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de Rodez Benavent SA, Nygaard GO, Nilsen KB, Etholm L, Sowa P, Wendel-Haga M, Harbo HF, Drolsum L, Laeng B, Kerty E, Celius EG. Neurodegenerative Interplay of Cardiovascular Autonomic Dysregulation and the Retina in Early Multiple Sclerosis. Front Neurol 2019; 10:507. [PMID: 31156539 PMCID: PMC6529954 DOI: 10.3389/fneur.2019.00507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/26/2019] [Indexed: 11/27/2022] Open
Abstract
Introduction: Autonomic nervous system (ANS) symptoms are prevalent in multiple sclerosis (MS) as is neurodegeneration. Our aim was to explore the occurrence of ANS symptoms and retinal neurodegeneration in a newly diagnosed MS population with tools available in a clinical setting. Methods: Forty-three MS patients and 44 healthy controls took part in the study. We employed a bedside cardiovascular ANS test battery together with classical pupillometry, optical coherence tomography (OCT) evaluation of retinal neurodegeneration in eyes without previous optic neuritis (MSNON) and patients' self-report forms on fatigue, orthostatic and ANS symptoms. Results: Half of the patients presented with ANS symptoms and a high level of fatigue. There was a significant difference in ganglion cell layer thickness (mean GCIPL) evaluated by OCT in MSNON compared to healthy control eyes. We found a negative linearity of mean GCIPL on group level with increasing disease duration. Three patients fulfilled the criteria of postural orthostatic tachycardia syndrome (POTS). Conclusion: Our results demonstrate retinal neurodegeneration in MSNON, a high frequency of fatigue and a high prevalence of ANS symptoms in newly diagnosed patients. Whether neurodegeneration precedes ANS dysfunction or vice versa is still open to debate, but as unveiled by the presence of POTS in this MS population, differences in stress-response regulation add to the understanding of variation in onset-time of ANS dysfunction in early MS.
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Affiliation(s)
- Sigrid A de Rodez Benavent
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.,Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Gro O Nygaard
- Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Kristian B Nilsen
- Section for Clinical Neurophysiology, Department of Neurology, Oslo University Hospital, Oslo, Norway.,Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Lars Etholm
- Section for Clinical Neurophysiology, Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Piotr Sowa
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Marte Wendel-Haga
- Department of Neurology, Oslo University Hospital, Oslo, Norway.,Department of Neurology, Telemark Hospital, Skien, Norway
| | - Hanne F Harbo
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Liv Drolsum
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.,Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Bruno Laeng
- Department of Psychology, University of Oslo, Oslo, Norway
| | - Emilia Kerty
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Elisabeth G Celius
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
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Rukmini AV, Milea D, Gooley JJ. Chromatic Pupillometry Methods for Assessing Photoreceptor Health in Retinal and Optic Nerve Diseases. Front Neurol 2019; 10:76. [PMID: 30809186 PMCID: PMC6379484 DOI: 10.3389/fneur.2019.00076] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/21/2019] [Indexed: 12/19/2022] Open
Abstract
The pupillary light reflex is mediated by melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs), which also receive input from rods and cones. Melanopsin-dependent pupillary light responses are short-wavelength sensitive, have a higher threshold of activation, and are much slower to activate and de-activate compared with rod/cone-mediated responses. Given that rod/cone photoreceptors and melanopsin differ in their response properties, light stimuli can be designed to stimulate preferentially each of the different photoreceptor types, providing a read-out of their function. This has given rise to chromatic pupillometry methods that aim to assess the health of outer retinal photoreceptors and ipRGCs by measuring pupillary responses to blue or red light stimuli. Here, we review different types of chromatic pupillometry protocols that have been tested in patients with retinal or optic nerve disease, including approaches that use short-duration light exposures or continuous exposure to light. Across different protocols, patients with outer retinal disease (e.g., retinitis pigmentosa or Leber congenital amaurosis) show reduced or absent pupillary responses to dim blue-light stimuli used to assess rod function, and reduced responses to moderately-bright red-light stimuli used to assess cone function. By comparison, patients with optic nerve disease (e.g., glaucoma or ischemic optic neuropathy, but not mitochondrial disease) show impaired pupillary responses during continuous exposure to bright blue-light stimuli, and a reduced post-illumination pupillary response after light offset, used to assess melanopsin function. These proof-of-concept studies demonstrate that chromatic pupillometry methods can be used to assess damage to rod/cone photoreceptors and ipRGCs. In future studies, it will be important to determine whether chromatic pupillometry methods can be used for screening and early detection of retinal and optic nerve diseases. Such methods may also prove useful for objectively evaluating the degree of recovery to ipRGC function in blind patients who undergo gene therapy or other treatments to restore vision.
