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Biomedical subjects

I Sando

Publications and source records attributed to I Sando.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Noise-induced hearing loss. A human temporal bone case report.

The histopathology of a case of profound hearing loss which seemed to be induced by noise exposure (explosions and drillings in a gold mine) is reported. The patient's only residual hearing was 250 Hz at 90 dB SPL in the right ear. The major histopathological findings were as follows: Bilateral absence or collapse of Corti's organ was observed in the middle and basal turns of the cochlea; however, in the remaining area (approximately 6.0 mm in range in the apical portion of the cochlea) Corti's organ was well-preserved with a moderate loss in number or atrophy of the hair cells. Bilateral marked decrease of the cochlear nerve was noted in the middle and basal turns; however, the nerve was well-preserved in the remaining apical portion (approximately 6.0 mm in range) of the cochlea. These pathological findings were somewhat less severe in the right cochlea than in the left. In general, there was good correlation between the profound hearing loss and the extensive pathological findings in Corti's organ. The residual hearing in the right ear would seem to be explained by the less severe pathological changes found in the apical portion of the right cochlea than in the left cochlea. In addition to noise exposure, other possible etiological factors contributing to this hearing loss are discussed. These include diabetes mellitus and presbycusis.

Aged↗
PubMedDate not supplied

Temporal bone histopathology in deafness due to cryptococcal meningitis.

This paper reports on a patient who survived an attack of cryptococcal meningitis eight years prior to his death. A bilateral sensorineural hearing loss had been noted a short time before the patient was admitted to the hospital, and was the only complication after he recovered from the disease. Histopathologic study of the temporal bones showed a similar pattern of pathology in both ears, the most striking finding being a severe loss of spiral ganglion cells in Rosenthal's canal, and of cochlear nerve fibers in the osseous spiral lamina and internal auditory meatus. The vestibular nerve was mostly free from pathology. The organ of Corti was atrophic but the hair cell population appeared to be almost normal. A slight number of cryptococci were observed in limited areas of the cochlear and the saccular nerves in the internal auditory meatus. The severe pathology of the cochlear nerve was compatible with audiologic evaluations, which pointed to a retrocochlear lesion. Thus, this case demonstrates some characteristic aspects of cryptococcal infection of the temporal bone: The primary site of invasion was the cochlear nerve in the internal auditory meatus and the modiolus, leading to the loss of ganglion cells and nerve fibers, while the vestibular nerve appears to have been resistant to infection.

Cochlear Nerve↗
PubMedDate not supplied

Branch of the singular nerve (posterior ampullary nerve) in the otic capsule.

The frequency of occurrence, location and course of the branch of the singular nerve in the otic capsule in man was investigated by examining the histological sections of 223 human temporal bones. In the proximal portion near the internal auditory meatus the branch of the singular nerve was observed in 194 bones (87%), and was seen to join the main trunk of the singular nerve in 181 of those bones. In the distal portion near the posterior semicircular canal ampulla in 58 bones (26%) and in 45 of those bones it was seen to arise directly from the main trunk of the singular nerve. In 13 bones the branch was seen taking its course in the otic capsule independently from the main trunk all the way to the posterior canal crista. The accessory portion of the branch of the singular nerve reached the dura mater of the posterior cranial fossa near the internal auditory meatus in 11 of 223 bones.

Adolescent↗
PubMedDate not supplied

Course and contents of the paravestibular canaliculus.

The purpose of this study is to describe the anatomy of the paravestibular canaliculus (PVC) in detail, especially its course in relation to the vestibular aqueduct (VA) and its vascular contents. Serial horizontal sections of 20 normal human temporal bones were stained either with hematoxylin and eosin, by Verhoeff-van Gieson's method, or by Mallorys method, and studied under the light microscope. Graphic reconstruction of the VA and the PVC was performed in some of the cases. In this study, the following new anatomical information on the common course and vascular contents of the PVC was obtained: 1) two PVC are present in the area near the vestibular orifice of the VA; 2) the PVC merges with the VA in the area near its cranial orifice without any particular branching, and does not enter the posterior cranial fosa; 3) veins course through the entire length of the PVC whereas arteries course only through the posterior cranial fossa side of the PVC. It appears that veins are the major contents of the PVC and that these veins represent the main venous drainage system from the vestibule. It also appears that arteries in the PVC supply the blood from the posterior cranial fossa mainly to the PVC itself.

