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Affortit C, Coyat C, Saidia AR, Ceccato JC, Charif M, Sarzi E, Flamant F, Guyot R, Cazevieille C, Puel JL, Lenaers G, Wang J. The human OPA1 delTTAG mutation induces adult onset and progressive auditory neuropathy in mice. Cell Mol Life Sci 2024; 81:80. [PMID: 38334784 PMCID: PMC10858076 DOI: 10.1007/s00018-024-05115-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 01/05/2024] [Accepted: 01/05/2024] [Indexed: 02/10/2024]
Abstract
Dominant optic atrophy (DOA) is one of the most prevalent forms of hereditary optic neuropathies and is mainly caused by heterozygous variants in OPA1, encoding a mitochondrial dynamin-related large GTPase. The clinical spectrum of DOA has been extended to a wide variety of syndromic presentations, called DOAplus, including deafness as the main secondary symptom associated to vision impairment. To date, the pathophysiological mechanisms underlying the deafness in DOA remain unknown. To gain insights into the process leading to hearing impairment, we have analyzed the Opa1delTTAG mouse model that recapitulates the DOAplus syndrome through complementary approaches combining morpho-physiology, biochemistry, and cellular and molecular biology. We found that Opa1delTTAG mutation leads an adult-onset progressive auditory neuropathy in mice, as attested by the auditory brainstem response threshold shift over time. However, the mutant mice harbored larger otoacoustic emissions in comparison to wild-type littermates, whereas the endocochlear potential, which is a proxy for the functional state of the stria vascularis, was comparable between both genotypes. Ultrastructural examination of the mutant mice revealed a selective loss of sensory inner hair cells, together with a progressive degeneration of the axons and myelin sheaths of the afferent terminals of the spiral ganglion neurons, supporting an auditory neuropathy spectrum disorder (ANSD). Molecular assessment of cochlea demonstrated a reduction of Opa1 mRNA level by greater than 40%, supporting haploinsufficiency as the disease mechanism. In addition, we evidenced an early increase in Sirtuin 3 level and in Beclin1 activity, and subsequently an age-related mtDNA depletion, increased oxidative stress, mitophagy as well as an impaired autophagic flux. Together, these results support a novel role for OPA1 in the maintenance of inner hair cells and auditory neural structures, addressing new challenges for the exploration and treatment of OPA1-linked ANSD in patients.
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Affiliation(s)
- Corentin Affortit
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, UMR 1298, 80 Rue Augustin Fliche, 34295, Montpellier, France
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, Head and Neck Surgery, University of Iowa, Iowa City, IA, 52242, USA
| | - Carolanne Coyat
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, UMR 1298, 80 Rue Augustin Fliche, 34295, Montpellier, France
| | - Anissa Rym Saidia
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, UMR 1298, 80 Rue Augustin Fliche, 34295, Montpellier, France
| | - Jean-Charles Ceccato
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, UMR 1298, 80 Rue Augustin Fliche, 34295, Montpellier, France
| | - Majida Charif
- Genetics, and Immuno-Cell Therapy Team, Mohamed First University, 60000, Oujda, Morocco
| | - Emmanuelle Sarzi
- Institut NeuroMyoGène, Pathophysiology and Genetics of Neuron and Muscle (INMG-PGNM) UCBL-CNRS UMR5261, Inserm U1315, Université Claude Bernard, Lyon I, Faculty of Medicine and Pharmacy, Lyon, France
| | - Frédéric Flamant
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS Lyon, Lyon, France
| | - Romain Guyot
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS Lyon, Lyon, France
| | - Chantal Cazevieille
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, UMR 1298, 80 Rue Augustin Fliche, 34295, Montpellier, France
| | - Jean-Luc Puel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, UMR 1298, 80 Rue Augustin Fliche, 34295, Montpellier, France
| | - Guy Lenaers
- Université Angers, MitoLab Team, Unité MitoVasc, UMR CNRS 6015, INSERM U1083, SFR ICAT, Angers, France
- Service de Neurologie, CHU d'Angers, Angers, France
| | - Jing Wang
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, UMR 1298, 80 Rue Augustin Fliche, 34295, Montpellier, France.
- Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, Montpellier, France.
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Fiorini C, Degiorgi A, Cascavilla ML, Tropeano CV, La Morgia C, Battista M, Ormanbekova D, Palombo F, Carbonelli M, Bandello F, Carelli V, Maresca A, Barboni P, Baruffini E, Caporali L. Recessive MECR pathogenic variants cause an LHON-like optic neuropathy. J Med Genet 2023; 61:93-101. [PMID: 37734847 PMCID: PMC10804020 DOI: 10.1136/jmg-2023-109340] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/11/2023] [Indexed: 09/23/2023]
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) is a mitochondrial disorder characterised by complex I defect leading to sudden degeneration of retinal ganglion cells. Although typically associated with pathogenic variants in mitochondrial DNA, LHON was recently described in patients carrying biallelic variants in nuclear genes DNAJC30, NDUFS2 and MCAT. MCAT is part of mitochondrial fatty acid synthesis (mtFAS), as also MECR, the mitochondrial trans-2-enoyl-CoA reductase. MECR mutations lead to a recessive childhood-onset syndromic disorder with dystonia, optic atrophy and basal ganglia abnormalities. METHODS We studied through whole exome sequencing two sisters affected by sudden and painless visual loss at young age, with partial recovery and persistent central scotoma. We modelled the candidate variant in yeast and studied mitochondrial dysfunction in yeast and fibroblasts. We tested protein lipoylation and cell response to oxidative stress in yeast. RESULTS Both sisters carried a homozygous pathogenic variant in MECR (p.Arg258Trp). In yeast, the MECR-R258W mutant showed an impaired oxidative growth, 30% reduction in oxygen consumption rate and 80% decrease in protein levels, pointing to structure destabilisation. Fibroblasts confirmed the reduced amount of MECR protein, but failed to reproduce the OXPHOS defect. Respiratory complexes assembly was normal. Finally, the yeast mutant lacked lipoylation of key metabolic enzymes and was more sensitive to H2O2 treatment. Lipoic Acid supplementation partially rescued the growth defect. CONCLUSION We report the first family with homozygous MECR variant causing an LHON-like optic neuropathy, which pairs the recent MCAT findings, reinforcing the impairment of mtFAS as novel pathogenic mechanism in LHON.