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Affiliation(s)
- A V Rukmini
- Programme in Neuroscience and Behavioural Disorders, Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, Singapore
| | - Dan Milea
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore.,The Ophthalmology and Visual Sciences Academic Clinical Programme (EYE-ACP), SingHealth and Duke-NUS, Singapore, Singapore
| | - Joshua J Gooley
- Programme in Neuroscience and Behavioural Disorders, Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, Singapore
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3
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Meltzer E, Sguigna PV, Subei A, Beh S, Kildebeck E, Conger D, Conger A, Lucero M, Frohman BS, Frohman AN, Saidha S, Galetta S, Calabresi PA, Rennaker R, Frohman TC, Kardon RH, Balcer LJ, Frohman EM. Retinal Architecture and Melanopsin-Mediated Pupillary Response Characteristics: A Putative Pathophysiologic Signature for the Retino-Hypothalamic Tract in Multiple Sclerosis. JAMA Neurol 2017; 74:574-582. [PMID: 28135360 PMCID: PMC5822208 DOI: 10.1001/jamaneurol.2016.5131] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 10/21/2016] [Indexed: 12/19/2022]
Abstract
Importance A neurophysiologic signature of the melanopsin-mediated persistent constriction phase of the pupillary light reflex may represent a surrogate biomarker for the integrity of the retinohypothalamic tract, with potential utility for investigating alterations in homeostatic mechanisms associated with brain disorders and implications for identifying new treatments. Objective To characterize abnormalities of retinal architecture in patients with multiple sclerosis (MS) and corresponding alterations in the melanopsin-mediated sustained pupillary constriction response. Design, Setting, and Participants The case-control study was an experimental assessment of various stimulus-induced pupillary response characteristics and was conducted at a university clinical center for MS from September 6, 2012, to February 2015. Twenty-four patients with MS (48 eyes) and 15 individuals serving as controls (30 eyes) participated. The melanopsin-mediated, sustained pupillary constriction phase response following cessation of a blue light stimulus was compared with the photoreceptor-mediated pupillary constriction phase response following cessation of a red light stimulus. Optical coherence tomography was used to characterize the association between pupillary response characteristics and alterations in retinal architecture, specifically, the thickness of the retinal ganglion cell layer and inner plexiform layer (GCL + IPL). Main Outcomes and Measures Association of pupillary response characteristics with alterations in retinal architecture. Results Of 24 patients with MS included in the analysis, 17 were women (71%); mean (SD) age was 47 (11) years. Compared with eyes from individuals with MS who had normal optical coherence tomography-derived measures of retinal GCL + IPL thickness, eyes of patients who had GCL + IPL thickness reductions to less than the first percentile exhibited a correspondingly significant attenuation of the melanopsin-mediated sustained pupillary response (mean [SD] pupillary diameter ratios at a point in time, 0.18 [0.1] vs 0.33 [0.09]; P < .001, generalized estimating equation models accounting for age and within-patient intereye correlations). Conclusions and Relevance In this case-control study, attenuation of the melanopsin-mediated sustained pupillary constriction response was significantly associated with thinning of the GCL + IPL sector of the retina in the eyes of patients with MS, particularly those with a history of acute optic neuritis. Melanopsin-containing ganglion cells in the retina represent, at least in part, the composition of the retinohypothalamic tract. As such, our findings may signify the ability to elucidate a putative surrogate neurophysiologic signature that correlates with a constellation of homeostatic mechanisms in both health and illness.
