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Ishii M, Tanaka H, Asai R, Kanai Y, Kato Y, Ito Y, Mochizuki F, Yoneyama M, Ishiyama G, Ishiyama A. New non-contrast MRI of endolymphatic hydrops in Ménière's disease considering inversion time. Laryngoscope Investig Otolaryngol 2024; 9:e1314. [PMID: 39130211 PMCID: PMC11316216 DOI: 10.1002/lio2.1314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/10/2024] [Accepted: 07/20/2024] [Indexed: 08/13/2024] Open
Abstract
Objectives Three-tesla MRI with gadolinium-based contrast agents is important in diagnosing Ménière's disease. However, contrast agents cannot be used in some patients. By using the compositional difference between the inner ear endolymph and perilymph, we performed basic and clinical research focused on potassium ions and protein to find the optimal parameters for visualizing endolymphatic hydrops on MRI without contrast. We then examined the relationship between severity stage and visualization rate of endolymphatic hydrops. Methods In phantom experiments simulating the endolymph and perilymph, we explored MRI parameters that could be used to separate endolymph from perilymph by gradually changing the inversion time. We then used these parameters to perform both new non-contrast MRI and contrast MRI on the same day in Ménière's disease patients, and we compared the visualization rates of endolymphatic hydrops under the two modalities. Fifty patients were selected from 478 patients with Ménière's disease of different severity stages; 12 patients had asthma and allergy to contrast agents. Results The higher the disease stage, the higher the endolymphatic hydrops visualization rate. The new non-contrast MRI gave significantly higher (p < .01) visualization rates of endolymphatic hydrops on the affected side in patients at Stage 3 or above than in Stages 1 and 2 combined. Conclusion New non-contrast MRI with parameters focusing on the endolymph-perilymph difference in the density of protons surrounding the potassium ions and protein can produce images consistent with endolymphatic hydrops. We believe that this groundbreaking method will be useful for diagnosing Ménière's disease in patients. Evidence Level Clinical studies are at evidence level 3 in non-randomized controlled trials.
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Affiliation(s)
- Masanori Ishii
- Department of OtorhinolaryngologyJapan Community Healthcare Organization (JCHO) Tokyo Shinjuku Medical CenterTokyoJapan
- Department of NeurotologyAdvanced Imaging Center (AIC) Yaesu ClinicTokyoJapan
- Department of OtorhinolaryngologyThe Jikei University School of MedicineTokyoJapan
| | - Hiroshi Tanaka
- Department of RadiologyOchanomizu Surugadai ClinicTokyoJapan
| | - Ryuichi Asai
- Department of RadiologyAdvanced Imaging Center (AIC) Yaesu ClinicTokyoJapan
| | - Yasuhisa Kanai
- Department of RadiologyOchanomizu Surugadai ClinicTokyoJapan
| | - Yujin Kato
- Department of OtorhinolaryngologyThe Jikei University School of MedicineTokyoJapan
| | - Yusuke Ito
- Department of OtorhinolaryngologyThe Jikei University School of MedicineTokyoJapan
| | - Fumihiro Mochizuki
- Department of OtolaryngologyUniversity of Miami Miller School of MedicineMiamiFloridaUSA
| | | | - Gail Ishiyama
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - Akira Ishiyama
- Department of Head & Neck SurgeryDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
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Mohseni-Dargah M, Falahati Z, Pastras C, Khajeh K, Mukherjee P, Razmjou A, Stefani S, Asadnia M. Meniere's disease: Pathogenesis, treatments, and emerging approaches for an idiopathic bioenvironmental disorder. ENVIRONMENTAL RESEARCH 2023; 238:116972. [PMID: 37648189 DOI: 10.1016/j.envres.2023.116972] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/10/2023] [Accepted: 08/22/2023] [Indexed: 09/01/2023]
Abstract
Meniere's disease (MD) is a severe inner ear condition known by debilitating symptoms, including spontaneous vertigo, fluctuating and progressive hearing loss, tinnitus, and aural fullness or pressure within the affected ear. Prosper Meniere first described the origins of MD in the 1860s, but its underlying mechanisms remain largely elusive today. Nevertheless, researchers have identified a key histopathological feature called Endolymphatic Hydrops (ELH), which refers to the excessive buildup of endolymph fluid in the membranous labyrinth of the inner ear. The exact root of ELH is not fully understood. Still, it is believed to involve several biological and bioenvironmental etiological factors such as genetics, autoimmunity, infection, trauma, allergy, and new theories, such as saccular otoconia blocking the endolymphatic duct and sac. Regarding treatment, there are no reliable and definitive cures for MD. Most therapies focus on managing symptoms and improving the overall quality of patients' life. To make significant advancements in addressing MD, it is crucial to gain a fundamental understanding of the disease process, laying the groundwork for more effective therapeutic approaches. This paper provides a comprehensive review of the pathophysiology of MD with a focus on old and recent theories. Current treatment strategies and future translational approaches (with low-level evidence but promising results) related to MD are also discussed, including patents, drug delivery, and nanotechnology, that may provide future benefits to patients suffering from MD.