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Affiliation(s)
- Claudio Fiorini
- Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Andrea Degiorgi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Maria Lucia Cascavilla
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milano, Italy
| | | | - Chiara La Morgia
- Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Marco Battista
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Danara Ormanbekova
- Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Flavia Palombo
- Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Michele Carbonelli
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Francesco Bandello
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Valerio Carelli
- Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Alessandra Maresca
- Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Piero Barboni
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Leonardo Caporali
- Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
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Wang L, Ji Y, Ding H, Tian Q, Fan K, Shi D, Yu C, Qin W. Abnormal cerebral blood flow in patients with Leber's hereditary optic neuropathy. Brain Imaging Behav 2023; 17:471-480. [PMID: 37368154 DOI: 10.1007/s11682-023-00775-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2023] [Indexed: 06/28/2023]
Abstract
PURPOSE The study aimed to unravel abnormal cerebral blood flow (CBF) in patients with Leber's hereditary optic neuropathy (LHON) using arterial spin labeling (ASL) and to investigate the associations among disrupted CBF, disease duration, and neuro-ophthalmological impairment. METHODS ASL perfusion imaging data was collected from 20 patients with acute LHON, 29 patients with chronic LHON, and 37 healthy controls. We used a one-way analysis of covariance to test the intergroup differences in CBF. Linear and nonlinear curve fit models were applied to explore the associations among CBF, disease duration, and neuro-ophthalmological metrics. RESULTS Brain regions differed in LHON patients, including the left sensorimotor and bilateral visual areas (p < 0.05, cluster-wise family-wise error correction). Acute and chronic LHON patients demonstrated lower CBF in bilateral calcarine than the healthy controls. Chronic LHON had lower CBF in the left middle frontal gyrus and sensorimotor cortex, and temporal-partial junction than the healthy controls and acute LHON. A significant logarithmic negative correlation was shown between CBF of left middle frontal gyrus and disease duration. A significant linear positive correlation was found between retinal nerve fiber layer thickness and CBF in left middle frontal gyrus, and negative correlations between loss of variance and CBF in left middle frontal gyrus and sensorimotor cortex (p < 0.05, Bonferroni correction). CONCLUSION LHON patients exhibited reduced CBF in the visual pathway, sensorimotor and higher-tier cognitive areas. Disease duration and neuro-ophthalmological impairments can influence the metabolism of non-visual areas.
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Affiliation(s)
- Ling Wang
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou, 450003, China
| | - Yi Ji
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Hao Ding
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China
- School of Medical Imaging, Tianjin Medical University, Tianjin, 300070, China
| | - Qin Tian
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou, 450003, China
| | - Ke Fan
- Henan Eye Institute, Henan Eye Hospital, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, 450003, China
| | - Dapeng Shi
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou, 450003, China.
- Department of Medical Imaging, Henan Provincial People's Hospital, Sanquan College of Xinxiang Medical University, Weiwu Road No. 7, Jinshui District, ZhengZhou, Henan Province, China.
| | - Chunshui Yu
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China.
- Department of Radiology, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin, 300052, China.
| | - Wen Qin
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China.
- Department of Radiology, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin, 300052, China.
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Ji Y, Wang L, Ding H, Tian Q, Fan K, Shi D, Yu C, Qin W. Aberrant neurovascular coupling in Leber's hereditary optic neuropathy: Evidence from a multi-model MRI analysis. Front Neurosci 2023; 16:1050772. [PMID: 36703998 PMCID: PMC9871937 DOI: 10.3389/fnins.2022.1050772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
The study aimed to investigate the neurovascular coupling abnormalities in Leber's hereditary optic neuropathy (LHON) and their associations with clinical manifestations. Twenty qualified acute Leber's hereditary optic neuropathy (A-LHON, disease duration ≤ 1 year), 29 chronic Leber's hereditary optic neuropathy (C-LHON, disease duration > 1 year), as well as 37 healthy controls (HCs) were recruited. The neurovascular coupling strength was quantified as the ratio between regional homogeneity (ReHo), which represents intrinsic neuronal activity and relative cerebral blood flow (CBF), representing microcirculatory blood supply. A one-way analysis of variance was used to compare intergroup differences in ReHo/CBF ratio with gender and age as co-variables. Pearson's Correlation was used to clarify the association between ReHo, CBF, and neurovascular coupling strength. Furthermore, we applied linear and exponential non-linear regression models to explore the associations among ReHo/CBF, disease duration, and neuro-ophthalmological metrics. Compared with HCs, A_LHON, and C_LHON patients demonstrated a higher ReHo/CBF ratio than the HCs in the bilateral primary visual cortex (B_CAL), which was accompanied by reduced CBF while preserved ReHo. Besides, only C_LHON had a higher ReHo/CBF ratio and reduced CBF in the left middle temporal gyrus (L_MTG) and left sensorimotor cortex (L_SMC) than the HCs, which was accompanied by increased ReHo in L_MTG (p < 1.85e-3, Bonferroni correction). A-LHON and C-LHON showed a negative Pearson correlation between ReHo/CBF ratio and CBF in B_CAL, L_SMC, and L_MTG. Only C_LHON showed a weak positive correlation between ReHo/CBF ratio and ReHo in L_SMC and L_MTG (p < 0.05, uncorrected). Finally, disease duration was positively correlated with ReHo/CBF ratio of L_SMC (Exponential: Radj2 = 0.23, p = 8.66e-4, Bonferroni correction). No statistical correlation was found between ReHo/CBF ratio and neuro-ophthalmological metrics (p > 0.05, Bonferroni correction). Brain neurovascular "dyscoupling" within and outside the visual system might be an important neurological mechanism of LHON.
