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Paul F. Smith - One of the best experts on this subject based on the ideXlab platform.
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stratification of hippocampal electrophysiological activation evoked by selective electrical stimulation of different angular and linear acceleration sensors in the rat Peripheral Vestibular System
Hearing Research, 2021Co-Authors: Martin Hitier, Yiwen Zheng, Paul F. Smith, Go Sato, Yanfeng Zhang, Stephane BesnardAbstract:Abstract It has become well established that Vestibular information is important for hippocampal function and spatial memory. However, as yet, relatively little is known about how different kinds of Vestibular information are ‘represented’ in different parts of the hippocampus. This study used selective electrical stimulation of each of the 5 Vestibular sensors (the horizontal (HC), anterior (AC) and posterior (PC) semi-circular canals, and the utricle and saccule) in the rat and recorded local field potentials (LFPs) across the hippocampus, using a 16 electrode microarray. We found that stimulation of any Vestibular sensor in the left labyrinth evoked triphasic LFPs in both hippocampi, although it was clear that, in general, the amplitudes were greater for the right, contralateral side. This was particularly true for Phase 1 for the HC, AC, utricle and saccule, Phase 2 for the HC, PC, utricle and saccule, and Phase 3 for the AC, PC and saccule. Overall, our results suggest that Vestibular input to the hippocampus is bilateral, preferentially contralateral, but highly stratified in that stimulation of the same Vestibular sensor results in activation of different specific areas of the hippocampus, with different LFP amplitudes and latencies. This suggests the possibility that different regions of the hippocampus use different kinds of Vestibular information for different purposes and that there may be a high degree of redundancy in the representation of Vestibular input, perhaps ensuring that the hippocampus is more robust to the partial loss of Vestibular information.
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the effects of electrical stimulation of the Peripheral Vestibular System on neurochemical release in the rat striatum
PLOS ONE, 2018Co-Authors: Lucy Stiles, Yiwen Zheng, Paul F. SmithAbstract:For over a century, it has been speculated that the Vestibular System transmits information about self-motion to the striatum. There have been inconsistent reports of such a connection, and interest in the subject has been increased by the experimental use of galvanic Vestibular stimulation in the treatment of Parkinson's Disease patients. Nonetheless, there are few data available on the effects of Vestibular stimulation on neurochemical changes in the striatum. We used in vivo microdialysis to analyse changes in the extracellular levels of amino acids and monoamines in the rat striatum, following electrical Vestibular stimulation. Stimulation caused a significant decrease in serine and threonine, compared to the no-stimulation controls (P ≤ 0.005 and P ≤ 0.01, respectively). The ratio of DOPAC:dopamine, decreased on the ipsilateral side following stimulation (P ≤ 0.005). There was a significant treatment x side x intensity interaction for taurine levels (P ≤ 0.002), due to a decrease on the contralateral side in stimulated animals, which varied as a function of current. These results show that Peripheral Vestibular stimulation causes some neurochemical changes in the striatum and support the view that activaton of the Vestibular System exerts effects on the function of the striatum.
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Single neuron activity and c-Fos expression in the rat striatum following electrical stimulation of the Peripheral Vestibular System.
Physiological reports, 2018Co-Authors: Lucy Stiles, John N. J. Reynolds, Ruth M. A. Napper, Yiwen Zheng, Paul F. SmithAbstract:Connections between the Vestibular System and the basal ganglia have been postulated since the early 20th century. However, the results of electrophysiological studies investigating neuronal responses to electrical stimulation of the Vestibular System have been inconsistent. The aim of this study was to investigate the effects of electrical stimulation of the Vestibular labyrinth on single neuron activity and c-Fos expression in the rat striatum. We used electrical stimulation of the Vestibular labyrinth (various intensities delivered to the round window) to examine the electrophysiological response of striatal neurons and c-Fos expression. From 507 single neurons recorded (n = 20 rats), no Vestibular-responsive neuron was found at 1× and 2× the nystagmus threshold; however, 6 neurons were found at 3× the threshold. These neurons were found bilaterally, with a response latency of ~50 msec from the end of the stimulus. For the c-Fos study, the number of neurons expressing c-Fos was quantified using stereological methods. Stimulation at 2× the threshold for nystagmus (n = 5 rats) resulted in a significant decrease in the number of neurons expressing c-Fos in the bilateral striatum compared to both the sham control group (n = 5) and the lower stimulus intensity group (n = 5) (P ≤ 0.0001 for both). The results of this study demonstrate that: (1) some single striatal neurons respond to electrical Vestibular stimulation, however, these responses are circumscribed and infrequent; (2) electrical stimulation of the Vestibular labyrinth results in a decrease in the number of striatal neurons expressing c-Fos, in a current-dependent manner.