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Affiliation(s)
- Ethan Meltzer
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Peter V. Sguigna
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Adnan Subei
- Department of Neurology, Michigan State University, East Lansing
| | - Shin Beh
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Eric Kildebeck
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
- Center for Engineering Innovation, University of Texas at Dallas
| | - Darrel Conger
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Amy Conger
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Marlen Lucero
- Student, Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Benjamin S. Frohman
- Student, Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Ashley N. Frohman
- Student, Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Shiv Saidha
- Department of Neurology, Johns Hopkins Hospital, Baltimore, Maryland
| | - Steven Galetta
- Department of Neurology, Population Health, New York University School of Medicine, New York
| | | | | | - Teresa C. Frohman
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
| | - Randy H. Kardon
- Department of Ophthalmology, University of Iowa, Iowa City
- Iowa City Veterans Affairs Center for Prevention and Treatment of Visual Loss, Iowa City
| | - Laura J. Balcer
- Department of Neurology, Population Health, New York University School of Medicine, New York
- Department of Ophthalmology, New York University School of Medicine, New York
| | - Elliot M. Frohman
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas
- Department of Bioengineering, University of Texas at Dallas
- Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas
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4
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Balcer LJ, Raynowska J, Nolan R, Galetta SL, Kapoor R, Benedict R, Phillips G, LaRocca N, Hudson L, Rudick R. Validity of low-contrast letter acuity as a visual performance outcome measure for multiple sclerosis. Mult Scler 2017; 23:734-747. [PMID: 28206829 PMCID: PMC5407511 DOI: 10.1177/1352458517690822] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Low-contrast letter acuity (LCLA) has emerged as the leading outcome measure to assess visual disability in multiple sclerosis (MS) research. As visual dysfunction is one of the most common manifestations of MS, sensitive visual outcome measures are important in examining the effect of treatment. Low-contrast acuity captures visual loss not seen in high-contrast visual acuity (HCVA) measurements. These issues are addressed by the MS Outcome Assessments Consortium (MSOAC), including representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. MSOAC goals are acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are clinically meaningful. This review shows that MS and disease-free controls have similar median HCVA, while MS patients have significantly lower LCLA. Deficits in LCLA and vision-specific quality of life are found many years after an episode of acute optic neuritis, even when HCVA has recovered. Studies reveal correlations between LCLA and the Expanded Disability Status Score (EDSS), Multiple Sclerosis Functional Composite (MSFC), retinal nerve fiber layer (RNFL) and ganglion cell layer plus inner plexiform layer (GCL + IPL) thickness on optical coherence tomography (OCT), brain magnetic resonance imaging (MRI), visual evoked potential (VEP), electroretinogram (ERG), pupillary function, and King-Devick testing. This review also concludes that a 7-point change in LCLA is clinically meaningful. The overall goal of this review is to describe and characterize the LCLA metric for research and clinical use among persons with MS.
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Affiliation(s)
- Laura J Balcer
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Jenelle Raynowska
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Rachel Nolan
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Steven L Galetta
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Raju Kapoor
- National Hospital for Neurology and Neurosurgery, London, UK
| | - Ralph Benedict
- Department of Neurology, University at Buffalo, Buffalo, NY, USA
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- Multiple Sclerosis Outcome Assessments Consortium (MSOAC), Critical Path Institute, Tucson, AZ, USA
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5
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Pintér A, Cseh D, Sárközi A, Illigens BM, Siepmann T. Autonomic Dysregulation in Multiple Sclerosis. Int J Mol Sci 2015; 16:16920-52. [PMID: 26213927 PMCID: PMC4581177 DOI: 10.3390/ijms160816920] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 07/13/2015] [Accepted: 07/20/2015] [Indexed: 02/07/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic, progressive central neurological disease characterized by inflammation and demyelination. In patients with MS, dysregulation of the autonomic nervous system may present with various clinical symptoms including sweating abnormalities, urinary dysfunction, orthostatic dysregulation, gastrointestinal symptoms, and sexual dysfunction. These autonomic disturbances reduce the quality of life of affected patients and constitute a clinical challenge to the physician due to variability of clinical presentation and inconsistent data on diagnosis and treatment. Early diagnosis and initiation of individualized interdisciplinary and multimodal strategies is beneficial in the management of autonomic dysfunction in MS. This review summarizes the current literature on the most prevalent aspects of autonomic dysfunction in MS and provides reference to underlying pathophysiological mechanisms as well as means of diagnosis and treatment.
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Affiliation(s)
- Alexandra Pintér
- Institute of Human Physiology and Clinical Experimental Research, Faculty of Medicine, Semmelweis University, Budapest 1085, Hungary.
- Center for Clinical Research and Management Education, Division of Health Care Sciences, Dresden International University, Dresden 01067, Germany.
| | - Domonkos Cseh
- Institute of Human Physiology and Clinical Experimental Research, Faculty of Medicine, Semmelweis University, Budapest 1085, Hungary.
| | - Adrienn Sárközi
- Institute of Human Physiology and Clinical Experimental Research, Faculty of Medicine, Semmelweis University, Budapest 1085, Hungary.
| | - Ben M Illigens
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Timo Siepmann
- Center for Clinical Research and Management Education, Division of Health Care Sciences, Dresden International University, Dresden 01067, Germany.
- Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden 01307, Germany.
- Department of Psychotherapy and Psychosomatic Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden 01307, Germany.