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Affiliation(s)
- Masoud Mohseni-Dargah
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia; Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Zahra Falahati
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran
| | - Christopher Pastras
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia; The Meniere's Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Khosro Khajeh
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Payal Mukherjee
- RPA Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Amir Razmjou
- Centre for Technology in Water and Wastewater, University of Technology Sydney, New South Wales 2007, Australia
| | - Sebastian Stefani
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia
| | - Mohsen Asadnia
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
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Kashizadeh A, Pastras C, Rabiee N, Mohseni-Dargah M, Mukherjee P, Asadnia M. Potential nanotechnology-based diagnostic and therapeutic approaches for Meniere's disease. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2022; 46:102599. [PMID: 36064032 DOI: 10.1016/j.nano.2022.102599] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Meniere's disease (MD) is a progressive inner ear disorder involving recurrent and prolonged episodes or attacks of vertigo with associated symptoms, resulting in a significantly reduced quality of life for sufferers. In most cases, MD starts in one ear; however, in one-third of patients, the disorder progresses to the other ear. Unfortunately, the etiology of the disease is unknown, making the development of effective treatments difficult. Nanomaterials, including nanoparticles (NPs) and nanocarriers, offer an array of novel diagnostic and therapeutic applications related to MD. NPs have specific features such as biocompatibility, biochemical stability, targetability, and enhanced visualization using imaging tools. This paper provides a comprehensive and critical review of recent advancements in nanotechnology-based diagnostic and therapeutic approaches for MD. Furthermore, the crucial challenges adversely affecting the use of nanoparticles to treat middle ear disorders are investigated. Finally, this paper provides recommendations and future directions for improving the performances of nanomaterials on theragnostic applications of MD.
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Affiliation(s)
- Afsaneh Kashizadeh
- School of Electrical and Computer Engineering, Shahid Beheshti University, Tehran 1983969411, Iran
| | - Christopher Pastras
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia; The Menière's Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Navid Rabiee
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia
| | - Masoud Mohseni-Dargah
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia; Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Payal Mukherjee
- RPA Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Mohsen Asadnia
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia.
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Grosser D, Willenborg K, Dellani P, Avallone E, Götz F, Böthig D, Warnecke A, Lanfermann H, Lenarz T, Giesemann A. Vestibular Aqueduct Size Correlates With the Degree of Cochlear Hydrops in Patients With and Without Menière's Disease. Otol Neurotol 2021; 42:e1532-e1536. [PMID: 34766949 DOI: 10.1097/mao.0000000000003300] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To correlate the CT imaging findings of the visibility and size of the vestibular aqueduct (VA) with the degree of the cochlear hydrops determined in MRI late imaging of the hydrops. Study Design: Retrospective study. Setting: Tertiary referral center. Patients: A total of 127 patients (62 women, 65 men, average age 55.6 yrs): 86 of these were diagnosed with Menière's disease (American Academy of Otolaryngology-Head and Neck Surgery [AAO-HNS] criteria; 67 unilateral, 19 bilateral). INTERVENTIONS Temporal bone CT and hydrops MRI were performed in all patients. MAIN OUTCOME MEASURES Visibility/width of the VA in temporal bone CT and grade of cochlear hydrops evaluated by MRI. RESULTS The width of the VA is significantly smaller in patients diagnosed with Menière's disease (30% non-visible VA), compared with the patients who did not fulfill the diagnostic criteria of Menière's disease (12% non-visible VA) (double sided Spearman correlation, p < 0.001). In all ears of patients diagnosed with Menière's disease the width of the VA was significantly correlated with the degree of the cochlear hydrops (in cases of non-visible VA 65% [34/52] ears presented with hydrops grade 3 or 4; 13% [7/52] ears presented with hydrops grade 1 or 2 and 21% [11/52] ears showed no hydrops) (Spearman correlation p = 0.001/p < 0.01). This is also true for all ears that can be summarized as hydrophic ear disease (symptomatic ears that present with a hydrops in MRI). CONCLUSIONS The results of our study could confirm the importance of the VA in the pathogenesis of the endolymphatic hydrops in vivo.