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effects of electrical stimulation of the rat Vestibular labyrinth on c fos expression in the hippocampus
Neuroscience Letters, 2018Co-Authors: Martin Hitier, Paul F. Smith, Go Sato, Yanfeng Zhang, Stephane BesnardAbstract:Abstract Several studies have demonstrated that electrical activation of the Peripheral Vestibular System can evoke field potential, multi-unit neuronal activity and acetylcholine release in the hippocampus (HPC). However, no study to date has employed the immediate early gene protein, c-Fos, to investigate the distribution of activation of cells in the HPC following electrical stimulation of the Vestibular System. We found that Vestibular stimulation increased the number of animals expressing c-Fos in the dorsal HPC compared to sham control rats (P ≤ 0.02), but not in the ventral HPC. c-Fos was also expressed in an increased number of animals in the dorsal dentate gyrus (DG) compared to sham control rats (P ≤ 0.0001), and to a lesser extent in the ventral DG (P ≤ 0.006). The results of this study show that activation of the Vestibular System results in a differential increase in the expression of c-Fos across different regions of the HPC.
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galvanic Vestibular stimulation impairs cell proliferation and neurogenesis in the rat hippocampus but not spatial memory
Hippocampus, 2014Co-Authors: Yiwen Zheng, Lucy Stiles, Go Sato, Lisa H Geddes, Cynthia L Darlington, Paul F. SmithAbstract:Galvanic Vestibular stimulation (GVS) is a method of activating the Peripheral Vestibular System using direct current that is widely employed in clinical neurological testing. Since movement is recognized to stimulate hippocampal neurogenesis and movement is impossible without activation of the Vestibular System, we speculated that activating the Vestibular System in rats while minimizing movement, by delivering GVS under anesthesia, would affect hippocampal cell proliferation and neurogenesis, and spatial memory. Compared with the sham control group, the number of cells incorporating the DNA replication marker, bromodeoxyuridine (BrdU), was significantly reduced in the bilateral hippocampi in both the cathode left-anode right and cathode right-anode left stimulation groups (P ≤ 0.0001). The majority of the BrdU+ve cells co-expressed Ki-67, a marker for the S phase of the cell cycle, suggesting that these BrdU+ve cells were still in the cell cycle; however, there was no significant difference in the degree of co-labeling between the two stimulation groups. Single labeling for doublecortin (DCX), a marker of immature neurons, showed that while there was no significant difference between the different groups in the number of DCX+ve cells in the right dentate gryus, in the left dentate gyrus there was a significant decrease in the cathode left-anode right group compared with the sham controls (P ≤ 0.03). Nonetheless, when animals were tested in place recognition, object exploration and Morris water maze tasks, there were no significant differences between the GVS groups and the sham controls. These results suggest that GVS can have striking effects on cell proliferation and possibly neurogenesis in the hippocampus, without affecting spatial memory. © 2014 Wiley Periodicals, Inc.
Sebahattin Cureoglu - One of the best experts on this subject based on the ideXlab platform.