Arteries↗
PubMedDate not supplied

Temporal bone histopathology of necrotizing external otitis. A case report.

Histopathological examination of the temporal bone of an individual with necrotizing external otitis revealed severe inflammation with necrosis in the subcutaneous granulation tissue in the external auditory canal. Erosion of the bony walls of the canal had created a defect in the anterior wall, through which infection spread to the preauricular region. The lateral part of the middle ear cavity was also filled with granulation tissue and purulent exudate. A dehiscence of the horizontal portion of the facial canal had apparently allowed spread of an inflammatory round cell infiltrate along the facial nerve up to the fundus of the internal auditory canal. The only evidence of inner ear pathology was the presence of eosinophilic fluid material in the perilymphatic spaces of the labyrinth. A review of other reports of cases of necrotizing external otitis seems to show that this is the only instance of this disease in which infection spread from the external canal through the tympanic membrane to the middle ear and thence to the internal auditory canal.

Aged↗
PubMedDate not supplied

Microfissure in the oval window area.

Examination of 331 human temporal bones revealed the presence of microfissure in the oval window area in 25%. The youngest temporal bone in which the microfissure was observed was from a child eight years old and the oldest temporal bone was from an individual 102 years old. It appears that hte microfissure in this area occurs extremely rarely before 10 years of age, that it begins to be observed after the age of 10, and that the incidence of this fissure increases sharply at about age 40. In 61% of the bones in which the microfissure was observed, it was present both superior and inferior to the oval window in almost the same vertical plane. In none of the bones, however, did it extend beyond the annular ligament to the footplate. The histological appearance of the microfissure in this area was quite similar to that of the microfissure between the posterior canal ampulla and round window niche, although the latter appeared to be wider in general. The histogenesis of the microfissure is still unknown, but upon careful analysis of the results of this study and literature review, the authors consider nontraumatic spontaneous fracture by mechanical stress to be the most probable explanation for its occurrence. Possible clinical significance of the microfissure is also discussed.

Adolescent↗
PubMedDate not supplied

Spatial occupancy of vessels and facial nerve in the facial canal.

The vascularity and spatial relationships of the content of the labyrinthine portion of the facial canal were studied by measuring the diameters of arteries, the areas of the arteries, veins, facial nerve, and canal; and by expressing these areas as percentage of the areas of the facial canal facial nerve. These results were compared for each of these segments of the facial canal. Using temporal bone sections which contained transverse or oblique sections of the three representative (labyrinthine, tympanic , and mastoid) portions of the facial canal, the size of the largest artery, and the area of the sectioned vessels, facial nerve, and facial canal were measured. Relative values of measured areas were calculated as an index of spatial occupancy of vessels and facial nerve in the canal. By comparing these results in three portions, we could demonstrate that, in the labyrinthine portion, the internal diameter of the main artery was less than four tenths of the diameter of the arteries in the other portions, and that the ratio of spatial occupancy of the vessels to the canal and to the nerve in the labyrinthine portion was extremely small compared with that in the other two portions. We also found that the labyrinthine and tympanic portions of the canal have less extra space for the nerve than does the mastoid portion. Considering both the vascularity of the three portions of the facial canal, and the spatial relationships of elements in the canal in each of the three segments of the canal, we feel that the facial nerve in the labyrinthine portion of the facial canal is indeed anatomically the most vulnerable portion of the nerve in its course through the temporal bone.

Arteries↗
PubMedDate not supplied

Inner ear pathology following injury to the eighth cranial nerve and the labyrinthine artery.

Inner ear pathology following surgical sectioning of the eighth cranial nerve and labyrinthine artery in humans is compared histologically to the pathology observed following severance of the eighth cranial nerve. The case in which both the eighth cranial nerve and the labyrinthine artery were surgically severed revealed severe pathologic changes in the cochlea, including complete loss of the organ of Corti and moderate pathologic changes in the fairly well-preserved vestibular end-organs. Interestingly, the endolymphatic sac appeared to be normal. However, the second case in which the eighth cranial nerve was sectioned but the labyrinthine artery was preserved revealed the organ of Corti and vestibular end-organs to be well preserved and normal. These findings suggest that the blood supply from the labyrinthine artery plays a major role in maintaining most of the structures in the inner ear except for the endolymphatic sac, and that the vestibular end-organs are more resistant than the organ of Corti to the effects of damage of the labyrinthine artery.

