysis of tumor diameters determined by computer tomography. In each case one-half of the patients with acoustic neuromas and medial meningiomas of the wing of the sphenoid bone manifested a reduction in sensitivity at the center of the ipsilateral cornea (normal: 0.8 to 1.7 x 10(-5) N). The diameters of the sensitivity-reducing acoustic neuromas ranged from 15 mm to 45 mm. It may be deduced both from the topographic conditions at the skull base in the vicinity of the porus acusticus internus and from the conditions associated with a pressure-induced lesion of a peripheral nerve that medial acoustic neuromas as small as 10.1 mm in diameter can lead to a reduction in the conductivity of the ipsilateral trigeminal nerve. Only when they attain a diameter of 28.4 mm and when the proportions of the skull base are equally spacious do the acoustic neuromas regularly cause an ipsilateral corneal hypesthesia.

Adult↗

PubMed1990

[Quantitative analysis of glia in the facial and vestibulocochlear nerves].

Human normal vestibulocochlear and facial nerve trunks were cut off near the brain stem of the individuals who ages ranged from 24 to 93 years old. For this study, the discriminative staining method (Luxol fast blue--periodic acid-Shiff--hematoxylin triple stain) was adopted. It is admitted that the vestibulocochlear nerve medial to the internal auditory canal histologically resembles to the central nervous system in the rat. In order to confirm the fact in human, the intervening glial cells among nerve fibers were observed in the transverse section of vestibulocochlear and facial nerves. Schwann cells and microglia were observed among nerve fibers, but oligodendroglia. And the number of the glia was counted. The glial ratios related to the transverse nerve areas and the number of axons were calculated, and were examined in relation to aging. We found that there were more Schwann cells than microglia on both vestibulocochlear and facial nerves, facial nerve had more Schwann cells than vestibulocochlear nerve, and the number of Schwann cells per single myelinated fiber increased with age in the facial nerve. A quantitative study has not been included in the literature on the number of glia in the peripheral nervous system. Then, a quantitative study of human normal glial may be essential to elucidate pathogenesis regarding peripheral neuropathies, nerve injury or nerve sheath tumors as distinguished from the normal aging process.

Adult↗

PubMed1990

Nerve fiber analysis and the aging process of the vestibulocochlear nerve.

Nerve fiber analyses were performed on the human vestibulocochlear nerve stained with Luxol fast blue-periodic acid-Schiff-hematoxylin with use of a combination of an image-analyzer and a computer. The axons were counted and their transverse (cross-sectional) areas were measured in 12 individuals. The average numbers of axons in each vestibular and cochlear nerve were 17,727 and 25,098, and the average transverse areas of their axons were 4.02 and 1.79 microns 2, respectively. Amyloid bodies and intervening Schwann cells in the vestibulocochlear nerve were also counted. The average number of amyloid bodies was 246 per transverse section of the nerve and their average size was 114 microns 2. The average number of intervening Schwann cells was 1,513. Our results indicated that the transverse axonal areas of the cochlear nerve became reduced with age, while the transverse areas of the amyloid bodies in the vestibulocochlear nerve increased with age. The number of vestibular nerve fibers did not seem to change with age.

Adult↗

PubMed1995

[Distribution and origin of corpola amylacea in the vestibulocochlear nerve].