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Peripheral Vestibular pathology in mondini dysplasia
Laryngoscope, 2017Co-Authors: Serdar Kaya, Fatima Kubra Kaya, Omer Hizli, Rafael Da Costa Monsanto, Michael M. Paparella, Sebahattin CureogluAbstract:In this study, our objective was to histopathologically analyze the Peripheral Vestibular System in patients with Mondini dysplasia.Comparative human temporal bone study.We assessed the sensory epithelium of the human Vestibular System with a focus on the number of type I and type II hair cells, as well as the total number of hair cells. We compared those numbers in our Mondini dysplasia group versus our control group.The loss of type I and type II hair cells in the cristae of the superior, lateral, and posterior semicircular canals, as well as in the saccular and utricular macula, was significantly higher in our Mondini dysplasia group than in our control group. The total number of hair cells significantly decreased in the cristae of the superior, lateral, and posterior semicircular canals, as well as in the saccular and utricular macula, in our Mondini dysplasia group.Loss of Vestibular hair cells can lead to Vestibular dysfunction in patients with Mondini dysplasia.NA Laryngoscope, 127:206-209, 2017.
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pathologic changes of the Peripheral Vestibular System secondary to chronic otitis media
Otolaryngology-Head and Neck Surgery, 2016Co-Authors: Rafael Da Costa Monsanto, Henrique Furlan Pauna, Geeyoun Kwon, Vladimir Tsuprun, Patricia A. Schachern, Michael M. Paparella, Mehmet Erdil, Sebahattin CureogluAbstract:ObjectiveTo evaluate the histopathologic changes of dark, transitional, and hair cells of the Vestibular System in human temporal bones from patients with chronic otitis media.Study DesignComparative human temporal bone study.SettingOtopathology laboratory.Subjects and MethodsTo compare the density of Vestibular dark, transitional, and hair cells in temporal bones with and without chronic otitis media, we used differential interference contrast microscopy.ResultsIn the chronic otitis media group (as compared with the age-matched control group), the density of type I and type II hair cells was significantly decreased in the lateral semicircular canal, saccule, and utricle (P < .05). The density of type I cells was also significantly decreased in the chronic otitis media group in the posterior semicircular canal (P = .005), but that of type II cells was not (P = .168). The mean number of dark cells was significantly decreased in the chronic otitis media group in the lateral semicircular canal (P = .014) and...
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histopathologic findings in Peripheral Vestibular System from patients with Systemic lupus erythematosus a human temporal bone study
Otology & Neurotology, 2015Co-Authors: Shin Kariya, Omer Hizli, Serdar Kaya, Michael M. Paparella, Kazunori Nishizaki, Pelin Hizli, Sebahattin CureogluAbstract:Hypothesis: We hypothesized that a pathologic condition exists in Vestibular hair cells in human temporal bones from patients with Systemic lupus erythematosus (SLE). Background: A significant association between sensorineural hearing loss and autoimmune disease has been reported. Patients with SLE also frequently have Vestibular symptoms whose pathophysiologic mechanism is unclear. Methods: We examined 15 temporal bone samples from 8 patients with SLE, along with 21 samples from 17 age-matched healthy control patients. The samples were serially sectioned in the horizontal plane and stained with hematoxylin and eosin. Using differential interference contrast microscopy, we counted the number of type I and type II hair cells in the saccular macula, the utricular macula, and the cristae of the three semicircular canals; then, we calculated the hair cell density (cells per 0.01 mm2). Results: The mean density of type I hair cells in our SLE group was significantly lower than in our control group in the saccular macula, in the utricular macula, and in the superior, lateral, and posterior semicircular canals. But in all five Vestibular sensory epithelia, the mean density of type II hair cells did not significantly differ between our two groups. In our SLE group, the mean density of Vestibular hair cells did not significantly correlate with the patient's age at death or with the duration of SLE. Conclusion: Type I hair cells in Peripheral Vestibular organs are affected in patients with SLE. Our findings could provide a pathologic basis for the difficulty with balance experienced by patients with SLE.