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6
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Bennett JL, Nickerson M, Costello F, Sergott RC, Calkwood JC, Galetta SL, Balcer LJ, Markowitz CE, Vartanian T, Morrow M, Moster ML, Taylor AW, Pace TWW, Frohman T, Frohman EM. Re-evaluating the treatment of acute optic neuritis. J Neurol Neurosurg Psychiatry 2015; 86:799-808. [PMID: 25355373 PMCID: PMC4414747 DOI: 10.1136/jnnp-2014-308185] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 09/28/2014] [Indexed: 12/28/2022]
Abstract
Clinical case reports and prospective trials have demonstrated a reproducible benefit of hypothalamic-pituitary-adrenal (HPA) axis modulation on the rate of recovery from acute inflammatory central nervous system (CNS) demyelination. As a result, corticosteroid preparations and adrenocorticotrophic hormones are the current mainstays of therapy for the treatment of acute optic neuritis (AON) and acute demyelination in multiple sclerosis.Despite facilitating the pace of recovery, HPA axis modulation and corticosteroids have failed to demonstrate long-term benefit on functional recovery. After AON, patients frequently report visual problems, motion perception difficulties and abnormal depth perception despite 'normal' (20/20) vision. In light of this disparity, the efficacy of these and other therapies for acute demyelination require re-evaluation using modern, high-precision paraclinical tools capable of monitoring tissue injury.In no arena is this more amenable than AON, where a new array of tools in retinal imaging and electrophysiology has advanced our ability to measure the anatomic and functional consequences of optic nerve injury. As a result, AON provides a unique clinical model for evaluating the treatment response of the derivative elements of acute inflammatory CNS injury: demyelination, axonal injury and neuronal degeneration.In this article, we examine current thinking on the mechanisms of immune injury in AON, discuss novel technologies for the assessment of optic nerve structure and function, and assess current and future treatment modalities. The primary aim is to develop a framework for rigorously evaluating interventions in AON and to assess their ability to preserve tissue architecture, re-establish normal physiology and restore optimal neurological function.
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Affiliation(s)
- Jeffrey L Bennett
- Departments of Neurology and Ophthalmology, University of Colorado, Denver, Colorado, USA
| | - Molly Nickerson
- Department of Medical Affairs, Questcor Pharmaceuticals, Inc., Hayward, California, USA
| | - Fiona Costello
- Departments of Clinical Neurosciences and Surgery, University of Calgary, Hotchkiss Brain Institute, Alberta, Canada
| | - Robert C Sergott
- Neuro-Ophthalmology Service, Wills Eye Institute, Thomas Jefferson University Medical College, Philadelphia, Pennsylvania, USA
| | | | - Steven L Galetta
- Department of Neurology, Division of Neuro-Ophthalmology, NYU Langone Medical Center, New York, USA
| | - Laura J Balcer
- Department of Neurology, Division of Neuro-Ophthalmology, NYU Langone Medical Center, New York, USA
| | - Clyde E Markowitz
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Timothy Vartanian
- Rockefeller University and Memorial Sloan-Kettering Hospital, Weill Cornell Medical College, New York, USA
| | - Mark Morrow
- Department of Neurology, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
| | - Mark L Moster
- Neuro-Ophthalmology Service, Wills Eye Institute, Thomas Jefferson University Medical College, Philadelphia, Pennsylvania, USA
| | - Andrew W Taylor
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Thaddeus W W Pace
- College of Nursing at the University of Arizona, Tucson, Arizona, USA
| | - Teresa Frohman
- Departments of Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Elliot M Frohman
- Departments of Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA Departments of Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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7
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Blazek P, Davis SL, Greenberg BM, Conger A, Conger D, Vernino S, Beh S, Stuve O, Saidha S, Ratchford JN, Green A, Calabresi PA, Balcer LJ, Frohman TC, Frohman EM. Objective characterization of the relative afferent pupillary defect in MS. J Neurol Sci 2012; 323:193-200. [PMID: 23026533 DOI: 10.1016/j.jns.2012.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Revised: 09/11/2012] [Accepted: 09/12/2012] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To develop an objective and precise neurophysiologic method from which to identify and characterize the presence and magnitude of relative afferent pupillary defects (RAPD) in patients with MS. METHODS Binocular infrared pupillometry was performed in 40 control subjects and 32 MS patients with RAPDs, using two precisely defined sequences of alternating light flashes (right-left and left-right). We analyzed three distinct pupillary metrics in response to light stimulation. These included percent diameter change (DC), constriction curve area (CCA), which measures change in diameter over time, and the phase-plane curve area (PCA) which measures change in diameter with change in velocity. Direct and consensual response ratios (for each eye) were computed and analyzed for each metric in response to both the first flash (i.e. first phase) and second flash (i.e. second phase) of the 'swinging flashlight' test. RESULTS Second flash pupillary response metric asymmetry ratios yielded the highest discriminatory power for RAPD detection. Receiver operating characteristic areas under the curve for each of the pupillary metric response asymmetry ratios were as follows: diameter change: 0.97; constriction curve area: 0.96; phase-plane curve area: 0.95 (p<0.0001 for all comparisons compared to normal subjects). The sum of these three squared ratios (SSR) yielded a combined metric with the greatest discriminatory power (receiver operator characteristic area under the curve=0.99). CONCLUSIONS Second flash (i.e. the second phase of the swinging light test) pupillary metric response asymmetry ratios are highly sensitive and specific for the confirmation and characterization of an RAPD in patients with MS. This objective neurophysiologic method may be useful for studying the relationship between a stereotyped reflex, and nervous system architecture, with potential ramifications for detecting and monitoring neuroprotective and restorative effects of novel agents in MS treatment trials.