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Affiliation(s)
- Yi Ji
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Ling Wang
- Department of Medical Imaging, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Hao Ding
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China,School of Medical Imaging, Tianjin Medical University, Tianjin, China
| | - Qin Tian
- Department of Medical Imaging, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Ke Fan
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People’s Hospital, Zhengzhou University People’s Hospital, Zhengzhou, China
| | - Dapeng Shi
- Department of Medical Imaging, Henan Provincial People’s Hospital, Zhengzhou, China,*Correspondence: Dapeng Shi,
| | - Chunshui Yu
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China,Chunshui Yu,
| | - Wen Qin
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China,Wen Qin,
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Chow-Wing-Bom HT, Callaghan MF, Wang J, Wei S, Dick F, Yu-Wai-Man P, Dekker TM. Neuroimaging in Leber Hereditary Optic Neuropathy: State-of-the-art and future prospects. Neuroimage Clin 2022; 36:103240. [PMID: 36510411 PMCID: PMC9668671 DOI: 10.1016/j.nicl.2022.103240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 06/14/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
Leber Hereditary Optic Neuropathy (LHON) is an inherited mitochondrial retinal disease that causes the degeneration of retinal ganglion cells and leads to drastic loss of visual function. In the last decades, there has been a growing interest in using Magnetic Resonance Imaging (MRI) to better understand mechanisms of LHON beyond the retina. This is partially due to the emergence of gene-therapies for retinal diseases, and the accompanying expanded need for reliably quantifying and monitoring visual processing and treatment efficiency in patient populations. This paper aims to draw a current picture of key findings in this field so far, the challenges of using neuroimaging methods in patients with LHON, and important open questions that MRI can help address about LHON disease mechanisms and prognoses, including how downstream visual brain regions are affected by the disease and treatment and why, and how scope for neural plasticity in these pathways may limit or facilitate recovery.
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Affiliation(s)
- Hugo T Chow-Wing-Bom
- Institute of Ophthalmology, University College London (UCL), London, United Kingdom; Birkbeck/UCL Centre for NeuroImaging, London, United Kingdom.
| | - Martina F Callaghan
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Junqing Wang
- Department of Ophthalmology, The Chinese People's Liberation Army General Hospital, The Chinese People's Liberation Army Medical School, Beijing, China
| | - Shihui Wei
- Department of Ophthalmology, The Chinese People's Liberation Army General Hospital, The Chinese People's Liberation Army Medical School, Beijing, China
| | - Frederic Dick
- Birkbeck/UCL Centre for NeuroImaging, London, United Kingdom; Department of Psychological Sciences, Birkbeck, University of London, United Kingdom; Department of Experimental Psychology, UCL, London, United Kingdom
| | - Patrick Yu-Wai-Man
- Institute of Ophthalmology, University College London (UCL), London, United Kingdom; John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom; Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Tessa M Dekker
- Institute of Ophthalmology, University College London (UCL), London, United Kingdom; Birkbeck/UCL Centre for NeuroImaging, London, United Kingdom; Department of Experimental Psychology, UCL, London, United Kingdom
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Zanin J, Dhollander T, Rance G, Yu L, Lan L, Wang H, Lou X, Connelly A, Nayagam B, Wang Q. Fiber-Specific Changes in White Matter Microstructure in Individuals With X-Linked Auditory Neuropathy. Ear Hear 2021; 41:1703-1714. [PMID: 33136644 DOI: 10.1097/aud.0000000000000890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Auditory neuropathy (AN) is the term used to describe a group of hearing disorders, in which the hearing impairment occurs as a result of abnormal auditory nerve function. While our understanding of this condition has advanced significantly over recent years, the ability to determine the site of lesion and the extent of dysfunction in affected individuals remains a challenge. To this end, we investigated potential axonal degeneration in the white matter tracts of the brainstem in individuals with X-linked AN. We hypothesized that individuals with X-linked AN would show focal degeneration within the VIII nerve and/or auditory brainstem tracts, and the degree of degeneration would correlate with the extent of auditory perceptual impairment. DESIGN This was achieved using a higher-order diffusion magnetic resonance imaging (dMRI)-based quantitative measure called apparent fiber density as obtained from a technique called single-shell 3-tissue constrained spherical deconvolution and analyzed with the fixel-based analysis framework. Eleven subjects with genetically confirmed X-linked AN and 11 controls with normal hearing were assessed using behavioral and objective auditory measures. dMRI data were also collected for each participant. RESULTS Fixel-based analysis of the brainstem region showed that subjects with X-linked AN had significantly lower apparent fiber density in the VIII nerve compared with controls, consistent with axonal degeneration in this region. Subsequent analysis of the auditory brainstem tracts specifically showed that degeneration was also significant in these structures overall. The apparent fiber density findings were supported by objective measures of auditory function, such as auditory brainstem responses, electrocochleography, and otoacoustic emissions, which showed VIII nerve activity was severely disrupted in X-linked AN subjects while cochlear sensory hair cell function was relatively unaffected. Moreover, apparent fiber density results were significantly correlated with temporal processing ability (gap detection task) in affected subjects, suggesting that the degree of VIII nerve degeneration may impact the ability to resolve temporal aspects of an acoustic signal. Auditory assessments of sound detection, speech perception, and the processing of binaural cues were also significantly poorer in the X-linked AN group compared with the controls with normal hearing. CONCLUSIONS The results of this study suggest that the dMRI-based measure of apparent fiber density may provide a useful adjunct to existing auditory assessments in the characterization of the site of lesion and extent of dysfunction in individuals with AN. Additionally, the ability to determine the degree of degeneration has the potential to guide rehabilitation strategies in the future.