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Affiliation(s)
- Desiree Grosser
- Institute for Diagnostic and Interventional Neuroradiology
- Institute for Otorhinolaryngology
| | | | - Paulo Dellani
- Institute for Diagnostic and Interventional Neuroradiology
| | - Emilio Avallone
- Diagnostic and Interventional Radiology, Klinikum Region Hannover
| | - Friedrich Götz
- Institute for Diagnostic and Interventional Neuroradiology
| | - Dietmar Böthig
- Clinic for Pediatric Cardiology and Intensive Care, Hannover Medical school, Hannover, Germany
| | | | | | - Thomas Lenarz
- Diagnostic and Interventional Radiology, Klinikum Region Hannover
| | - Anja Giesemann
- Institute for Diagnostic and Interventional Neuroradiology
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Hornibrook J, Mudry A, Curthoys I, Smith CM. Ductus Reuniens and Its Possible Role in Menière's Disease. Otol Neurotol 2021; 42:1585-1593. [PMID: 34766952 DOI: 10.1097/mao.0000000000003352] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE After 160 years the true underlying cause of Meniere's disease remains enigmatic. The aim of our study is to discuss the possible implication of an obstruction of the ductus reuniens as a cause in Menière's disease. METHODOLOGY We first conducted an historical study of the description of the ductus reuniens. We then reviewed the literature regarding ductus reuniens obstruction in animal experiments, human post-mortem studies and living ear imaging. We completed its description by modern microCT imaging. Limited knowledge on the fate of dislodged saccular otoconia is summarized. The possible implications for Meniere's attacks are discussed. RESULTS Victor Hensen was the first to describe the ductus reuniens in 1863. He described its length and width and predicted that saccular otoconia might enter the ductus and the cochlea. On microCT the narrowest width of the human ductus reuniens was 0.14 mm. The literature reports cochlear endolymphatic hydrops occurring after animal experimental obstruction of the duct. Human postmortem studies have confirmed saccular otoconial clumps entering the ductus and the cochlea. A postmortem study has shown sites of endolymphatic obstruction, and imaging speculates on blockages in ears with Meniere's disease. Dislodged utricular otoconia can be in clumps of otolithic membranes. CONCLUSION Blockages of the ductus reuniens and at other endolymphatic system sites appear to be a feature in Meniere's disease ears. The blockages have been postulated to be saccular otoconia either causing or aggravating hydrops. This could be consistent with observed nystagmus reversals during attacks as the endolymphatic sac attempts to clear the hydrops and the otoconia.
