Vestibular Membranous Labyrinth Research Articles

Vestibular Aging Process from 3D Physiological Imaging of the Membranous Labyrinth

There is no three-dimensional (3D) technique to study the microanatomical structures of the in vivo 3D vestibular membranous labyrinth. Recent two MRI methods using a contrast agent can only depict the low-resolution imaging of endolymphatic hydrops. Therefore, we provide the new precise volume rendering algorithms to create the in vivo 3D vestibular membranous labyrinth images from high-resolution temporal bone low-dose CT data. We also ascertain whether the created 3D microstructure images are reliable in anatomical findings. Secondary, we will analyze the age-related changes of the vestibular membranous labyrinth. These created 3D membranous vestibular images were almost consistent with the appearance, dimensions, areas, and angles from those acquired in previous histological works. The age-related image changes showed the enlarged saccule in females, the enlarged utricle in males, and the dilated tendency of the lateral semicircular duct. These results may correlate to the findings of the previous physiological works on cervical and ocular vestibular evoked myogenic potentials, and gait studies. The age-related balance disorders may be associated with the enlargement of each membranous organ in the vestibule. This new imaging technique now enables visualizing microanatomical changes in the in vivo membranous vestibulum, and these created 3D images may suggest physiological information.

Histopathological changes to the peripheral vestibular system following meningitic labyrinthitis.

ObjectiveWhile cochlear ossification is a common sequalae of meningitic labyrinthitis, less is known about the effects of meningitis on peripheral vestibular end organs. Herein, we investigate histopathologic changes in the peripheral vestibular system and cochlea in patients with a history of meningitic labyrinthitis.MethodsTemporal bone (TB) specimens from patients with a history of meningitis were evaluated and compared to age‐matched controls. Specimens were evaluated by light microscopy and assessed for qualitative changes, including the presence of vestibular and/or cochlear endolymphatic hydrops, presence and location of inflammatory cells, new bone formation, and labyrinthitis ossificans; and quantitative changes, including Scarpa's ganglion neuron (ScGN) and spiral ganglion neuron (SGN) counts.ResultsFifteen TB from 10 individuals met inclusion and exclusion criteria. Presence of inflammatory cells and fibrous tissue was found in 5 TB. Of these, evidence of labyrinthitis ossificans was found in 2 TB. In the peripheral vestibular system, mild to severe degeneration of the vestibular membranous labyrinth was identified in 60% of cases (n = 9 TBs). There was a 21.2% decrease (range, 3%‐64%) in the mean total count of ScGN in patients with meningitis, compared to age‐matched controls. In the cochlea, there was a 45% decrease (range, 25.3%‐80.9%) in the mean total count of SGN compared to age‐matched controls (n = 14 TBs).ConclusionsOtopathologic analysis of TB from patients with a history of meningitic labyrinthitis demonstrated distinct peripheral vestibular changes. Future research may help to delineate potential mechanisms for the observed otopathologic changes following meningitis.Level of EvidenceN/A

Peripheral Vestibular System Histopathologic Changes following Head Injury without Temporal Bone Fracture.

Vestibular symptoms such as dizziness and vertigo are common after head injury and may be due to trauma to the peripheral vestibular system. The pathophysiology of peripheral vestibular symptoms following head injury without temporal bone (TB) fracture, however, is not well understood. Herein, we investigate the histopathology of the peripheral vestibular system of patients who sustained head injury without a TB fracture. Otopathology study. Otopathology laboratory. TB of subjects with a history of head injury without TB fractures were included and evaluated by light microscopy. Specimens were assessed for qualitative and quantitative characteristics, such as number of Scarpa's ganglion cells in the superior and inferior vestibular nerves, vestibular hair cell and/or dendrite degeneration in vestibular end organs, presence of vestibular hydrops, and obstruction of the endolymphatic duct. Five cases (n = 5 TBs) had evidence of vestibular pathology. There was a decrease of 48.6% (range, 40%-59%) in the mean count of Scarpa's ganglion cells as compared with that of normative historical age-matched controls. Moderate to severe degeneration of the vestibular membranous labyrinth was identified in the posterior, superior, and lateral canals in several cases (50%, n = 4 TBs). The maculae utriculi and sacculi showed mild to severe degeneration in 2 cases. Additional findings include vestibular hydrops (25%, n = 2 TBs) and blockage of the endolymphatic duct (n = 1 TB). Otopathologic analysis of patients with a history of head injury without TB fracture demonstrated peripheral vestibular otopathology. Future studies are necessary to determine if otopathology findings are directly attributable to head injury.