The distribution of the corpora amylacea in the vestibulocochlear nerve is very limited. We studied the relation between the number of corpora amylacea in the cochlear nerve and the aging of cochlea and developed some hypotheses on the origin of corpora amylacea. This study involved 11 subjects, 14 samples. The results were as follows. There was no relationship between the number of corpora amylacea in the cochlear nerve and aging of the cochlea. Corpora amylacea probably have no relation to cochlear disorders. However, it was reported that corpora amylacea were produced more than 10 years after the organ's obstruction. There is a possibility that corpora amylacea increased 10 years after disorders developed in the cochlear nerve. There is a neurilemma-Schwann sheath junction (NSS junction) in the vestibulocochlear nerve. Corpora amylacea characteristically exist only in the central portion of the vestibulocochlear nerve on one side of the NSS junction. There are 3 possibilities regarding the origin of corpora amylacea which include consideration of the hypothesis that the NSS junction is the point where the vestibulocochlear nerve pierces the encephal dura mater. 1) Supposing that the origin of the corpora amylacea is the vestibulocochlear nerve itself, we would expect that the oligodendrocytes which are components of the vestibulocochlear nerve to be the origin of the corpora amylacea because they exist only in the central portion of the nerve, but not in peripheral portions of the nerve. 2) Supposing that the origin of the corpora amylacea is not the vestibulocochlear nerve itself, we would expect that the perineurium from the encephal dura mater to be the origin of corpora amylacea.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1986

[An autopsy case of meningeal carcinomatosis with vestibulocochlear nerve disturbance as the first manifestation].

A 54-year-old man initially complained of frontal headache, right ear pain and tinnitus in May, 1985. This was followed by right facial palsy and hearing loss, and he was admitted to our hospital. Physical findings revealed right trigeminal nerve disturbance, left facial nerve palsy and bulbar palsy. The spinal fluid showed pleocytosis, increased protein, decreased glucose, markedly increased carcinoembryonic antigen and adenocarcinoma cells. Gastric carcinoma was revealed by an upper GI series. He was treated with chemotherapy. However, he die in August, 1985. Nodular metastases were discovered at the right internal acoustic meatus and other areas. Microscopically, signet-ring cell carcinoma had diffusely infiltrated at the subarachnoid space.

Adenocarcinoma, Mucinous↗

PubMedDate not supplied

Topographical relationship of the facial and vestibulocochlear nerves in the subarachnoid space and internal auditory canal.

PURPOSE: Our purpose was to investigate the topographical relationship of the facial and vestibulocochlear nerves from the brain stem through the internal auditory canal. METHODS: We dissected 15 formalin-fixed cadaveric heads and performed MR examinations in 35 healthy subjects in order to examine the topographical relationship of the facial and vestibulocochlear nerves. The cadaveric dissections and the in vivo MR imaging findings were compared indirectly. RESULTS: The relationship between the facial and vestibulocochlear nerves showed some variation among individuals and according to the location of the nerves within the cisterns or canal. Near the brain stem, 53% of the vestibulocochlear nerves were partially segmented on MR images. The vestibulocochlear nerve was completely divided into separate nerves only in the most lateral portion of the canal, except in three cadaveric dissections, in which separation of the superior vestibular nerve was seen near the brain stem. The facial and cochlear nerves were of similar size on 36% of the MR images. The superior vestibular nerve was larger than the inferior vestibular nerve on 81% of the MR images. CONCLUSION: The appearance of the facial and vestibulocochlear nerves was variable but followed certain consistent patterns.

Adult↗

PubMedDate not supplied

Anatomy of the facial and vestibulocochlear nerves in the internal auditory canal.

PURPOSE: To define the anatomy of the facial and vestibulocochlear nerves in the internal auditory canal on parasagittal CT scans of cadaveric specimens and to compare this anatomy with findings on in vivo T2-weighted two-dimensional fast spin-echo and three-dimensional turbo spin-echo MR images. METHODS: Thirty-eight formalin-fixed cadaveric temporal bones were examined with 1-mm-thick contiguous parasagittal CT sections to determine the anatomy of the nerves in the internal auditory canal. Ten specimens underwent limited dissection. Fourteen canals in 12 patients were examined with T2-weighted two-dimensional fast spin-echo oblique parasagittal MR imaging and 12 canals in 8 patients were examined with T2-weighted three-dimensional turbo spin-echo MR imaging. The anatomy depicted on MR images was compared with the cadaveric anatomy. RESULTS: On cadaveric specimens, the facial nerve coursed superior and anterior to the vestibulocochlear nerve as a tubular structure throughout the length of the canal. The vestibulocochlear nerve entered the canal as a tubular structure but became crescent shaped in cross section in the middle portion of the canal and separated into individual nerves only in the most lateral portion of the canal. The anatomy of the nerves differed among the specimens. Similar anatomy was demonstrated by MR imaging. CONCLUSION: The ability to define the nerves in the internal auditory canal in the parasagittal plane may provide greater sensitivity and specificity in identifying abnormalities of this anatomic structure.