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Peripheral Vestibular System in down syndrome quantitative assessment of Vestibular histopathology
Otolaryngology-Head and Neck Surgery, 2011Co-Authors: Taro Inagaki, Sebahattin Cureoglu, Patricia A. Schachern, Norimasa Morita, Shigenobu Nomiya, Rie Nomiya, Michael M. PaparellaAbstract:Objective To evaluate the maturity of the Peripheral Vestibular System in Down syndrome by examining the number of Scarpa's ganglion cells and the density of Vestibular hair cells. Study design Case-control study using human temporal bones. Setting Tertiary academic center, otopathology laboratory. Subjects and methods Sixteen temporal bones from 8 patients with Down syndrome and 15 control temporal bones from 8 individuals with no history of otologic disease were selected. Hypoplasia of the lateral semicircular canal (LSC) and vestibule was investigated by measuring the dimensions of the structures. Scarpa's ganglion cells were counted under light microscopy. The Vestibular hair cells were counted in the LSC crista and the utricular and saccular maculae under differential interference contrast (Nomarski) microscopy and expressed as density. Results The patients with Down syndrome were divided into 2 groups: with and without LSC hypoplasia. The number of Scarpa's ganglion cells and the density of Vestibular hair cells were significantly smaller in both groups of patients with Down syndrome than in the control group. There was no significant difference in the number of Scarpa's ganglion cells or the density of Vestibular hair cells between the groups with and without LSC hypoplasia. Conclusion The Peripheral Vestibular System, including Scarpa's ganglion cells and Vestibular hair cells, is hypoplastic irrespective of the Vestibular malformation in Down syndrome.
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quantitative study of the Vestibular sensory epithelium in cochleosaccular dysplasia
Otology & Neurotology, 2005Co-Authors: Sebahattin Cureoglu, Patricia A. Schachern, Michael M. Paparella, Shin Kariya, Andre Luiz Lopes Sampaio, Takeshi Kusunoki, Mehmet Faruk Oktay, Kazunori NishizakiAbstract:Background: Cochleosaccular dysplasia is the most common pathologic finding seen in children with profound congenital sensorineural hearing loss. There has been no quantitative study on the Peripheral Vestibular System in cochleosaccular dysplasia. Objective: To investigate quantitatively the extent of pathologic changes of the Vestibular sensory epithelium in cochleosaccular dysplasia. Subjects and Methods: Thirteen temporal bones with congenital deafness from 10 individuals were selected for this study from the temporal bone collection of University of Minnesota that showed suitable pathologic findings for the histopathologic criteria of cochleosaccular dysplasia. Age-matched normal control temporal bones were also selected. The Vestibular hair cells including types I and II hair cells were counted separately in the saccular macula, utricular macula, and three cristae of the semicircular canals using Nomarski microscopy. Results: The hair cell densities of types I and II hair cells in the macula of the saccule in cochleosaccular dysplasia were significantly decreased compared with the data of normal subjects. Both types I and II hair cells in the utricular macula and the cristae of the three semicircular canals in cochleosaccular dysplasia were well preserved, and no significant difference was observed between findings of cochleosaccular dysplasia and normal controls in the utricle and the three semicircular canals. Conclusions: In cases with cochleosaccular dysplasia, the neurosensorial hair cells of the saccule were affected; however, the osseous labyrinth, the membranous utricle, and the semicircular canals were normal. Further studies should be performed to establish the pathogenesis of cochleosaccular dysplasia in humans.
Danielle R Trakimas - One of the best experts on this subject based on the ideXlab platform.