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Affiliation(s)
- Paul Blazek
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, USA
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8
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[Optical coherence tomography in neuro-ophthalmology]. J Fr Ophtalmol 2012; 35:454-66. [PMID: 22677462 DOI: 10.1016/j.jfo.2012.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 02/22/2012] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Optical coherence tomography (OCT) is a potential tool for diagnosis and follow-up in diseases of the anterior visual pathway in that it provides a reproducible and reliable quantification of retinal nerve fiber layer (RNFL) thickness. A review of the literature was conducted to define the utility of OCT in neuro-ophthalmology. MATERIALS AND METHODS The clinical applications of RNFL thickness measurement by OCT time domain were analyzed. The PubMed search engine enabled us to select the relevant publications, using the following keywords: "optic neuropathy", "retinal nerve fiber layer thickness", and "optical coherence tomography". Publications concerning glaucoma were excluded from this review. RESULTS The course of RNFL thickness depends on the underlying disease: (I) progressive reduction toward atrophy (e.g., optic neuritis, chiasmal compression) or (II) initial increase in RNFL thickness followed by a reduction toward (IIa) normalization (papilledema) or (IIb) atrophy (anterior ischemic optic neuropathy, Leber hereditary optic neuropathy). DISCUSSION Depending on the type of anterior visual pathway impairment, OCT provides RNFL data relevant for diagnosis, follow-up, and prognosis. As in macular disease, OCT has become an important clinical tool for routine disease assessment in neuro-ophthalmology.
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9
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Shindler KS, Revere K, Dutt M, Ying GS, Chung DC. In vivo detection of experimental optic neuritis by pupillometry. Exp Eye Res 2012; 100:1-6. [PMID: 22561341 DOI: 10.1016/j.exer.2012.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 03/30/2012] [Accepted: 04/13/2012] [Indexed: 11/19/2022]
Abstract
Optic neuritis is an inflammatory demyelination of optic nerve often occurring in multiple sclerosis (MS) patients. Mice with experimental autoimmune encephalomyelitis (EAE), an MS model, develop optic neuritis, but it is detected histologically after sacrifice, limiting the ability to monitor progression or treatment in vivo. We examined whether pupillary light responses measured by pupillometry can identify eyes with optic neuritis in EAE mice. C57BL/6 mice were exposed to unilateral light flashes of increasing intensity at 10 s intervals (4.7, 37, and 300 μW/cm(2)). Pupillary responses were recorded with a commercially available pupillometer. EAE was then induced by immunization with myelin oligodendrocyte glycoprotein. Pupillometry was repeated up to 17 days post-immunization, and responses were correlated with optic nerve inflammation. By day 17 post-immunization, 90% of EAE eyes had optic nerve inflammation. EAE eyes had significantly reduced pupillary constriction compared to control eyes. Mice exhibited more than a 25% decrease in pupillary constriction in at least one eye by days 13-15 post-immunization. In some eyes, pupil responses decreased prior to onset of detectable inflammation. Results show that pupillometry detects decreased optic nerve function in experimental optic neuritis, even in the absence of histological detection. Measuring pupillary constriction allows in vivo identification and functional assessment of eyes with optic neuritis that will be useful in evaluating potential therapies over time. Furthermore, results demonstrate that decreased visual function occurs early in optic neuritis, before optic nerve inflammation reaches its peak level.