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Affiliation(s)
- Jeremy Hornibrook
- Department of Otolaryngology - Head Neck Surgery, Christchurch Hospital, Christchurch, New Zealand
| | - Albert Mudry
- Department of Otolaryngology - Head and Neck Surgery, Stanford University, School of Medicine, Stanford, California, USA
| | - Ian Curthoys
- Vestibular Research Laboratory, School of Psychology, University of Sydney, New South Wales, Australia
| | - Christopher M Smith
- Department of Anthropology, The Graduate Center, City University of New York, New York, New York, USA
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
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Young AS, Nham B, Bradshaw AP, Calic Z, Pogson JM, Gibson WP, Halmagyi GM, Welgampola MS. Clinical, oculographic and vestibular test characteristics of Ménière's disease. J Neurol 2021; 269:1927-1944. [PMID: 34420063 DOI: 10.1007/s00415-021-10699-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/02/2021] [Accepted: 07/02/2021] [Indexed: 01/14/2023]
Abstract
Seventy Ménière's disease (MD) patients with spontaneous vertigo (100%), unilateral aural fullness (57.1%), tinnitus (78.6%), and subjective hearing loss (75.7%) self-recorded nystagmus during their episodes of vertigo using portable video oculography goggles. All demonstrated ictal spontaneous nystagmus, horizontal in 94.3% (n = 66) and vertical in 5.7% (n = 4), with a mean slow-phase velocity (SPV) of 42.8 ± 31.1°/s (range 5.3-160.1). Direction reversal of spontaneous horizontal nystagmus was captured in 58.6%, within the same episode in 34.3%, and over different days in 24.3%. In 18.6%, we observed ipsiversive then contraversive nystagmus, and in 12.9% contraversive to ipsiversive direction reversal. Ictal nystagmus SPV (42.8 ± 31.1°/s) was significantly faster than interictal (1.4 ± 3.1°/s, p < 0.001, CI 34.277-48.776). Compared to age-matched healthy controls, interictal video head impulse test gains in MD ears were significantly lower, cumulative and first saccade (S1) amplitudes were significantly larger, and S1 peak velocities were significantly faster (p = 0.038/0.019/0.008/ < 0.001, CI 0.002-0.071/0.130-1.444/0.138-0.909/14.614-41.506). Audiometry showed asymmetrically increased thresholds in 100% of MD ears (n = 70). Significant caloric, air-conducted (AC) cervical vestibular-evoked myogenic potential (VEMP), and AC ocular VEMP asymmetries were found in 61.4, 37.9, and 44.4% of patients (MD ear reduced). Transtympanic electrocochleography tested in 36 ears (23 patients) showed 81.8% of MD ears had a positive result for hydrops (either a summating potential at 1/2 kHz < - 6 µV, or an SP/AP ratio > 40%). Using ictal nystagmus findings of SPV > 12°/s, and a caloric canal paresis > 25%, we correctly separated a diagnosis MD from Vestibular Migraine with a sensitivity and specificity of 95.7% and 85.1% (CI 0.89-0.97).
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Affiliation(s)
- Allison S Young
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia.,Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Benjamin Nham
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia.,Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Andrew P Bradshaw
- Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Zeljka Calic
- Department of Neurophysiology, Liverpool Hospital, Liverpool, NSW, Australia
| | - Jacob M Pogson
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | | | - G Michael Halmagyi
- Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Miriam S Welgampola
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia. .,Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
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3D-reconstructions of Bast's Valve and Membranous Labyrinth: Insights for Vestibular Implantation and Meniere's Disease. Otol Neurotol 2021; 42:e1652-e1660. [PMID: 34172664 DOI: 10.1097/mao.0000000000003239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS/BACKGROUND Bast's valve is a poorly understood inner ear structure located at the junction between pars superior and inferior in the membranous labyrinth. Anatomically precise three-dimensional reconstructions (3D-reconstructions) of Bast's valve can help illuminate the morphology of the valve, and point toward its role in normal physiology and pathological states such as endolymphatic hydrops. This is of particular relevance to the development of a vestibular implant, a device intended to rehabilitate deficits in the vestibular system. METHODS Six postmortem human temporal bones from healthy donors were scanned using a micro-computed tomography (microCT) scanner. The microCT data allowed 3D-reconstructions of the membranous labyrinth, with a particular focus on Bast's valve, vestibule, and cochlear duct. RESULTS The microCT images of Bast's valve showed a rigid lip containing a core of soft tissue, opposing the thin membranous wall of the utricle. The maximum recorded length and width of the rigid lip were 440.4 μm and 88 μm, respectively. The 3D-reconstructions illustrated the slit-like opening of Bast's valve into the utricle, the twisting course of the basal turn of the cochlear duct, and the spatial orientation of utricle and saccule with respect to the stapes footplate. CONCLUSIONS The present study provided a novel anatomical perspective on the microscopic structure of Bast's valve. The interplay between endolymphatic hydrops and Bast's valve is an ongoing area of research, but defining this anatomy in 3D will play a key role in furthering our understanding of the disease process. Implications for vestibular implantation are explored through the various 3D-reconstructions.