Arteries↗
PubMedDate not supplied

Endolymphatic duct and sac in patients with Meniere's disease. A temporal bone histopathological study.

The endolymphatic ducts and sacs of 25 temporal bones with idiopathic endolymphatic hydrops from individuals with Meniere's disease were studied and compared with the same number of control bones without endolymphatic hydrops from individuals with no premortem history of otologic disease. The control bones were selected so that the sizes of their vestibular aqueducts matched those temporal bones from individuals with Meniere's disease. The endolymphatic ducts and sacs of all bones were studied by the medial view graphic reconstruction method and/or histological observation under a light microscope. In the endolymphatic duct and sac of many of the temporal bones from patients with Meniere's disease were noted a diminution of the width of the endolymphatic duct in its isthmus portion, an increase in the area of the collapsed lumen of the endolymphatic sac, fibrotic changes in the perisaccular loose connective tissue, and an increase in the quantity of intraluminal eosinophilic material. The frequencies with which these pathological findings were noted in bones from individuals with Meniere's disease and in control bones were statistically significantly different. No significant differences were observed under light microscopic study between these two groups with regard to the condition of the epithelial cells, the degree of rugosity of the endolymphatic sac, or the appearance of melanin-like pigmentation of hyalinization in the perisaccular connective tissue.

Adult↗
PubMedDate not supplied

Congenital anomalies of the inner ear.

This study investigated congenital anomalies occurring in the inner ear, with particular attention to their features, localizations, and frequencies. Seventy-seven human temporal bones obtained from 53 individuals, aged one day to 39 years, each of whom had anomalies of the external ear, middle ear, and/or inner ear, were used for this study. The temporal bones had been removed at autopsy, fixed, dehydrated, embedded in celloidin, and sectioned horizontally or vertically at 20 microns. Every tenth horizontal section or every 20th vertical section was stained with hematoxylin and eosin, mounted, and studied under a light microscope. There were 206 inner ear anomalies (117 in the vestibular system, 79 in the cochlea, 10 in the internal auditory meatus) in the 51 bones studied. Fifty-four different features of anomalies were present at 33 different locations in the inner ear. The most frequent anomalies observed were shortened cochlea (23 bones), enlarged vestibule (17 bones), wide cochlear aqueduct (16 bones), absence of lateral semicircular canal (14 bones), and large osseous lateral semicircular canal (10 bones). The most common site of inner ear anomalies was thus the lateral semicircular canal, which was involved in 46 of the 206 anomalies observed; the anomalies in this organ were variable in type. The implications of inner ear anomalies are discussed as they relate to fetal development, inner ear dysfunction, and clinical interpretation of polytomographic studies.

Abnormalities, Multiple↗
PubMedDate not supplied

Histopathology of otitis media in infants with cleft and high-arched palates.

The middle ear and the bony and cartilaginous portions of the eustachian tube (ET) were studied histopathologically in 20 temporal bones from 19 infants, aged 45 minutes to 12 months. Otitis media (OM) was observed in 17 of 20 bones, and 16 bones with OM had an effusion. Otitis media was more severe in the ears of cleft palate infants compared to those with high-arched palates. Inflammation was present in the bony portion of the ET in 15 of 17 temporal bones with OM, but appeared to be less marked than that present in the middle ear. In addition, inflammation of the cartilaginous portion of the ET appeared to be less severe than in its bony portion. Inflammation of the middle ear and the ET appeared to be more pronounced in older infants, particularly in those with cleft palates.

Cleft Palate↗
PubMedDate not supplied

Pneumatization and thickness of the petrous bone in patients with Meniere's disease. A histopathological study.

Histological evaluations were made of the degree of pneumatization and thickness of the petrous bone surrounding the vestibular aqueduct, and of the relationships of these parameters to the condition of the vestibular aqueduct in 27 temporal bones with idiopathic endolymphatic hydrops from individuals with Meniere's disease. The results were compared with those from the same parameters in 79 control temporal bones without endolymphatic hydrops from individuals who had no premortem history of otologic disease. Pneumatization of the temporal bones of patients with Meniere's disease was in most cases less than that of control temporal bones; this difference was statistically significant. Poor pneumatization of the temporal bones of individuals with Meniere's disease appeared to be closely associated with hypoplasia of the vestibular aqueduct, an anatomical feature of many individuals with Meniere's disease. However, no statistically significant difference could be found between the thickness of the petrous bone in the periaqueductal region in bones of patients with Meniere's disease and this parameter in control bones.