Herniation of the Membranous Labyrinth Into the Horizontal Semicircular Canal Is Correlated With Impaired Caloric Response in Ménière’s Disease

Canal paresis of the horizontal semicircular canal in Ménière's disease is a frequent finding. Endolymphatic hydrops is the single most characteristic morphologic finding in Ménière's disease. However, the relationship between endolymphatic hydrops and canal paresis is still not elucidated. We used magnetic resonance imaging to visualize herniation of parts of the vestibular membranous labyrinth into the horizontal semicircular canal and correlated this morphologic feature with the caloric function of the horizontal semicircular canal. Patients who showed herniation into the horizontal canal had a significantly impaired caloric function when compared with patients without this morphologic feature. Herniation into the semicircular canal may be the morphologic correlate for impaired caloric response in patients with Ménière's disease.

The Role of 3-Canal Biomechanics in Angular Motion Transduction by the Human Vestibular Labyrinth

The present work examines the role of the complex geometry of the human vestibular membranous labyrinth in the process of angular motion transduction by the semicircular canals. A morphologically descriptive mathematical model was constructed to address the biomechanical origins of temporal signal processing and directional coding in determining the inputs to the brain. The geometrical model was developed based on shrinkage-corrected temporal bone sections using a segmentation/data-fitting procedure. Endolymph fluid dynamics within the 3-canal labyrinth was modeled using an asymptotic form of the Navier-Stokes equations and solved to estimate endolymph and cupulae volume displacements. The geometrical model was manipulated to study the role of major morphological features on directional and temporal coding. Anatomical results show that the bony osseous canals provide reasonable estimates of the orientation of the delicate membranous canals--the two differed by only 3.48 +/- 1.89 degrees . Biomechanical results show that the maximal response directions are distinct from the anatomical canal planes, but can be closely approximated by fitting a flat plane to the centerline of the canal of interest and weighting each location along the centerline with the inverse of the cross-sectional area squared. Vector cross-products of these maximal response directions, in turn, determine the null planes and prime directions that transmit the direction of angular motion to the brain as three independent directional channels associated with the nerve bundles. Finally, parameter studies indicate that changes in canal cross-sectional area and shape only moderately affect canal temporal and directional coding, while three-canal orientation is critical to directional coding.

11 beta-Hydroxysteroid dehydrogenase in the rat inner ear.

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) was demonstrated specifically in the spiral ligament of the cochlear membranous labyrinth by enzyme assay, Western blotting, and immunocytochemistry. Other cochlear regions and the vestibular membranous labyrinth were devoid of 11 beta-HSD. Spiral ligament 11 beta-HSD exerted predominantly an oxidative activity and was NADP specific, which is similar to 11 beta-HSD in most other tissues. 11 beta-HSD was colocalized with mineralocorticoid and glucocorticoid steroid receptors in the spiral ligament. 11 beta-HSD may control steroid binding to these inner ear steroid receptors and, in addition, may regulate steroid receptor binding in the adjacent stria vascularis in paracrine fashion.

Viruses and vestibular neuritis: review of human and animal studies.

There is increasing evidence in man and animals that several human viruses can damage the vestibular labyrinth. Clinical and serologic studies of patients with vestibular neuritis suggest that the viruses may play a role in the pathogenesis of this disease. Temporal bone studies of patients dying after vestibular neuritis have found maximal damage in the distal branches of the vestibular nerve. These changes are felt to be consistent with a viral etiology. No satisfactory animal viral model of vestibular neuritis currently exists. However, animal studies have demonstrated that several human viruses including rubeola, herpes simplex, reovirus, mouse and guinea pig cytomegalovirus, and neurotropic strains of influenza A and mumps virus, can infect the vestibular nerve and the vestibular membranous labyrinth.

Toward modeling a dynamic biological neural network

Mammalian macular endorgans are linear bioaccelerometers located in the vestibular membranous labyrinth of the inner ear. In this paper, the organization of the endorgan is interpreted on physical and engineering principles. This is a necessary prerequisite to mathematical and symbolic modeling of information processing by the macular neural network. Mathematical notations that describe the functioning system were used to produce a novel, symbolic model. The model is six-tiered and is constructed to mimic the neural system. Initial simulations show that the network functions best when some of the detecting elements (type I hair cells) are excitatory and others (type II hair cells) are weakly inhibitory. The simulations also illustrate the importance of disinhibition of receptors located in the third tier in shaping nerve discharge patterns at the sixth tier in the model system.

Fistulae in the membranous labyrinth.

Fistulization at various parts of the membranous labyrinth has been currently in use as one of the treatments for the symptoms of Meniere's disease. The present report concerns our experience with membranous fistulae in experimental animal ears with and without manifestation of endolymphatic hydrops. The materials presented are mostly new; however, our previous data are also incorporated in order to bring this issue into better perspective. The first part describes the nonproduction aspect of endolymphatic hydrops in the rat, chinchilla, and squirrel monkey after obliteration of the endolymphatic duct in relation to the occurrence of spontaneous fistulae. The second part describes surgical fistulization of the vestibular membranous labyrinth and cochlear duct in order to prevent or control development of endolymphatic hydrops in the guinea pig, the species in which hydrops can be produced consistently. These results are tabulated and analyzed in terms of the pathological consequences that can be expected in performing fistulization of the membranous labyrinths in animals as well as in humans.