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Li H, Rajan GP, Shaw J, Rohani SA, Ladak HM, Agrawal S, Rask-Andersen H. A Synchrotron and Micro-CT Study of the Human Endolymphatic Duct System: Is Meniere's Disease Caused by an Acute Endolymph Backflow? Front Surg 2021; 8:662530. [PMID: 34136526 PMCID: PMC8200827 DOI: 10.3389/fsurg.2021.662530] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/19/2021] [Indexed: 11/13/2022] Open
Abstract
Background: The etiology of Meniere's disease (MD) and endolymphatic hydrops believed to underlie its symptoms remain unknown. One reason may be the exceptional complexity of the human inner ear, its vulnerability, and surrounding hard bone. The vestibular organ contains an endolymphatic duct system (EDS) bridging the different fluid reservoirs. It may be essential for monitoring hydraulic equilibrium, and a dysregulation may result in distension of the fluid spaces or endolymphatic hydrops. Material and Methods: We studied the EDS using high-resolution synchrotron phase contrast non-invasive imaging (SR-PCI), and micro-computed tomography (micro-CT). Ten fresh human temporal bones underwent SR-PCI. One bone underwent micro-CT after fixation and staining with Lugol's iodine solution (I2KI) to increase tissue resolution. Data were processed using volume-rendering software to create 3D reconstructions allowing orthogonal sectioning, cropping, and tissue segmentation. Results: Combined imaging techniques with segmentation and tissue modeling demonstrated the 3D anatomy of the human saccule, utricle, endolymphatic duct, and sac together with connecting pathways. The utricular duct (UD) and utriculo-endolymphatic valve (UEV or Bast's valve) were demonstrated three-dimensionally for the first time. The reunion duct was displayed with micro-CT. It may serve as a safety valve to maintain cochlear endolymph homeostasis under certain conditions. Discussion: The thin reunion duct seems to play a minor role in the exchange of endolymph between the cochlea and vestibule under normal conditions. The saccule wall appears highly flexible, which may explain occult hydrops occasionally preceding symptoms in MD on magnetic resonance imaging (MRI). The design of the UEV and connecting ducts suggests that there is a reciprocal exchange of fluid among the utricle, semicircular canals, and the EDS. Based on the anatomic framework and previous experimental data, we speculate that precipitous vestibular symptoms in MD arise from a sudden increase in endolymph pressure caused by an uncontrolled endolymphatic sac secretion. A rapid rise in UD pressure, mediated along the fairly wide UEV, may underlie the acute vertigo attack, refuting the rupture/K+-intoxication theory.