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Affiliation(s)
- Kenneth S Shindler
- F.M. Kirby Center for Molecular Ophthalmology, Department of Ophthalmology, University of Pennsylvania Scheie Eye Institute, Stellar-Chance Laboratories, 3rd Floor, 422 Curie Blvd, Philadelphia, PA 19104, USA
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10
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Vision in multiple sclerosis: the story, structure-function correlations, and models for neuroprotection. J Neuroophthalmol 2012; 31:362-73. [PMID: 22089500 DOI: 10.1097/wno.0b013e318238937f] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Visual dysfunction is one of the most common clinical manifestations of multiple sclerosis (MS). Just over a decade ago, MS clinical trials did not include visual outcomes, but experts recognized the need for more sensitive measures of visual function. Low-contrast letter acuity emerged as the leading candidate to measure visual disability in MS, and subsequent studies found low-contrast acuity testing to correlate well with brain MRI lesion burden, visual-evoked potentials, quality of life (QOL), and retinal nerve fiber layer (RNFL) loss, as measured by optical coherence tomography (OCT). OCT in MS has allowed for assessment of structure-function correlations that make the anterior visual pathway and acute optic neuritis (ON) ideal models for testing novel agents for neuroprotection and repair. New therapies that reduce axonal loss by neuroprotective or myelin repair mechanisms can now be assessed noninvasively by OCT and coupled with visual function data. Based on OCT studies in MS, RNFL thickness is reduced significantly among patients (92 μm) vs controls (105 μm) and is particularly reduced in MS eyes with a history of ON (85 μm). Worsening of visual function by a clinically significant ≥ 7 letters or approximately 1.5 lines for low-contrast acuity is associated with approximately 4.5 μm reductions in RNFL thickness in MS eyes. Longitudinal studies of OCT have also shown RNFL axonal loss over time that occurs even in the absence of acute ON and that correlates with clinically meaningful worsening of vision and QOL, even in patients with benign MS. The latest OCT investigations involve high-resolution spectral-domain (SD) OCT with segmentation and measurement of specific retinal layers using computerized algorithms. These methods allow quantitation of ganglion cell (neuronal) layer loss and axonal degeneration in MS in vivo. In this review, we examine the data from these studies and ongoing trials that highlight the entity of ON as a model to investigate neuroprotection and neurorepair. In doing so, we also present representative group data from studies that have examined visual function, OCT measures, and QOL scales in patients with MS and ON and disease-free controls. These data, and those from recent meta-analyses, may be used to provide reference values for the development of clinical trial protocols.
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11
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Walter SD, Ishikawa H, Galetta KM, Sakai RE, Feller DJ, Henderson SB, Wilson JA, Maguire MG, Galetta SL, Frohman E, Calabresi PA, Schuman JS, Balcer LJ. Ganglion cell loss in relation to visual disability in multiple sclerosis. Ophthalmology 2012; 119:1250-7. [PMID: 22365058 DOI: 10.1016/j.ophtha.2011.11.032] [Citation(s) in RCA: 189] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 11/04/2011] [Accepted: 11/22/2011] [Indexed: 01/28/2023] Open
Abstract
PURPOSE We used high-resolution spectral-domain optical coherence tomography (SD-OCT) with retinal segmentation to determine how ganglion cell loss relates to history of acute optic neuritis (ON), retinal nerve fiber layer (RNFL) thinning, visual function, and vision-related quality of life (QOL) in multiple sclerosis (MS). DESIGN Cross-sectional study. PARTICIPANTS A convenience sample of patients with MS (n = 122; 239 eyes) and disease-free controls (n = 31; 61 eyes). Among MS eyes, 87 had a history of ON before enrollment. METHODS The SD-OCT images were captured using Macular Cube (200×200 or 512×128) and ONH Cube 200×200 protocols. Retinal layer segmentation was performed using algorithms established for glaucoma studies. Thicknesses of the ganglion cell layer/inner plexiform layer (GCL+IPL), RNFL, outer plexiform/inner nuclear layers (OPL+INL), and outer nuclear/photoreceptor layers (ONL+PRL) were measured and compared in MS versus control eyes and MS ON versus non-ON eyes. The relation between changes in macular thickness and visual disability was also examined. MAIN OUTCOME MEASURES The OCT measurements of GCL+IPL and RNFL thickness; high contrast visual acuity (VA); low-contrast letter acuity (LCLA) at 2.5% and 1.25% contrast; on the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and 10-Item Neuro-Ophthalmic Supplement composite score. RESULTS Macular RNFL and GCL+IPL were significantly decreased in MS versus control eyes (P<0.001 and P = 0.001) and in MS ON versus non-ON eyes (P<0.001 for both measures). Peripapillary RNFL, macular RNFL, GCL+IPL, and the combination of macular