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Peripheral Vestibular organ degeneration after temporal bone fracture a human otopathology study
Laryngoscope, 2020Co-Authors: Renata M Knoll, Rory J Lubner, Reuven Ishai, Danielle R Trakimas, Jacob R BrodskyAbstract:OBJECTIVES/HYPOTHESIS Vestibular symptoms are a common sequela of temporal bone fractures (TBFs). The mechanisms of injury to the Peripheral Vestibular System following TBF, however, are not well described. Herein, we aimed to investigate the histopathology of the Peripheral Vestibular System in patients who sustained TBFs. STUDY DESIGN Retrospective human specimen analysis. METHODS Specimens from the National Temporal Bone Pathology Registry with (cases) and without (controls) TBFs were evaluated. Specimens were analyzed by light microscopy for Vestibular hair cell and/or dendritic degeneration, presence of endolymphatic hydrops, blockage of the endolymphatic duct, and number of Scarpa ganglion cells (ScGCs) in the superior and inferior Vestibular nerves. RESULTS Seven temporal bones (TBs) from five individuals with TBFs, and seven TBs from six age-matched individuals without a history of head injury met inclusion and exclusion criteria. All fractures involved the otic capsule. Severe degeneration of the cristae was identified in the semicircular canals in all TBF cases. The utricular and saccular maculae showed mild to severe degeneration in the TBF cases. Vestibular hydrops (n = 2 TBs) and blockage of the endolymphatic duct (n = 3 TBs) were also present in the TBF cases. There was a decrease of 52.6% in the mean total ScGC count in the TBF cases (n = 3 TBs) compared to age-matched controls (n = 7 TBs, P = .015). There was a mean loss of 53% of the ScGCs in the superior Vestibular nerve and a mean loss of 52.3% of the ScGCs in the inferior Vestibular nerve compared to age-matched controls (P = .033 and P = .021, respectively). CONCLUSIONS In a cohort of patients with TBFs, there were distinct Peripheral Vestibular changes including reduction of ScGCs. LEVEL OF EVIDENCE NA Laryngoscope, 130:752-760, 2020.
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Peripheral Vestibular System histopathologic changes following head injury without temporal bone fracture
Otolaryngology-Head and Neck Surgery, 2019Co-Authors: Renata M Knoll, Joseph B. Nadol, Reuven Ishai, Danielle R Trakimas, Jenny X ChenAbstract:ObjectiveVestibular 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 sy...
Michael M. Paparella - One of the best experts on this subject based on the ideXlab platform.
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Peripheral Vestibular pathology in mondini dysplasia
Laryngoscope, 2017Co-Authors: Serdar Kaya, Fatima Kubra Kaya, Omer Hizli, Rafael Da Costa Monsanto, Michael M. Paparella, Sebahattin CureogluAbstract:In this study, our objective was to histopathologically analyze the Peripheral Vestibular System in patients with Mondini dysplasia.Comparative human temporal bone study.We assessed the sensory epithelium of the human Vestibular System with a focus on the number of type I and type II hair cells, as well as the total number of hair cells. We compared those numbers in our Mondini dysplasia group versus our control group.The loss of type I and type II hair cells in the cristae of the superior, lateral, and posterior semicircular canals, as well as in the saccular and utricular macula, was significantly higher in our Mondini dysplasia group than in our control group. The total number of hair cells significantly decreased in the cristae of the superior, lateral, and posterior semicircular canals, as well as in the saccular and utricular macula, in our Mondini dysplasia group.Loss of Vestibular hair cells can lead to Vestibular dysfunction in patients with Mondini dysplasia.NA Laryngoscope, 127:206-209, 2017.
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pathologic changes of the Peripheral Vestibular System secondary to chronic otitis media
Otolaryngology-Head and Neck Surgery, 2016Co-Authors: Rafael Da Costa Monsanto, Henrique Furlan Pauna, Geeyoun Kwon, Vladimir Tsuprun, Patricia A. Schachern, Michael M. Paparella, Mehmet Erdil, Sebahattin CureogluAbstract:ObjectiveTo evaluate the histopathologic changes of dark, transitional, and hair cells of the Vestibular System in human temporal bones from patients with chronic otitis media.Study DesignComparative human temporal bone study.SettingOtopathology laboratory.Subjects and MethodsTo compare the density of Vestibular dark, transitional, and hair cells in temporal bones with and without chronic otitis media, we used differential interference contrast microscopy.ResultsIn the chronic otitis media group (as compared with the age-matched control group), the density of type I and type II hair cells was significantly decreased in the lateral semicircular canal, saccule, and utricle (P < .05). The density of type I cells was also significantly decreased in the chronic otitis media group in the posterior semicircular canal (P = .005), but that of type II cells was not (P = .168). The mean number of dark cells was significantly decreased in the chronic otitis media group in the lateral semicircular canal (P = .014) and...