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Affiliation(s)
- Hao Li
- Department of Surgical Sciences, Section of Otolaryngology and Head and Neck Surgery, Uppsala University Hospital, Uppsala, Sweden
| | - Gunesh P. Rajan
- Department of Otolaryngology, Head and Neck Surgery, Luzerner Kantonsspital, Lucerne, Switzerland
- Department of Otolaryngology, Head and Neck Surgery Division of Surgery, Medical School, University of Western Australia, Perth, WA, Australia
| | - Jeremy Shaw
- Centre for Microscopy, Characterisation and Analysis, Perth, WA, Australia
| | - Seyed Alireza Rohani
- Department of Otolaryngology-Head and Neck Surgery, Western University, London, ON, Canada
| | - Hanif M. Ladak
- Department of Medical Biophysics and Department of Electrical and Computer Engineering, Western University, London, ON, Canada
| | - Sumit Agrawal
- Department of Otolaryngology-Head and Neck Surgery, Western University, London, ON, Canada
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Section of Otolaryngology and Head and Neck Surgery, Uppsala University Hospital, Uppsala, Sweden
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Pastras CJ, Stefani SP, Curthoys IS, Camp AJ, Brown DJ. Utricular Sensitivity during Hydrodynamic Displacements of the Macula. J Assoc Res Otolaryngol 2020; 21:409-423. [PMID: 32783163 DOI: 10.1007/s10162-020-00769-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/31/2020] [Indexed: 01/02/2023] Open
Abstract
To explore the effects of cochlear hair cell displacement, researchers have previously monitored functional and mechanical responses during low-frequency (LF) acoustic stimulation of the cochlea. The induced changes are believed to result from modulation of the conductance of mechano-electrical transduction (MET) channels on cochlear hair cells, along with receptor potential modulation. It is less clear how, or if, vestibular hair cell displacement affects vestibular function. Here, we have used LF (<20 Hz) hydrodynamic modulation of the utricular macula position, whilst recording functional and mechanical responses, to investigate the effects of utricular macula displacement. Measured responses included the Utricular Microphonic (UM), the vestibular short-latency evoked potential (VsEP), and laser Doppler vibrometry recordings of macular position. Over 1 cycle of the LF bias, the UM amplitude and waveform were cyclically modulated, with Boltzmann analysis suggesting a cyclic modulation of the vestibular MET gating. The VsEP amplitude was cyclically modulated throughout the LF bias, demonstrating a relative increase (~20-50 %; re baseline) and decrease (~10-20 %; re baseline), which is believed to be related to the MET conductance and vestibular hair cell sensitivity. The relationship between macular displacement and changes in UM and VsEP responses was consistent within and across animals. These results suggest that the sensory structures underlying the VsEP, often thought to be a cranial jerk-sensitive response, are at least partially sensitive to LF (and possibly static) pressures or motion. Furthermore, these results highlight the possibility that some of the vestibular dysfunction related to endolymphatic hydrops may be due to altered vestibular transduction following mechanical (or morphological) changes in the labyrinth.
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Affiliation(s)
- Christopher John Pastras
- The Meniere's Laboratory, School of Medical Sciences, The University of Sydney, Medical Foundation Building, 92-94 Parramatta Road, Camperdown, Sydney, New South Wales, 2050, Australia.
| | - Sebastian Paolo Stefani
- The Meniere's Laboratory, School of Medical Sciences, The University of Sydney, Medical Foundation Building, 92-94 Parramatta Road, Camperdown, Sydney, New South Wales, 2050, Australia
| | - Ian S Curthoys
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, New South Wales, 2050, Australia
| | - Aaron James Camp
- The Meniere's Laboratory, School of Medical Sciences, The University of Sydney, Medical Foundation Building, 92-94 Parramatta Road, Camperdown, Sydney, New South Wales, 2050, Australia
| | - Daniel John Brown
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, Western Australia, 6102, Australia
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Brown DJ, Sokolic L, Fung A, Pastras CJ. Response of the inner ear to lipopolysaccharide introduced directly into scala media. Hear Res 2018; 370:105-112. [PMID: 30366193 DOI: 10.1016/j.heares.2018.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/03/2018] [Accepted: 10/14/2018] [Indexed: 12/18/2022]
Abstract
In an attempt to develop an animal model of immune mediated Meniere's disease, we have injected lipopolysaccharide (LPS) directly into scala media of guinea pigs and monitored functional and morphological changes over a period of 6 weeks. Depending on the concentration of LPS, changes ranged from moderate-to-severe hearing loss and endolymphatic hydrops with minimal cellular infiltrate or fibrosis, to dense cellular infiltration that filled the scalae. Interestingly, higher concentrations of LPS not only induced severe cellular infiltration, hydrops, and hearing loss, but also a substantial enlargement of the endolymphatic duct and sac. Moreover, LPS injections into perilymph failed to induce hydrops, yet still resulted in cellular infiltration and fibrosis in the cochlea. This suggests that chronic hydrops resulting from an immune challenge of the cochlea may not be due to blockage of the endolymphatic duct and sac, restricting fluid absorption. Furthermore, injecting antigen into endolymph may produce chronic immune-mediated hydrops, and provide a more promising animal model of Meniere's, although animals did not display signs of vestibular dysfunction, and the hearing loss was relatively severe.