Ear, Inner↗

PubMed1996

Distribution of amyloid bodies in the aged human vestibulocochlear nerve.

We tried to elucidate the localization and distribution of amyloid bodies (Corpora amylacea) in the human vestibulocochlear nerve stained with luxol fast blue-periodic acid Schiff-hematoxylin using of a combination of an image analyzing computer system and a microscope fitted with a drawing tube. After having observed each section of the vestibulocochlear nerve from the brain stem to the fundus of the internal auditory meatus, we counted the numbers of amyloid bodies in three different parts for each of three corpses, and measured the areas. We found that amyloid bodies of the vestibulocochlear nerve are concentrated to the limiting glial portion of the nerve more than to the nerve parenchyma, and amyloid bodies are not seen in the vestibulocochlear nerve peripheral to the transitional zone. Our quantitative trial proved that the amyloid body was larger in the 8th decade than in the 6th or 7th decade of life.

Aged↗

PubMedDate not supplied

Congenital malformations of the inner ear and the vestibulocochlear nerve in children with sensorineural hearing loss: evaluation with CT and MRI.

PURPOSE: The purpose of this work was to study the diagnostic value of CT and MRI in children with sensorineural hearing loss and to analyze anatomic abnormalities of the inner ear and the vestibulocochlear nerve in this patient group. METHOD: We evaluated 42 inner ears in 21 children with congenital deafness who had congenital inner ear malformations and who were candidates for cochlear implants. All patients were studied with high resolution MR and helical CT examinations. The MR study included a T2-weighted 3D fast SE sequence. We describe and tabulate the anatomic abnormalities. Special attention was given to abnormalities of the vestibulocochlear nerve. The field of view in the plane according to the length axis of the internal auditory canal (IAC) was 4 cm. Additional continuous parasagittal reformations perpendicular to the length axis of the IAC were studied with a field of view of 3 cm. RESULTS: CT and MRI allowed accurate identification of malformations of the inner ear in children with congenital deafness. We identified 99 malformations, with a majority of patients demonstrating multiple abnormalities. Common imaging findings were Mondini abnormality and Mondini variants (12/42) and fusion of the lateral or superior semicircular canal with the vestibule (12/42). MRI demonstrated in 9 of 21 patients a rudimentary or absent vestibulocochlear nerve in the auditory canal. CONCLUSION: CT and MRI are important modalities to analyze the inner ear in children who are candidates for cochlear implants. MRI with an extremely small field of view should be used to study possible abnormalities of the vestibulocochlear nerves. This may alter clinical care and allow cochlear implant placement in patients whose electrodiagnostic studies suggest that the implant should not be performed. The detailed analysis of abnormalities of the inner ear might establish prognostic factors.

Child↗

PubMed1983

Facial and vestibulocochlear nerve disease in six horses.

In 6 horses, clinical signs of illness implicated a lesion involving the facial and vestibulocochlear nerves. One horse had signs of otitis externa. Five horses had radiographic changes primarily involving periosteal bony proliferation of the stylohyoid bone at its articulation with the temporal bone. Five horses improved with antibiotic therapy. Otitis media-interna was found at necropsy of one horse.

Ampicillin↗

PubMed2005

Xenografted fetal dorsal root ganglion, embryonic stem cell and adult neural stem cell survival following implantation into the adult vestibulocochlear nerve.