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histopathologic findings in Peripheral Vestibular System from patients with Systemic lupus erythematosus a human temporal bone study
Otology & Neurotology, 2015Co-Authors: Shin Kariya, Omer Hizli, Serdar Kaya, Michael M. Paparella, Kazunori Nishizaki, Pelin Hizli, Sebahattin CureogluAbstract:Hypothesis: We hypothesized that a pathologic condition exists in Vestibular hair cells in human temporal bones from patients with Systemic lupus erythematosus (SLE). Background: A significant association between sensorineural hearing loss and autoimmune disease has been reported. Patients with SLE also frequently have Vestibular symptoms whose pathophysiologic mechanism is unclear. Methods: We examined 15 temporal bone samples from 8 patients with SLE, along with 21 samples from 17 age-matched healthy control patients. The samples were serially sectioned in the horizontal plane and stained with hematoxylin and eosin. Using differential interference contrast microscopy, we counted the number of type I and type II hair cells in the saccular macula, the utricular macula, and the cristae of the three semicircular canals; then, we calculated the hair cell density (cells per 0.01 mm2). Results: The mean density of type I hair cells in our SLE group was significantly lower than in our control group in the saccular macula, in the utricular macula, and in the superior, lateral, and posterior semicircular canals. But in all five Vestibular sensory epithelia, the mean density of type II hair cells did not significantly differ between our two groups. In our SLE group, the mean density of Vestibular hair cells did not significantly correlate with the patient's age at death or with the duration of SLE. Conclusion: Type I hair cells in Peripheral Vestibular organs are affected in patients with SLE. Our findings could provide a pathologic basis for the difficulty with balance experienced by patients with SLE.
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Peripheral Vestibular System in down syndrome quantitative assessment of Vestibular histopathology
Otolaryngology-Head and Neck Surgery, 2011Co-Authors: Taro Inagaki, Sebahattin Cureoglu, Patricia A. Schachern, Norimasa Morita, Shigenobu Nomiya, Rie Nomiya, Michael M. PaparellaAbstract:Objective To evaluate the maturity of the Peripheral Vestibular System in Down syndrome by examining the number of Scarpa's ganglion cells and the density of Vestibular hair cells. Study design Case-control study using human temporal bones. Setting Tertiary academic center, otopathology laboratory. Subjects and methods Sixteen temporal bones from 8 patients with Down syndrome and 15 control temporal bones from 8 individuals with no history of otologic disease were selected. Hypoplasia of the lateral semicircular canal (LSC) and vestibule was investigated by measuring the dimensions of the structures. Scarpa's ganglion cells were counted under light microscopy. The Vestibular hair cells were counted in the LSC crista and the utricular and saccular maculae under differential interference contrast (Nomarski) microscopy and expressed as density. Results The patients with Down syndrome were divided into 2 groups: with and without LSC hypoplasia. The number of Scarpa's ganglion cells and the density of Vestibular hair cells were significantly smaller in both groups of patients with Down syndrome than in the control group. There was no significant difference in the number of Scarpa's ganglion cells or the density of Vestibular hair cells between the groups with and without LSC hypoplasia. Conclusion The Peripheral Vestibular System, including Scarpa's ganglion cells and Vestibular hair cells, is hypoplastic irrespective of the Vestibular malformation in Down syndrome.