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Affiliation(s)
- Julien Zanin
- The HEARing Cooperative Research Centre (HEARing CRC), Melbourne, Victoria, Australia
- Department of Audiology and Speech Pathology, University of Melbourne, Parkville, Australia
| | - Thijs Dhollander
- Developmental Imaging, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Gary Rance
- The HEARing Cooperative Research Centre (HEARing CRC), Melbourne, Victoria, Australia
- Department of Audiology and Speech Pathology, University of Melbourne, Parkville, Australia
| | - Lan Yu
- Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese People's Liberation Army General Hospital 301, Beijing, China
- China National Clinical Research Centre for Otolaryngologic Diseases, Chinese People's Liberation Army General Hospital 301, Beijing, China
| | - Lan Lan
- Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese People's Liberation Army General Hospital 301, Beijing, China
- China National Clinical Research Centre for Otolaryngologic Diseases, Chinese People's Liberation Army General Hospital 301, Beijing, China
| | - Hongyang Wang
- Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese People's Liberation Army General Hospital 301, Beijing, China
- China National Clinical Research Centre for Otolaryngologic Diseases, Chinese People's Liberation Army General Hospital 301, Beijing, China
| | - Xin Lou
- Department of Radiology, Chinese People's Liberation Army General Hospital 301, Beijing, China
| | - Alan Connelly
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia
- The Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Bryony Nayagam
- Department of Audiology and Speech Pathology, University of Melbourne, Parkville, Australia
- These authors contributed equally to this work
| | - Qiuju Wang
- Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese People's Liberation Army General Hospital 301, Beijing, China
- China National Clinical Research Centre for Otolaryngologic Diseases, Chinese People's Liberation Army General Hospital 301, Beijing, China
- Key Lab of Hearing Impairment Science of Ministry of Education, Beijing, China
- These authors contributed equally to this work
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Wang L, Ding H, Chen BT, Fan K, Tian Q, Long M, Liang M, Shi D, Yu C, Qin W. Occult primary white matter impairment in Leber hereditary optic neuropathy. Eur J Neurol 2021; 28:2871-2881. [PMID: 34166558 DOI: 10.1111/ene.14995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/17/2021] [Accepted: 06/22/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Leber hereditary optic neuropathy (LHON) is a disease maternally inherited from mitochondria that predominantly impairs the retinal ganglion cells and their axons. To identify whether occult brain white matter (WM) impairment is involved, a voxel-based analysis (VBA) of diffusion metrics was carried out in LHON patients with normal-appearing brain parenchyma. METHODS Fifty-four symptomatic LHON patients (including 22 acute LHON with vision loss for ≤12 months, and 32 chronic LHON) without any visible brain lesions and 36 healthy controls (HCs) were enrolled in this study. VBA was applied to quantify the WM microstructural changes of LHON patients. Finally, the associations of the severity of WM impairment with disease duration and ophthalmologic deficits were assessed. RESULTS Compared with the HCs, the average retinal nerve fiber layer (RNFL) thickness was significantly reduced in patients with chronic LHON, whereas it was increased in patients with acute LHON (p < 0.05, corrected). VBA identified significantly decreased fractional anisotropy widely in WM in both the acute and chronic LHON patients, including the left anterior thalamic radiation and superior longitudinal fasciculus, and bilateral corticospinal tract, dentate nuclei, inferior longitudinal fasciculus, forceps major, and optic radiation (OR; p < 0.05, corrected). The integrity of most WM structures (except for the OR) was correlated with neither disease duration nor RNFL thickness (p > 0.05, corrected). CONCLUSIONS Occult primary impairment of widespread brain WM is present in LHON patients. The coexisting primary and secondary WM impairment may jointly contribute to the pathological process of LHON.
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Affiliation(s)
- Ling Wang
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou, China
| | - Hao Ding
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.,School of Medical Imaging, Tianjin Medical University, Tianjin, China
| | - Bihong T Chen
- Department of Diagnostic Radiology, City of Hope National Medical Center, Duarte, California, USA
| | - Ke Fan
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, Zhengzhou, China
| | - Qin Tian
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou, China
| | - Miaomiao Long
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China
| | - Meng Liang
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.,School of Medical Imaging, Tianjin Medical University, Tianjin, China
| | - Dapeng Shi
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou, China
| | - Chunshui Yu
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China
| | - Wen Qin
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China
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Zhang J, Wang L, Ding H, Fan K, Tian Q, Liang M, Sun Z, Shi D, Qin W. Abnormal large-scale structural rich club organization in Leber's hereditary optic neuropathy. NEUROIMAGE-CLINICAL 2021; 30:102619. [PMID: 33752075 PMCID: PMC8010853 DOI: 10.1016/j.nicl.2021.102619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/23/2021] [Accepted: 03/02/2021] [Indexed: 12/24/2022]
Abstract
LHON patients suffered large-scale structural network disruption. Non-rich club connections may be more vulnerable in the LHON. Both primary and secondary connectivity damage may coexist in the LHON.