Sensorineural hearing loss is a disabling condition. In the post-embryonic and adult mammalian inner ear, the regeneration of auditory hair cells, spiral ganglion neurons or their axons does not occur naturally. This decrease in excitable neurons limits the success of auditory rehabilitation. Allografts and xenografts have shown promise in the treatment of a variety of neurological diseases. Fetal dorsal root ganglion (DRG) neurons can extend functional connections in the rat spinal cord. Embryonic stem cells (ES cells) and adult neural stem cells (ANSC) have the potential to differentiate into neurons. We have implanted embryonic days (E) 13-16 fetal mouse DRGs from transgenic mouse lines that express Enhanced Green Fluorescent Protein (EGFP) or lacZ reporter genes, EGFP-expressing ES cells or lacZ-expressing ANSC into the injured vestibulocochlear nerve of adult rats and guinea pigs. Survival of the implants was assessed 2 to 4 weeks postoperatively. For further evaluation of the differentiation of the implanted ES-cells, we double labeled with the mouse-specific neuronal antibody Thy 1.2. The rats implanted with EGFP- or lacZ-expressing DRGs showed labeled DRGs after sacrifice. In addition, EGFP-positive nerve fibers were seen growing within the proximal nerve. The results from the EGFP ES cells and lacZ ANSC revealed reporter-expressing cells at the site of injection in the vestibulocochlear nerve of the host rats and guinea pigs but also within the brain stem. Thy 1.2 profiles were seen among the EGFP ES cells within the 8th cranial nerve. The findings of this study indicate that the vestibulocochlear nerve of adult rats and guinea pigs will support xenotransplants of embryonic DRG, ES cells and ANSC. This may have future clinical applicability in recreating a neuronal conduit following neuronal injury between the inner ear and the central nervous system (CNS).

Animals↗

PubMed2001

Microvascular decompression of the vestibulocochlear nerve for disabling positional vertigo: the House Ear Clinic experience.

OBJECTIVE: To review characteristics of and outcome in patients undergoing microvascular decompression of the vestibulocochlear nerve. Patients studied had a diagnosis of disabling positional vertigo caused by a vascular loop compressing the VIIIth cranial nerve. STUDY DESIGN: Retrospective chart review and telephone interview. SETTING: Private practice tertiary neurotologic referral center. PATIENTS: Twenty patients with disabling positional vertigo underwent 25 retrosigmoid craniotomies for microvascular decompression between November 1990 and June 1999. The 4 men and 16 women ranged in age from 30 to 71 years (mean age, 46 yr). MAIN OUTCOME MEASURES: Charts were reviewed and patients were contacted by telephone and asked to rate severity of symptoms (tinnitus and dizziness) on a 4-point scale (none = 1, mild = 2, moderate = 3, and severe = 4) before and after surgery. They were also asked to rate their overall disability from their symptoms on the six-point scale established by the American Academy of Otolaryngology-Head and Neck Surgery. Preoperative and postoperative four-frequency (500 Hz, 1 kHz, 2 kHz, and 4 kHz) pure-tone average and speech discrimination scores were calculated and compared. Complications of surgery are also reported. RESULTS: Postoperative tinnitus score and dizziness score showed significant improvement from preoperative scores (p < or = 0.047 and p < or = 0.001, respectively), with 80% of patients improved in dizziness rating; 85% improved in their overall disability rating, and the difference from preoperative to postoperative was significant (p < or = 0.001). The mean postoperative pure-tone averages (15.4 dB) and speech discrimination scores (99%) did not differ from preoperative scores (11.9 dB and 98%). One patient lost all vestibular function in the operated ear (hearing remained intact) as the only complication of surgery. When asked, 83% of patients responded that they would have the surgery again. CONCLUSIONS: Diagnosing disabling positional vertigo secondary to vascular compression of the VIIIth cranial nerve remains the clinical challenge; a clear history plus air-contrast computed tomographic or magnetic resonance imaging make the diagnosis. Microvascular decompression of the vestibulocochlear nerve is a safe and effective operation for these carefully selected patients.

Adult↗

PubMed2000

Topography of the vestibulocochlear nerve.

