Cases reported "Presbycusis"

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1/4. Histopathological observations of presbycusis.

    temporal bone histopathology of 17 aged patients who had spontaneous and gradually progressive bilateral sensorineural hearing losses associated with aging was studied. Six cases in the present material showed the gradually sloping audiometric curve; nine cases, abrupt high tone hearing loss; and two cases, the flat audiometric curve. The most prominent histopathological change in the inner ear was a decrease in the population of the spiral ganglion cells. However, diffuse senile atrophy was also often seen in the organ of corti and the stria vascularis. A positive correlation between the degree of artheriosclerosis and the degree of sensorineural degeneration in the cochlea was not obtained in the present cases. Also, the correlation was not found to be consistent between the type of the audiometric curve and the localization of lesions in the sensory, the neural or the vascular elements in the cochlea. Our observations show that a certain type of audiometric curve does not necessarily indicate a lesion in a specific cochlear element.
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ranking = 1
keywords = spiral
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2/4. Multicentre evaluation of the temporal bones obtained from a patient with suspected Meniere's disease.

    A multicentre study of the inner ears of an 88-year-old patient with vertiginous spells and severe hearing loss in the left ear was performed, employing regular and block surface preparations, light and electron microscopy with qualitative and quantitative evaluation of the cochlear and vestibular nerves. There was severe hydrops of the left cochlea and saccule. Reissner's membrane extended into the vestibule and herniated into the perilymphatic space of the non-ampullated end of the horizontal canal. Furthermore, the short canal connecting the posterior ampulla with the utricle had a small, exceedingly thin balloon-like expansion. Only slight hydrops limited to the cochlea was found in the right ear. Sensorineural degeneration was much more pronounced in the left cochlea than in the right. The number of cochlear and vestibular nerve fibres was greatly reduced in the left ear where more fibres with degenerative changes were present. In both specimens the number of myelinated nerve fibres in osseous spiral lamina was smaller than that in the cochlear nerve in the internal auditory canal. Changes occurred in the endolymphatic sacs but were considered non-specific. In this case severe, apparently progressive hydrops and sensorineural degeneration, characteristic of Meniere's disease, were associated with atypical onset of clinical symptoms at a late age.
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ranking = 6848.3413542865
keywords = spiral lamina, spiral, lamina
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3/4. Application of electron microscopy to human otopathology. Ultrastructural findings in neural presbycusis, Meniere's disease and Usher's syndrome.

    Electron microscopy of well-preserved postmortem specimens of the inner ear of the human can provide significant details concerning human otopathology not discernible by light microscopy. As examples, ultrastructural findings in neural presbycusis, Meniere's disease and Usher's syndrome are presented. In all three pathologies there is evidence of neuronal degeneration, particularly within the dendritic arborization of the spiral ganglion, which is not observable by light microscopy.
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ranking = 1
keywords = spiral
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4/4. Electron microscopic findings in presbycusic degeneration of the basal turn of the human cochlea.

    Three human temporal bones with presbycusis affecting the basal turn of the cochlea were studied by light and electron microscopy. Conditions in two ears examined by light microscopy were typical of primary neural degeneration, with a descending audiometric pattern, loss of cochlear neurons in the basal turn, and preservation of the organ of corti. Ultrastructural analysis revealed normal hair cells and marked degenerative changes of the remaining neural fibers, expecially in the basal turn. These changes included a decrease in the number of synapses at the base of hair cells, accumulation of cellular debris in the spiral bundles, abnormalities of the dendritic fibers and their sheaths in the osseous spiral lamina, and degenerative changes in the spiral ganglion cells and axons. These changes were interpreted as an intermediate stage of degeneration prior to total loss of nerve fibers and ganglion cells as visualized by light microscopy. In the third ear the changes observed were typical of primary degeneration of hair and supporting cells in the basal turn with secondary neural degeneration. Additional observations at an ultrastructural level included maintenance of the tight junctions of the scala media despite loss of both hair and supporting cells, suggesting a capacity for cellular "healing" in the inner ear. Degenerative changes were found in the remaining neural fibers in the osseous spiral lamina. In addition, there was marked thickening of the basilar membrane in the basal turn, which consisted of an increased number of fibrils and an accumulation of amorphous osmiophilic material in the basilar membrane. This finding supports the concept that mechanical alterations may occur in presbycusis of the basal turn.
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ranking = 13698.682708573
keywords = spiral lamina, spiral, lamina
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