Objective The purpose of this study was to investigate whether the large-scale structural rich club organization was abnormal in patients with Leber's hereditary optic neuropathy (LHON) using diffusion tensor imaging (DTI), and the associations among disrupted brain structural connectivity, disease duration, and neuro-ophthalmological impairment. Methods Nineteen acute, 34 chronic LHON patients, and 36 healthy controls (HC) underwent DTI and neuro-ophthalmological measurements. The brain structural network and rich club organization were constructed based on deterministic fiber tracking at the individual level. Then intergroup differences among the acute, chronic LHON patients and healthy controls (HC) in three types of structural connections, including rich club, feeder, and local ones, were compared. Network-based Statistics (NBS) was also used to test the intergroup connectivity differences for each fiber. Several linear and nonlinear curve fit models were applied to explore the associations among large-scale brain structural connectivity, disease duration, and neuro-ophthalmological metrics. Results Compared to the HC, both the acute and chronic LHON patients had consistently significantly lower fractional anisotropy (FA) and higher radial diffusion (RD) for feeder connections (p < 0.05, FDR correction). Acute LHON patients had significantly lower FA and higher RD for local connections (p < 0.05, FDR correction). There was no significant difference in large-scale brain structural connectivity between acute and chronic LHON (p > 0.05, FDR correction). NBS also identified reduced FA of three feeder connections and five local ones linking visual, auditory, and basal ganglia areas in LHON patients (p < 0.05, FDR correction). No structural connections showed linear or nonlinear association with either disease duration or neuro-ophthalmological indicators (p > 0.05, FDR correction). A significant negative correlation was shown between the retinal nerve fiber layer (RNFL) thickness and disease duration (p < 0.05, FDR correction). Conclusions Abnormal rich club organization of the structural network was identified in both the acute and chronic LHON. Furthermore, our findings suggest the coexistence of both primary and secondary connectivity damage in the LHON.
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Affiliation(s)
- Jiahui Zhang
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Ling Wang
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou 450003, China
| | - Hao Ding
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, China; School of Medical Imaging, Tianjin Medical University, Tianjin 300070, China
| | - Ke Fan
- Henan Eye Institute, Henan Eye Hospital, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou 450003, China
| | - Qin Tian
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou 450003, China
| | - Meng Liang
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, China; School of Medical Imaging, Tianjin Medical University, Tianjin 300070, China
| | - Zhihua Sun
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, China.
| | - Dapeng Shi
- Department of Medical Imaging, Henan Provincial People's Hospital, Zhengzhou 450003, China.
| | - Wen Qin
- Department of Radiology & Tianjin Key Lab of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, China.
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9
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Příhodová I, Nepožitek J, Kelifová S, Dostálová S, Kemlink D, Šonka K, Tesařová M, Honzík T, Kolářová H. Subjective and polysomnographic evaluation of sleep in mitochondrial optic neuropathies. J Sleep Res 2020; 30:e13051. [PMID: 32524698 DOI: 10.1111/jsr.13051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/18/2020] [Accepted: 03/24/2020] [Indexed: 11/26/2022]
Abstract
Leber hereditary optic neuropathy and Dominant optic atrophy are associated with a selective loss of retinal ganglion cells (RGC). A subtype of RGC is responsible for light-dependent physiological processes. The aim of our study was to evaluate both subjective and objective sleep parameters in 36 (18 males; mean age 33.8 ± 16.7) symptomatic/asymptomatic subjects with Leber hereditary optic neuropathy and dominant optic atrophy. The Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS) and nocturnal polysomnography were used to assess sleep disturbances and sleep quality. The questionnaires indicated significantly worse sleep quality (PSQI > 5; average 7.7 ± 3.8) in 21 (70%) and excessive daytime sleepiness (ESS > 10; average 6.3 ± 5.8) in six (20%) individuals. Nocturnal polysomnography has not revealed any significant changes of sleep structure. Rapid eye movement (REM) sleep without atonia was observed in two patients with Leber hereditary optic neuropathy. Obstructive sleep apnea was noted in eight cases. No correlation between subjective and polysomnographic data and no differences between symptomatic and asymptomatic groups were observed. None of the subjects fulfilled criteria for a circadian sleep disorder. In both symptomatic and asymptomatic individuals, a subjective decrease of the quality of sleep and wakefulness was noted without any correlation on polysomnography.
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Affiliation(s)
- Iva Příhodová
- Department of Neurology and Center for Clinical Neurosciences, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Jiří Nepožitek
- Department of Neurology and Center for Clinical Neurosciences, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Silvie Kelifová
- Department of Pediatrics and Adolescent Medicine, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Simona Dostálová
- Department of Neurology and Center for Clinical Neurosciences, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - David Kemlink
- Department of Neurology and Center for Clinical Neurosciences, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Karel Šonka
- Department of Neurology and Center for Clinical Neurosciences, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Markéta Tesařová
- Department of Pediatrics and Adolescent Medicine, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Tomáš Honzík
- Department of Pediatrics and Adolescent Medicine, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Hana Kolářová
- Department of Pediatrics and Adolescent Medicine, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
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10
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Jiang P, Zhang S, Cheng C, Gao S, Tang M, Lu L, Yang G, Chai R. The Roles of Exosomes in Visual and Auditory Systems. Front Bioeng Biotechnol 2020; 8:525. [PMID: 32582658 PMCID: PMC7283584 DOI: 10.3389/fbioe.2020.00525] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/04/2020] [Indexed: 12/16/2022] Open
Abstract
Exosomes are nanoscale membrane-enclosed vesicles 30-150 nm in diameter that are originated from a number of type cells by the endocytic pathway and consist of proteins, lipids, RNA, and DNA. Although, exosomes were initially considered to be cellular waste, they have gradually been recognized to join in cell-cell communication and cell signal transmission. In addition, exosomal contents can be applied as biomarkers for clinical judgment and exosomes can as potential carriers in a novel drug delivery system. Unfortunately, purification methods of exosomes remain an obstacle. We described some common purification methods and highlight Morpho Menelaus (M. Menelaus) butterfly wings can be developed as efficient methods for exosome isolation. Furthermore, the current research on exosomes mainly focused on their roles in cancer, while related studies on exosomes in the visual and auditory systems are limited. Here we reviewed the biogenesis and contents of exosomes. And more importantly, we summarized the roles of exosomes and provided prospective for exosome research in the visual and auditory systems.