OBJECTIVE: The terms superior vestibular nerve and inferior vestibular nerve have been used in the field of neurosurgery to indicate anatomically the two respective vestibular components of the vestibulocochlear nerve. To reappraise the aptness of this terminology, fascicular patterns and the anatomic relationship of the vestibular and cochlear components were examined. METHODS: Twenty vestibulocochlear nerve specimens were obtained from cadavers. The nerves were excised, with care taken to sustain their spatial relationships, then embedded in paraffin blocks and cross sectioned in 10-microm-thick slices. Serial cross sections were stained and examined with a light microscope. RESULTS: The vestibular component was separated into two parts only at the lateral fundus of the internal auditory canal, lateral to the vestibular ganglion. In the internal auditory canal of all specimens, the vestibular component was represented by numerous fascicles. Around the porus acusticus, the fascicular pattern among the specimens was diverse: 13 of the 20 specimens were still polyfascicular, 4 specimens consisted of two large, distinct fascicles, and, in the remaining 3 specimens, a portion of the vestibular fascicles had fused with the cochlear component. Near the root entry zone, all vestibular fascicles fused and merged with the cochlear nerve to form a single trunk. CONCLUSION: There was no evidence to support the anatomic correctness of specifying the superior and inferior vestibular nerves, except in the lateral fundus of the internal auditory canal.

Brain Stem↗

PubMed2000

Comparison of a T2* w. 3D CISS and a T2 w. 3D turbo spin echo sequence for the anatomical study of facial and vestibulocochlear nerves.

Thirty healthy volunteers were examined with a T2* w. 3D CISS and a T2 w. 3D turbo spin echo (TSE) sequence in order to compare the facial and vestibulocochlear nerve detectability in the cerebellopontine angle and the internal auditory canal. CISS was significantly better than 3D TSE for nerve detectability in the cerebellopontine angle and equally as good as 3D TSE in the internal auditory canal. We would therefore recommend the inclusion of CISS in an MR imaging protocol of the facial and vestibulocochlear nerves.

Adolescent↗

PubMed2000

Neurosyphilis as a cause of facial and vestibulocochlear nerve dysfunction: MR imaging features.

The prevalence of syphilis increased for several decades before the mid-1990s in the United States, particularly in the southern states. We report a case of neurosyphilis causing bilateral facial and vestibulocochlear nerve dysfunction in which the diagnosis was not initially suspected based on the patient's demographics and history. The MR imaging features helped to make the diagnosis in this case and to exclude other possible causes of multiple cranial nerve dysfunction in this patient. Hearing loss associated with neurosyphilis is one of the few treatable forms of progressive hearing loss, and it is essential that a diagnosis of neurosyphilis be made expeditiously.

Facial Nerve↗

PubMed2002

Three-dimensional fast recovery fast spin-echo imaging of the inner ear and the vestibulocochlear nerve.

The aim of this study was to assess the performance of three-dimensional fast recovery fast spin-echo (3DFRFSE) for imaging of the inner ear as well as the facial and vestibulocochlear nerves. We evaluated 3DFRFSE sequences, comparing it with 3D fast spin-echo (3DFSE) in a water phantom and in 12 normal volunteers. We also examined 66 patients using 3DFRFSE sequence and assessed the visualization of their pathologies. In a water phantom study, signal intensity (SI) on 3DFRFSE was higher than that on 3DFSE at the same TR ranging from 1,500 to 6,000 ms. In normal volunteers, 3DFRFSE with TR of 2,800 ms showed comparable SI, and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) superior to those on 3DFSE with TR of 5,000 ms. In clinical setting, 3DFRFSE was useful in demonstrating anatomic details in the labyrinth and pathologic findings of inner ear. The 3DFRFSE can provide high-resolution heavily T2-weighted images (T2WI) with shorter scan time than 3DFSE without significant disadvantage. The 3DFRFSE is a beneficial technique for evaluation of lesions in the inner ear as well as the facial and vestibulocochlear nerves.

Ear, Inner↗