RNFL+GCL+IPL were significantly correlated with VA (P≤0.001), 2.5% LCLA (P<0.001), and 1.25% LCLA (P≤0.001). Among OCT measurements, reductions in GCL+IPL (P<0.001), macular RNFL (P = 0.006), and the combination (macular RNFL+GCL+IPL; P<0.001) were most strongly associated with lower (worse) NEI-VFQ-25 and 10-Item Supplement QOL scores; GCL+IPL thinning was significant even accounting for macular RNFL thickness (P = 0.03 for GCL+IPL, P = 0.39 for macular RNFL). CONCLUSIONS We demonstrated that GCL+IPL thinning is most significantly correlated with both visual function and vision-specific QOL in MS, and may serve as a useful structural marker of disease. Our findings parallel those of magnetic resonance imaging studies that show gray matter disease is a marker of neurologic disability in MS. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Scott D Walter
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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Smith AW, Das A, Guyton MK, Ray SK, Rohrer B, Banik NL. Calpain inhibition attenuates apoptosis of retinal ganglion cells in acute optic neuritis. Invest Ophthalmol Vis Sci 2011; 52:4935-41. [PMID: 21613375 DOI: 10.1167/iovs.10-7027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE Optic neuritis (ON), inflammation of the optic nerve, is strongly associated with the pathogenesis of multiple sclerosis (MS) and is initiated by the attack of autoreactive T cells against self-myelin antigens, resulting in demyelination, degeneration of retinal ganglion cells (RGCs), and cumulative visual impairment. METHODS Experimental autoimmune encephalomyelitis (EAE) was induced in Lewis rats on day 0, and animals received daily intraperitoneal injections of calpain inhibitor (calpeptin) or vehicle from day 1 until killed. Retinal cell death was analyzed by DNA fragmentation, and surviving ganglion cells were quantified after double labeling of retinal tissue with TUNEL and Brn3a. The expression of apoptotic and inflammatory proteins was determined by Western blotting. RESULTS It was demonstrated that calpain inhibition downregulates expression of proapoptotic proteins and the proinflammatory molecule nuclear factor-kappa B (NF-κB) in the retina of Lewis rats with acute EAE. Immunofluorescent labeling revealed that apoptotic cells in the RGC layer of vehicle-treated EAE animals were Brn3a positive, and a moderate dose of calpeptin dramatically reduced the frequency of apoptotic RGCs. CONCLUSIONS These results suggest that calpain inhibition might be a useful supplement to immunomodulatory therapies such as corticosteroids in ON, due to its neuroprotective effect on RGCs.
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Affiliation(s)
- Amena W Smith
- Departments of Neurosciences, Division of Neurology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Galetta KM, Calabresi PA, Frohman EM, Balcer LJ. Optical coherence tomography (OCT): imaging the visual pathway as a model for neurodegeneration. Neurotherapeutics 2011; 8:117-32. [PMID: 21274691 PMCID: PMC3075740 DOI: 10.1007/s13311-010-0005-1] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Axonal and neuronal degeneration are important features of multiple sclerosis (MS) and other neurologic disorders that affect the anterior visual pathway. Optical coherence tomography (OCT) is a non-invasive technique that allows imaging of the retinal nerve fiber layer (RNFL), a structure which is principally composed of ganglion cell axons that form the optic nerves, chiasm, and optic tracts. Since retinal axons are nonmyelinated until they penetrate the lamina cribrosa, the RNFL is an ideal structure (no other central nervous system tract has this unique arrangement) for visualizing the processes of neurodegeneration, neuroprotection and, potentially, even neuro-repair. OCT is capable of providing high-resolution reconstructions of retinal anatomy in a rapid and reproducible fashion and permits objective analysis of the RNFL (axons) as well as ganglion cells and other neurons in the macula. In a systematic OCT examination of multiple sclerosis (MS) patients, RNFL thickness and macular volumes are reduced when compared to disease-free controls. Conspicuously, these changes, which signify disorganization of retinal structural architecture, occur over time even in the absence of a history of acute demyelinating optic neuritis. RNFL axonal loss in MS is most severe in those eyes with a corresponding reduction in low-contrast letter acuity (a sensitive vision test involving the perception of gray letters on a white background) and in those patients who exhibit the greatest magnitude of brain atrophy, as measured by validated magnetic resonance imaging techniques. These unique structure-function correlations make the anterior visual pathway an ideal model for investigating the effects of standard and novel therapies that target axonal and neuronal degeneration. We provide an overview of the physics of OCT, its unique properties as a non-invasive imaging technique, and its potential applications toward understanding mechanisms of brain tissue injury in MS, other optic neuropathies, and neurologic disorders.