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Affiliation(s)
- Pei Jiang
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Science and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Shasha Zhang
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Science and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Cheng Cheng
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, China.,Research Institute of Otolaryngology, Nanjing, China
| | - Song Gao
- Department of Otolaryngology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, China
| | - Mingliang Tang
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Science and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Institute for Cardiovascular Science, Department of Cardiovascular Surgery of the First Affiliated Hospital, Medical College, Soochow University, Suzhou, China
| | - Ling Lu
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, China
| | - Guang Yang
- Department of Otorhinolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China
| | - Renjie Chai
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Science and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
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11
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Long M, Wang L, Tian Q, Ding H, Qin W, Shi D, Yu C. Brain white matter changes in asymptomatic carriers of Leber’s hereditary optic neuropathy. J Neurol 2019; 266:1474-1480. [DOI: 10.1007/s00415-019-09284-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/13/2019] [Accepted: 03/15/2019] [Indexed: 10/27/2022]
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12
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Repetitive brainstem lesions in mitochondrial DNA 11778G>A mutation of Leber hereditary optic neuropathy. eNeurologicalSci 2019; 14:74-76. [PMID: 30705974 PMCID: PMC6348755 DOI: 10.1016/j.ensci.2019.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/27/2018] [Accepted: 01/07/2019] [Indexed: 11/21/2022] Open
Abstract
•LHON cases can show brainstem lesions without visual impairment.•There can be inconsistency between MRI finding and clinical symptom in LHON cases.•Auditory pathways may be often involved in LHON cases.
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13
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Finsterer J, Zarrouk-Mahjoub S. Leber's hereditary optic neuropathy is multiorgan not mono-organ. Clin Ophthalmol 2016; 10:2187-2190. [PMID: 27843288 PMCID: PMC5098596 DOI: 10.2147/opth.s120197] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disorder with bilateral loss of central vision primarily due to mitochondrial DNA (mtDNA) mutations in subunits of complex I in the respiratory chain (primary LHON mutations), while other mtDNA mutations can also be causative. Since the first description, it is known that LHON is not restricted to the eyes but is a multisystem disorder additionally involving the central nervous system, ears, endocrinological organs, heart, bone marrow, arteries, kidneys, or the peripheral nervous system. Multisystem involvement may start before or after the onset of visual impairment. Involvement of organs other than the eyes may be subclinical depending on age, ethnicity, and possibly the heteroplasmy rate of the responsible primary LHON mutation. Primary LHON mutations may rarely manifest without ocular compromise but with arterial hypertension, various neurodegenerative diseases, or Leigh syndrome. Patients with LHON need to be closely followed up to detect at which point organs other than the eyes become affected. Multiorgan disease in LHON often responds more favorably to symptomatic treatment than the ocular compromise.
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14
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Ng YS, Turnbull DM. Mitochondrial disease: genetics and management. J Neurol 2016; 263:179-91. [PMID: 26315846 PMCID: PMC4723631 DOI: 10.1007/s00415-015-7884-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/18/2015] [Accepted: 08/18/2015] [Indexed: 12/14/2022]
Abstract
Mitochondrial disease is one of the most common groups of genetic diseases with a minimum prevalence of greater than 1 in 5000 in adults. Whilst multi-system involvement is often evident, neurological manifestation is the principal presentation in most cases. The multiple clinical phenotypes and the involvement of both the mitochondrial and nuclear genome make mitochondrial disease particularly challenging for the clinician. In this review article we cover mitochondrial genetics and common neurological presentations associated with adult mitochondrial disease. In addition, specific and supportive treatments are discussed.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Doug M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
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15
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Rance G, Starr A. Pathophysiological mechanisms and functional hearing consequences of auditory neuropathy. Brain 2015; 138:3141-58. [PMID: 26463676 DOI: 10.1093/brain/awv270] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/05/2015] [Indexed: 01/19/2023] Open
Abstract
The effects of inner ear abnormality on audibility have been explored since the early 20th century when sound detection measures were first used to define and quantify 'hearing loss'. The development in the 1970s of objective measures of cochlear hair cell function (cochlear microphonics, otoacoustic emissions, summating potentials) and auditory nerve/brainstem activity (auditory brainstem responses) have made it possible to distinguish both synaptic and auditory nerve disorders from sensory receptor loss. This distinction is critically important when considering aetiology and management. In this review we address the clinical and pathophysiological features of auditory neuropathy that distinguish site(s) of dysfunction. We describe the diagnostic criteria for: (i) presynaptic disorders affecting inner hair cells and ribbon synapses; (ii) postsynaptic disorders affecting unmyelinated auditory nerve dendrites; (iii) postsynaptic disorders affecting auditory ganglion cells and their myelinated axons and dendrites; and (iv) central neural pathway disorders affecting the auditory brainstem. We review data and principles to identify treatment options for affected patients and explore their benefits as a function of site of lesion.