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quantitative study of the Vestibular sensory epithelium in cochleosaccular dysplasia
Otology & Neurotology, 2005Co-Authors: Sebahattin Cureoglu, Patricia A. Schachern, Michael M. Paparella, Shin Kariya, Andre Luiz Lopes Sampaio, Takeshi Kusunoki, Mehmet Faruk Oktay, Kazunori NishizakiAbstract:Background: Cochleosaccular dysplasia is the most common pathologic finding seen in children with profound congenital sensorineural hearing loss. There has been no quantitative study on the Peripheral Vestibular System in cochleosaccular dysplasia. Objective: To investigate quantitatively the extent of pathologic changes of the Vestibular sensory epithelium in cochleosaccular dysplasia. Subjects and Methods: Thirteen temporal bones with congenital deafness from 10 individuals were selected for this study from the temporal bone collection of University of Minnesota that showed suitable pathologic findings for the histopathologic criteria of cochleosaccular dysplasia. Age-matched normal control temporal bones were also selected. The Vestibular hair cells including types I and II hair cells were counted separately in the saccular macula, utricular macula, and three cristae of the semicircular canals using Nomarski microscopy. Results: The hair cell densities of types I and II hair cells in the macula of the saccule in cochleosaccular dysplasia were significantly decreased compared with the data of normal subjects. Both types I and II hair cells in the utricular macula and the cristae of the three semicircular canals in cochleosaccular dysplasia were well preserved, and no significant difference was observed between findings of cochleosaccular dysplasia and normal controls in the utricle and the three semicircular canals. Conclusions: In cases with cochleosaccular dysplasia, the neurosensorial hair cells of the saccule were affected; however, the osseous labyrinth, the membranous utricle, and the semicircular canals were normal. Further studies should be performed to establish the pathogenesis of cochleosaccular dysplasia in humans.
Renata M Knoll - One of the best experts on this subject based on the ideXlab platform.
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Peripheral Vestibular organ degeneration after temporal bone fracture a human otopathology study
Laryngoscope, 2020Co-Authors: Renata M Knoll, Rory J Lubner, Reuven Ishai, Danielle R Trakimas, Jacob R BrodskyAbstract:OBJECTIVES/HYPOTHESIS Vestibular symptoms are a common sequela of temporal bone fractures (TBFs). The mechanisms of injury to the Peripheral Vestibular System following TBF, however, are not well described. Herein, we aimed to investigate the histopathology of the Peripheral Vestibular System in patients who sustained TBFs. STUDY DESIGN Retrospective human specimen analysis. METHODS Specimens from the National Temporal Bone Pathology Registry with (cases) and without (controls) TBFs were evaluated. Specimens were analyzed by light microscopy for Vestibular hair cell and/or dendritic degeneration, presence of endolymphatic hydrops, blockage of the endolymphatic duct, and number of Scarpa ganglion cells (ScGCs) in the superior and inferior Vestibular nerves. RESULTS Seven temporal bones (TBs) from five individuals with TBFs, and seven TBs from six age-matched individuals without a history of head injury met inclusion and exclusion criteria. All fractures involved the otic capsule. Severe degeneration of the cristae was identified in the semicircular canals in all TBF cases. The utricular and saccular maculae showed mild to severe degeneration in the TBF cases. Vestibular hydrops (n = 2 TBs) and blockage of the endolymphatic duct (n = 3 TBs) were also present in the TBF cases. There was a decrease of 52.6% in the mean total ScGC count in the TBF cases (n = 3 TBs) compared to age-matched controls (n = 7 TBs, P = .015). There was a mean loss of 53% of the ScGCs in the superior Vestibular nerve and a mean loss of 52.3% of the ScGCs in the inferior Vestibular nerve compared to age-matched controls (P = .033 and P = .021, respectively). CONCLUSIONS In a cohort of patients with TBFs, there were distinct Peripheral Vestibular changes including reduction of ScGCs. LEVEL OF EVIDENCE NA Laryngoscope, 130:752-760, 2020.
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histopathological changes to the Peripheral Vestibular System following meningitic labyrinthitis
Laryngoscope investigative otolaryngology, 2020Co-Authors: Henrique Furlan Pauna, Renata M Knoll, Rory J Lubner, Jacob R Brodsky, Sharon L Cushing, Miguel Angelo Hyppolito, Joseph B. Nadol, Aaron K RemenschneiderAbstract:Objective: While 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. Methods: Temporal 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. Results: Fifteen 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). Conclusions: Otopathologic 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 Evidence: N/A.
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Peripheral Vestibular System histopathologic changes following head injury without temporal bone fracture
Otolaryngology-Head and Neck Surgery, 2019Co-Authors: Renata M Knoll, Joseph B. Nadol, Reuven Ishai, Danielle R Trakimas, Jenny X ChenAbstract:ObjectiveVestibular 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 sy...