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Affiliation(s)
| | - Ljiljana Sokolic
- The University of Sydney, Meniere's Research Laboratory, Australia
| | - Albert Fung
- The University of Sydney, Meniere's Research Laboratory, Australia
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Saccular otoconia as a cause of Ménière's disease: hypothesis based on two theories. The Journal of Laryngology & Otology 2018; 132:771-774. [PMID: 30149814 DOI: 10.1017/s0022215118001366] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The cause of Ménière's disease remains enigmatic after 156 years. Schuknecht's rupture and potassium intoxication theory of attacks was based on histological studies. OBJECTIVES This paper aimed to: present the most contemporary evidence indicating that ruptures do not usually occur, and discuss the possibility that detached saccular otoconia are the main cause of Ménière's disease; and to establish an unequivocal definition of the age of Ménière's disease onset. METHOD The paper reviews the electrophysiological basis of the Gibson-Arenberg drainage theory used to explain vertigo attacks. The current, limited knowledge of the likely fate of detached saccular otoconia is discussed. RESULTS Electrophysiological studies during attacks do not support endolymph ruptures, but rather endolymph flowing in one direction and then in the opposite direction. Age of onset for Ménière's disease parallels that for benign paroxysmal positional vertigo. CONCLUSION The similarity of age of onset spectrum for Ménière's disease and benign paroxysmal positional vertigo raises the possibility that the two conditions have the same fundamental cause.
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Brown DJ, Pastras CJ, Curthoys IS. Electrophysiological Measurements of Peripheral Vestibular Function-A Review of Electrovestibulography. Front Syst Neurosci 2017; 11:34. [PMID: 28620284 PMCID: PMC5450778 DOI: 10.3389/fnsys.2017.00034] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/05/2017] [Indexed: 12/19/2022] Open
Abstract
Electrocochleography (EcochG), incorporating the Cochlear Microphonic (CM), the Summating Potential (SP), and the cochlear Compound Action Potential (CAP), has been used to study cochlear function in humans and experimental animals since the 1930s, providing a simple objective tool to assess both hair cell (HC) and nerve sensitivity. The vestibular equivalent of ECochG, termed here Electrovestibulography (EVestG), incorporates responses of the vestibular HCs and nerve. Few research groups have utilized EVestG to study vestibular function. Arguably, this is because stimulating the cochlea in isolation with sound is a trivial matter, whereas stimulating the vestibular system in isolation requires significantly more technical effort. That is, the vestibular system is sensitive to both high-level sound and bone-conducted vibrations, but so is the cochlea, and gross electrical responses of the inner ear to such stimuli can be difficult to interpret. Fortunately, several simple techniques can be employed to isolate vestibular electrical responses. Here, we review the literature underpinning gross vestibular nerve and HC responses, and we discuss the nomenclature used in this field. We also discuss techniques for recording EVestG in experimental animals and humans and highlight how EVestG is furthering our understanding of the vestibular system.
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Affiliation(s)
- Daniel J Brown
- Neurotology Laboratory, Sydney Medical School, The University of SydneySydney, NSW, Australia
| | - Christopher J Pastras
- Neurotology Laboratory, Sydney Medical School, The University of SydneySydney, NSW, Australia
| | - Ian S Curthoys
- Department of Psychology, The University of SydneySydney, NSW, Australia
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Brown DJ, Pastras CJ, Curthoys IS, Southwell CS, Van Roon L. Endolymph movement visualized with light sheet fluorescence microscopy in an acute hydrops model. Hear Res 2016; 339:112-24. [PMID: 27377233 DOI: 10.1016/j.heares.2016.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/30/2016] [Accepted: 06/13/2016] [Indexed: 10/21/2022]
Abstract
There are a variety of techniques available to investigate endolymph dynamics, primarily seeking to understand the cause of endolymphatic hydrops. Here we have taken the novel approach of injecting, via a glass micropipette, fluorescein isothiocyanate-dextran (FITC-dex) and artificial endolymph into scala media of anaesthetized guinea pigs, with subsequent imaging of the inner ear using Light Sheet Fluorescence Microscopy (LSFM) as a means to obtain highly resolved 3D visualization of fluid movements. Our results demonstrate endolymph movement into the utricle, semicircular canals and endolymphatic duct and sac when more than 2.5 μl of fluid had been injected into scala media, with no apparent movement of fluid into the perilymphatic compartments. There was no movement of endolymph into these compartments when less than 2.5 μl was injected. The remarkable uptake of the FITC-dex into the endolymphatic duct, including an absorption into the periductal channels surrounding the endolymphatic duct, highlights the functional role this structure plays in endolymph volume regulation.