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Affiliation(s)
- Gary Rance
- 1 Department of Audiology and Speech Pathology, The University of Melbourne, 550 Swanston Street, Parkville 3010 Australia
| | - Arnold Starr
- 2 Department of Neurology, The University of California (Irvine), 200 S. Manchester Ave., Suite 206, Orange, CA 92868-4280, USA
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16
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Distributed abnormalities of brain white matter architecture in patients with dominant optic atrophy and OPA1 mutations. J Neurol 2015; 262:1216-27. [DOI: 10.1007/s00415-015-7696-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/27/2015] [Accepted: 02/27/2015] [Indexed: 01/08/2023]
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17
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Manners DN, Rizzo G, La Morgia C, Tonon C, Testa C, Barboni P, Malucelli E, Valentino ML, Caporali L, Strobbe D, Carelli V, Lodi R. Diffusion Tensor Imaging Mapping of Brain White Matter Pathology in Mitochondrial Optic Neuropathies. AJNR Am J Neuroradiol 2015; 36:1259-65. [PMID: 25792533 DOI: 10.3174/ajnr.a4272] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/05/2014] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND PURPOSE Brain white matter is frequently affected in mitochondrial diseases; optic atrophy gene 1-autosomal dominant optic atrophy and Leber hereditary optic neuropathy are the most frequent mitochondrial monosymptomatic optic neuropathies. In this observational study, brain white matter microstructure was characterized by DTI in patients with optic atrophy gene 1-autosomal dominant optic atrophy and Leber hereditary optic neuropathy, in relation to clinical and genetic features. MATERIALS AND METHODS Nineteen patients with optic atrophy gene 1-autosomal dominant optic atrophy and 17 with Leber hereditary optic neuropathy older than 18 years of age, all genetically diagnosed, and 19 healthy volunteers underwent DTI by using a 1.5T MR imaging scanner and neurologic and ophthalmologic assessments. Brain white matter DTI metrics were calculated for all participants, and, in patients, their correlations with genetics and clinical findings were calculated. RESULTS Compared with controls, patients with optic atrophy gene 1-autosomal dominant optic atrophy had an increased mean diffusivity in 29.2% of voxels analyzed within major white matter tracts distributed throughout the brain, while fractional anisotropy was reduced in 30.3% of voxels. For patients with Leber hereditary optic neuropathy, the proportion of altered voxels was only 0.5% and 5.5%, respectively, of which half was found within the optic radiation and 3.5%, in the smaller acoustic radiation. In almost all regions, fractional anisotropy diminished with age in patients with optic atrophy gene 1-autosomal dominant optic atrophy and correlated with average retinal nerve fiber layer thickness in several areas. Mean diffusivity increased in those with a missense mutation. Patients with Leber hereditary optic neuropathy taking idebenone had slightly milder changes. CONCLUSIONS Patients with Leber hereditary optic neuropathy had preferential involvement of the optic and acoustic radiations, consistent with trans-synaptic degeneration, whereas patients with optic atrophy gene 1-autosomal dominant optic atrophy presented with widespread involvement suggestive of a multisystemic, possibly a congenital/developmental, disorder. White matter changes in Leber hereditary optic neuropathy and optic atrophy gene 1-autosomal dominant optic atrophy may be exploitable as biomarkers.
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Affiliation(s)
- D N Manners
- From the Functional MR Unit (D.N.M., G.R., C.Tonon, C.Testa, R.L.)
| | - G Rizzo
- From the Functional MR Unit (D.N.M., G.R., C.Tonon, C.Testa, R.L.) Neurology Unit (G.R., C.L.M., M.L.V., L.C., D.S., V.C.), Department of Biomedical and NeuroMotor Sciences
| | - C La Morgia
- Neurology Unit (G.R., C.L.M., M.L.V., L.C., D.S., V.C.), Department of Biomedical and NeuroMotor Sciences "Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna" (C.L.M., M.L.V., L.C., D.S., V.C.), Bologna, Italy
| | - C Tonon
- From the Functional MR Unit (D.N.M., G.R., C.Tonon, C.Testa, R.L.)
| | - C Testa
- From the Functional MR Unit (D.N.M., G.R., C.Tonon, C.Testa, R.L.)
| | - P Barboni
- Studio Oculistico d'Azeglio (P.B.), Bologna, Italy
| | - E Malucelli
- Department of Pharmacy and Biotechnology (E.M.), University of Bologna, Bologna, Italy
| | - M L Valentino
- Neurology Unit (G.R., C.L.M., M.L.V., L.C., D.S., V.C.), Department of Biomedical and NeuroMotor Sciences "Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna" (C.L.M., M.L.V., L.C., D.S., V.C.), Bologna, Italy
| | - L Caporali
- Neurology Unit (G.R., C.L.M., M.L.V., L.C., D.S., V.C.), Department of Biomedical and NeuroMotor Sciences "Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna" (C.L.M., M.L.V., L.C., D.S., V.C.), Bologna, Italy
| | - D Strobbe
- Neurology Unit (G.R., C.L.M., M.L.V., L.C., D.S., V.C.), Department of Biomedical and NeuroMotor Sciences "Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna" (C.L.M., M.L.V., L.C., D.S., V.C.), Bologna, Italy
| | - V Carelli
- Neurology Unit (G.R., C.L.M., M.L.V., L.C., D.S., V.C.), Department of Biomedical and NeuroMotor Sciences "Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna" (C.L.M., M.L.V., L.C., D.S., V.C.), Bologna, Italy
| | - R Lodi
- From the Functional MR Unit (D.N.M., G.R., C.Tonon, C.Testa, R.L.)