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Affiliation(s)
- Kristin M. Galetta
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania USA
| | - Peter A. Calabresi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Massachusetts USA
| | - Elliot M. Frohman
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas USA
| | - Laura J. Balcer
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania USA
- Department of Ophthalmology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania USA
- Department of Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania USA
- 3 E. Gates–Neurology, 3400 Spruce Street, Philadelphia, Pennsylvania 19104 USA
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Petzold A, de Boer JF, Schippling S, Vermersch P, Kardon R, Green A, Calabresi PA, Polman C. Optical coherence tomography in multiple sclerosis: a systematic review and meta-analysis. Lancet Neurol 2010; 9:921-32. [PMID: 20723847 DOI: 10.1016/s1474-4422(10)70168-x] [Citation(s) in RCA: 396] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Optical coherence tomography (OCT) is a new method that could aid analysis of neurodegeneration in multiple sclerosis (MS) by capturing thinning of the retinal nerve fibre layer (RNFL). Meta-analyses of data for time domain OCT show RNFL thinning of 20.38 microm (95% CI 17.91-22.86, n=2063, p<0.0001) after optic neuritis in MS, and of 7.08 microm (5.52-8.65, n=3154, p<0.0001) in MS without optic neuritis. The estimated RNFL thinning in patients with MS is greater than the extent expected in normal ageing, probably because of retrograde trans-synaptic degeneration and progressive loss of retinal ganglion cells, in addition to the more pronounced thinning caused by optic neuritis if present. RNFL thickness correlates with visual and neurological functioning as well as with paraclinical data. Developments that could improve understanding of the relation between structure and function in MS pathophysiology include spectral or Fourier domain OCT technology, polarisation-sensitive OCT, fluorescence labelling, structural assessment of action-potential propagation, and segmentation algorithms allowing quantitative assessment of retinal layers.
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Affiliation(s)
- Axel Petzold
- UCL Institute of Neurology/National Hospital for Neurology and Neurosurgery, Department of Neuroimmunology, Queen Square, London, UK.
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Talman LS, Bisker ER, Sackel DJ, Long DA, Galetta KM, Ratchford JN, Lile DJ, Farrell SK, Loguidice MJ, Remington G, Conger A, Frohman TC, Jacobs DA, Markowitz CE, Cutter GR, Ying GS, Dai Y, Maguire MG, Galetta SL, Frohman EM, Calabresi PA, Balcer LJ. Longitudinal study of vision and retinal nerve fiber layer thickness in multiple sclerosis. Ann Neurol 2010; 67:749-60. [PMID: 20517936 DOI: 10.1002/ana.22005] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Cross-sectional studies of optical coherence tomography (OCT) show that retinal nerve fiber layer (RNFL) thickness is reduced in multiple sclerosis (MS) and correlates with visual function. We determined how longitudinal changes in RNFL thickness relate to visual loss. We also examined patterns of RNFL thinning over time in MS eyes with and without a prior history of acute optic neuritis (ON). METHODS Patients underwent OCT measurement of RNFL thickness at baseline and at 6-month intervals during a mean follow-up of 18 months at 3 centers. Low-contrast letter acuity (2.5%, 1.25% contrast) and visual acuity (VA) were assessed. RESULTS Among 299 patients (593 eyes) with >or=6 months follow-up, eyes with visual loss showed greater RNFL thinning compared to eyes with stable vision (low-contrast acuity, 2.5%: p < 0.001; VA: p = 0.005). RNFL thinning increased over time, with average losses of 2.9microm at 2 to 3 years and 6.1microm at 3 to 4.5 years (p < 0.001 vs 0.5-1-year follow-up interval). These patterns were observed for eyes with or without prior history of ON. Proportions of eyes with RNFL loss greater than test-retest variability (>or=6.6microm) increased from 11% at 0 to 1 year to 44% at 3 to 4.5 years (p < 0.001). INTERPRETATION Progressive RNFL thinning occurs as a function of time in some patients with MS, even in the absence of ON, and is associated with clinically significant visual loss. These findings are consistent with subclinical axonal loss in the anterior visual pathway in MS, and support the use of OCT and low-contrast acuity as methods to evaluate the effectiveness of putative neuroprotection protocols.
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Affiliation(s)
- Lauren S Talman
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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