Adult↗
PubMedDate not supplied

Vascularity of endolymphatic sac in Meniere's disease. A histopathological study.

The vascularity of the endolymphatic sac (ES) in the vestibular aqueduct (VA) and of periaqueductal bony channels was studied in 18 temporal bones from patients with Meniere's disease and in the same number of control bones with no endolymphatic hydrops and no premortem history of otologic disease. The control bones were selected on the basis of having VAs of the same sizes as the hydropic bones. This was important in order to eliminate any possibility that differences in degree of vascularity of the ES could have been due simply to differences in the degree of development of the VA. All specimens were sectioned and stained with hematoxylin and eosin. The ES of each bone was reconstructed two-dimensionally by the medial view graphic reconstruction method, and its vascularity was studied histologically under a light microscope. There were fewer and smaller blood vessels in the ESs of bones from individuals with Meniere's disease than in the ESs of control bones. This was particularly true in the richly rugose and the cranial orifice portions of the sac. However, no significant differences were recognized in the degree of vascularity of the periaqueductal bony channels between control and Meniere's disease bones.

Adult↗
PubMedDate not supplied

Paravestibular canaliculus in Meniere's disease. A histopathological study.

The paravestibular canaliculus (PVC) and its contents were studied in 27 temporal bones from individuals with Meniere's disease and in the same number of controls. The specimens were examined by the medial view graphic reconstruction method and/or histologically under a light microscope. In most of these bones (88.9% of controls and 85.2% of Meniere's bones) only one PVC was noted; in the remaining bones (11.1% of controls and 14.8% of Meniere's bones) two PVCs were recognized. Most of the PVCs (88.9%) in both control and Meniere's bones were located in the petrous bone anterolateral to the vestibular aqueduct (VA). In one third of both control and Meniere's bones the PVC extended below the inferior margin of the posterior semicircular canal. In 74.1% of the Meniere's bones the PVCs were noted to exit directly to the posterior cranial fossa, whereas such a course was present in only 40.7% of controls. The difference in this parameter between control and Meniere's disease bones is statically significant and appears to be related to the size of the VA. The length of the PVC, however, seems to be independent of both the size of the VA and the degree of development (thickness) of the petrous bones surrounding the PVC. In four Meniere's bones a part of the main vein in the PVC was absent; this was never observed in a control bone. We found no other evidence in this study to link the function or anatomy of the PVC to Meniere's disease.

Aged↗
PubMedDate not supplied

Lymphoma invading the anterior eustachian tube. Temporal bone histopathology of functional tubal obstruction.

The temporal bones of a man with poorly differentiated lymphocytic lymphoma, who had had a bilateral conductive hearing loss and incomplete left-sided facial palsy, were obtained. Sections were prepared for histologic study by staining with hematoxylin and eosin and were examined under the light microscope. The left temporal bone showed marked tumor cell involvement, not only of the lateral part of the cartilaginous portion of the eustachian tube (ET) where the tensor veli palatini muscle had been partially destroyed, but also in the anterior part of the temporal bone. A serous middle ear effusion was present, but the lumen of the ET was unaffected by tumor or inflammation. The pathological findings in the right temporal bone were similar to those in the left, although the cartilaginous part of the ET and its surrounding structures were not available for study. The pathogenesis of otitis media with effusion appeared to be secondary to functional ET obstruction, due to the dysfunction of the tensor veli palatini muscle as a result of the tumor destruction. This case is the first to be reported in which functional ET obstruction, secondary to tumor invasion of the active muscle dilator of the ET, has been histologically confirmed.

Adult↗
PubMedDate not supplied

A method for the histopathological analysis of the temporal bone and the eustachian tube and its accessory structures.

A very important contribution to the study of otitis media, one of the diseases most often seen in pediatric patients, is the collection, processing, and study of the specimens of the temporal bone and the entire eustachian tube. During the last few years, we have collected, processed, and studied 100 such specimens, and through these experiences our technique has become refined. We now have some important suggestions for otologists interested in the histological study of otitis media as well as in the pathology of the eustachian tube and its relation to middle ear abnormalities. This report details the most successful method for the study of eustachian tube abnormalities and their relationship to middle ear effusion.

Dissection↗