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18
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Recent advances in clinical neurogenetics. J Neurol 2013; 260:2451-7. [DOI: 10.1007/s00415-012-6757-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/06/2012] [Accepted: 11/09/2012] [Indexed: 11/24/2022]
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19
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Kennerson ML, Yiu EM, Chuang DT, Kidambi A, Tso SC, Ly C, Chaudhry R, Drew AP, Rance G, Delatycki MB, Züchner S, Ryan MM, Nicholson GA. A new locus for X-linked dominant Charcot-Marie-Tooth disease (CMTX6) is caused by mutations in the pyruvate dehydrogenase kinase isoenzyme 3 (PDK3) gene. Hum Mol Genet 2013; 22:1404-16. [PMID: 23297365 PMCID: PMC3596851 DOI: 10.1093/hmg/dds557] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/16/2012] [Accepted: 12/27/2012] [Indexed: 01/30/2023] Open
Abstract
Hereditary motor and sensory disorders of the peripheral nerve form one of the most common groups of human genetic diseases collectively called Charcot-Marie-Tooth (CMT) neuropathy. Using linkage analysis in a three generation kindred, we have mapped a new locus for X-linked dominant CMT to chromosome Xp22.11. A microsatellite scan of the X chromosome established significant linkage to several markers including DXS993 (Zmax = 3.16; θ = 0.05). Extended haplotype analysis refined the linkage region to a 1.43-Mb interval flanked by markers DXS7110 and DXS8027. Whole exome sequencing identified a missense mutation c.G473A (p.R158H) in the pyruvate dehydrogenase kinase isoenzyme 3 (PDK3) gene. The change localized within the 1.43-Mb linkage interval, segregated with the affected phenotype and was excluded in ethnically matched control chromosomes. PDK3 is one of the four isoenzymes regulating the pyruvate dehydrogenase complex (PDC), by reversible phosphorylation, and is a nuclear-coded protein located in the mitochondrial matrix. PDC catalyzes the oxidative decarboxylation of pyruvate to acetyl CoA and is a key enzyme linking glycolysis to the energy-producing Krebs cycle and lipogenic pathways. We found that the R158H mutation confers enzyme hyperactivity and binds with stronger affinity than the wild-type to the inner-lipoyl (L2) domain of the E2p chain of PDC. Our findings suggest a reduced pyruvate flux due to R158H mutant PDK3-mediated hyper-phosphorylation of the PDC as the underlying pathogenic cause of peripheral neuropathy. The results highlight an important causative link between peripheral nerve degeneration and an essential bioenergetic or biosynthetic pathway required for the maintenance of peripheral nerves.
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Affiliation(s)
- Marina L Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord, NSW, Australia.
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20
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Leruez S, Milea D, Defoort-Dhellemmes S, Colin E, Crochet M, Procaccio V, Ferré M, Lamblin J, Drouin V, Vincent-Delorme C, Lenaers G, Hamel C, Blanchet C, Juul G, Larsen M, Verny C, Reynier P, Amati-Bonneau P, Bonneau D. Sensorineural hearing loss in OPA1-linked disorders. Brain 2013; 136:e236. [DOI: 10.1093/brain/aws340] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Rance G, Ryan M, Carew P, Corben L, Yiu E, Tan J, Delatycki M. Binaural speech processing in individuals with auditory neuropathy. Neuroscience 2012; 226:227-35. [DOI: 10.1016/j.neuroscience.2012.08.054] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 08/20/2012] [Accepted: 08/26/2012] [Indexed: 10/27/2022]
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Tarnutzer AA, Straumann D. Progress in neuro-otology research in the last year. J Neurol 2012; 259:2506-9. [PMID: 22983429 DOI: 10.1007/s00415-012-6670-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 09/01/2012] [Accepted: 09/03/2012] [Indexed: 11/26/2022]
Abstract
Herein, we summarize articles in the field of neuro-otology published in the Journal of Neurology over the last year. Topics included acute and chronic vertigo as well as auditory and ocular motor disorders. Characteristic lesion locations in Pusher syndrome are reported and the usefulness of bedside ocular motor tests in vertebrobasilar stroke is revisited. Probing the vestibular system and its value in predicting the outcome in vegetative state is discussed. Several articles address new diagnostic and therapeutic approaches in different disorders associated with chronic vestibular, auditory or gait deficits. In a series of case reports, we focus on different eye movement disorders in the vertical plane, which are often difficult to assess.
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Affiliation(s)
- Alexander A Tarnutzer
- Department of Neurology, University Hospital Zurich, Frauenklinikstrasse 26, 8091, Zurich, Switzerland.
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Rance G, Ryan MM, Bayliss K, Gill K, O'Sullivan C, Whitechurch M. Auditory function in children with Charcot-Marie-Tooth disease. Brain 2012; 135:1412-22. [PMID: 22522939 DOI: 10.1093/brain/aws085] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The peripheral manifestations of the inherited neuropathies are increasingly well characterized, but their effects upon cranial nerve function are not well understood. Hearing loss is recognized in a minority of children with this condition, but has not previously been systemically studied. A clear understanding of the prevalence and degree of auditory difficulties in this population is important as hearing impairment can impact upon speech/language development, social interaction ability and educational progress. The aim of this study was to investigate auditory pathway function, speech perception ability and everyday listening and communication in a group of school-aged children with inherited neuropathies. Twenty-six children with Charcot-Marie-Tooth disease confirmed by genetic testing and physical examination participated. Eighteen had demyelinating neuropathies (Charcot-Marie-Tooth type 1) and eight had the axonal form (Charcot-Marie-Tooth type 2). While each subject had normal or near-normal sound detection, individuals in both disease groups showed electrophysiological evidence of auditory neuropathy with delayed or low amplitude auditory brainstem responses. Auditory perception was also affected, with >60% of subjects with Charcot-Marie-Tooth type 1 and >85% of Charcot-Marie-Tooth type 2 suffering impaired processing of auditory temporal (timing) cues and/or abnormal speech understanding in everyday listening conditions.
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Affiliation(s)
- Gary Rance
- Department of Audiology and Speech Pathology, The University of Melbourne, 550 Swanston Street, Parkville 3010, Australia.
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