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Affiliation(s)
- Daniel J Brown
- Sydney Medical School, The University of Sydney, Sydney, NSW, 2050, Australia.
| | | | - Ian S Curthoys
- Vestibular Research Laboratory, The University of Sydney, School of Psychology, Sydney, NSW, 2050, Australia
| | | | - Lieke Van Roon
- University of Utrecht, Faculty Nature and Technique, Inst. for Life Sciences and Chemistry, Utrecht, 3508 AD, The Netherlands
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Dastgheib ZA, Lithgow B, Blakely B, Moussavi Z. Application of Vestibular Spontaneous Response as a Diagnostic Aid for Meniere's Disease. Ann Biomed Eng 2015; 44:1672-84. [PMID: 26334355 DOI: 10.1007/s10439-015-1441-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 08/26/2015] [Indexed: 01/14/2023]
Abstract
In this paper, we report on a new method for assisting in Meniere's disease diagnosis. An accurate diagnosis of Meniere's is challenging, and requires an expert opinion after observing several clinical assessments and tests over a period of time. Our proposed method is based on the analysis of the spontaneous and driven ear evoked responses recorded using Electrovestibulography (EVestG). We used the EVestG signals of 35 individuals suspected of Meniere's and 26 age-matched healthy controls, out of which data of 14 patients with Meniere's and 16 healthy controls were used for developing the diagnostic algorithm (training set) and the rest for testing. While recording and analyzing the test dataset, the researchers were only aware the patients suffered some dizziness, and were kept blind to the exact diagnoses till the end of study. EVestG field potentials (FPs) and their firing pattern, in response to several whole body tilt stimuli from both left and right ears were extracted. We investigated several features of the extracted FPs in response to each of side, back/forward, rotation, up/down, supine rotation, and supine up/down tilt stimulations, and selected the top five features showing the most significant differences between of the groups of the training set for every tilt. An ad-hoc average voting classifier was designed based on building five single-feature classifiers (using Linear Discriminant analysis) and taking the average of the single-feature classifiers' votes. The results showed the side tilt data were best for the purpose of Meniere's diagnosis; it resulted in 78% and 90% sensitivity and specificity for test dataset, respectively. The second best accuracy was achieved using back/forward tilt. The results and their implications are discussed. Overall, the EVestG side tilt results encourage the use of vestibular response as a non-invasive, robust and quick screening for Meniere's and separating it from other types of dizziness.
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Affiliation(s)
- Z A Dastgheib
- Biomedical Engineering, Department of Electrical & Computer Engineering, University of Manitoba, Room E3-512 Eng. Bldg., 75A Chancellor's Circle, Winnipeg, MB, R3T 5V6, Canada
| | - B Lithgow
- Electrical & Computer Engineering and Biomedical Engineering Program, University of Manitoba, Winnipeg, Canada
- Monash-Alfred Psychiatry Research Centre, Alfred Hospital, Melbourne, Australia
- Riverview Health Centre, Room PE456, 1 Morley Avenue, Winnipeg, MB, R3L2P4, Canada
| | - B Blakely
- Department of Otolaryngology - Head and Neck Surgery, GB421 - 820 Sherbrook Street, Winnipeg, MB, R3A 1R9, Canada
| | - Z Moussavi
- Biomedical Engineering, Department of Electrical & Computer Engineering, Room E3-513 Eng. Bldg., 75A Chancellor's Circle, Winnipeg, MB, R3T 5V6, Canada.
- Riverview Health Center, Winnipeg, Canada.
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