Inner ear changes in the ferret model for Reye's syndrome

The acute effects of influenza B, aspirin, and hyperammonemia on the inner ear were examined using the ferret model for Reye's syndrome. Histopathologic examination revealed varying degrees of vacuolization in both the sensory and nonsensory endolymphatic tissues of the cochlear and vestibular membranous labyrinth. The secretory epithelial cells of the stria vascularis and the vestibular dark cells appeared to be more severely affected, as demonstrated by the presence of an extensive number of intracytoplasmic vacuoles. The cells of the perilymphatic tissues appeared to be unaltered. Although all neuroepithelial regions of the inner ear appeared to be altered, an unexpected observation was that only the inner hair cells of the organ of Corti were pathologically affected. These results suggest that metabolic and virus-induced derangements may alter inner ear microhomeostasis in patients with Reye's syndrome and may potentially result in loss of hearing in such patients.

The Structure of the Utricular Wall in Albino Guinea Pigs

The morphological details of the utricular wall of albino guinea pigs are described. Light and electronmicroscopy in this study revealed that the albino utricle consists of different types of epithelial cells, e.g. specialized and non-specialized epithelial cells and perimacular epithelial cells, which are located in well defined areas. The specialized cells are characterized by the formation of elaborate membrane infoldings and by the abundance of large mitochondria. They correspond to so-called "dark cells" and are found in the greater part of the utricular wall facing the bony wall, whereas the non-specialized cells are found in the inferior wall adjacent to the membrana limitans. In view of the presence of the membrana limitans and the distribution pattern of the specialized cells, it is postulated that perilymph surrounding the vestibular membranous labyrinth might be different in nature and source from that filling the vestibular cisterna.

Ultrastructure of vestibular membranous labyrinth in 2 cases with vertigo due to inner ear origin

Ultrastructure of vestibular membranous labyrinth in 2 cases with vertigo due to inner ear origin

Bibliographical survey of vestibular membranous labyrinth studies by the transmission electron microscope

Bibliographical survey of vestibular membranous labyrinth studies by the transmission electron microscope

ELECTRON MICROSCOPIC STUDIES ON THE VESTIBULAR MEMBRANOUS LABYRINTH

The vestibular membranous labyrinth of the guinea pig and the rabbit has been studied by electron microscopy.1) Normal structure of the epithelium of the Planum semilunatum is as follows :The simple epithelium contained many mitochondria, well-developed rough-surfaced endoplasmic reticulum, vacuoles, Golgi complexes and multivesicular body-like structures.Microvilli-like processes were found on the surface facing endolymph.In the basal part of the epithelium the plasma membrane was deeply infolded into the basal portion of the cytoplasm forming a complex doublemembrane. Between the basal infolding a great number of mitochondria were found.The features of the ultrastructure resembled closely to those found in the kidney tubules and choroid plexus.These findings suggest that this epithelium plays significant role in the water transport in the labyrinth.2) Two kinds of nerve endings were found in the hair cell of the rabbit's Crista ampullaris. One is packed with vesicles 300-500A in diameter (granulated nerve ending) and the other with few granules (non-granulated nerve ending).After electrical stimulation of the 8 th nervesubmicroscopic changes were observed on the granulated nerve endings. With stimuli of 200 pulses per second for 10 minutes a decrease in the number of synaptic vesicles was observed. It may be suggested that these are efferent nerve endings.However, more substantial evidence may be needed to distinguish the efferent from the afferent endings.3) There were found pigment cells and pigment granules in the epithelium of the utricle and the saccule, the epithelium of the Crista ampullaris and the portion of the subepithelium of the Planum semilunatum. These cells and granules are considered melanocytes and melanin. Melanin granules with a diameter 0.3_??_0.7 showed strong electron density. Melanocytes contained a few mitochondria.4) In the rabbit's sensory hair three types of stereocilia were distinguished; 1) a large one (0.4μin diameter), 2) a fused one (stereocilia and stereocilia) and 3) another fused one (stereocilia and kinocilia).

The capillaries of the vestibular membranous labyrinth in the guinea pig

The LaryngoscopeVolume 63, Issue 2 p. 87-104 Article The capillaries of the vestibular membranous labyrinth in the guinea pig† Catherine A. Smith Ph.D., Catherine A. Smith Ph.D. St. Louis, Mo.Search for more papers by this author Catherine A. Smith Ph.D., Catherine A. Smith Ph.D. St. Louis, Mo.Search for more papers by this author First published: February 1953 https://doi.org/10.1288/00005537-195302000-00001Citations: 28 † From the Department of Otolaryngology, Washington University School of Medicine, St. Louis, Mo. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume63, Issue2February 1953Pages 87-104 RelatedInformation