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Calcagni A, Neveu MM, Jurkute N, Robson AG. Electrodiagnostic tests of the visual pathway and applications in neuro-ophthalmology. Eye (Lond) 2024:10.1038/s41433-024-03154-6. [PMID: 38862643 DOI: 10.1038/s41433-024-03154-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/16/2024] [Accepted: 05/22/2024] [Indexed: 06/13/2024] Open
Abstract
This article describes the main visual electrodiagnostic tests relevant to neuro-ophthalmology practice, including the visual evoked potential (VEP), and the full-field, pattern and multifocal electroretinograms (ffERG; PERG; mfERG). The principles of electrophysiological interpretation are illustrated with reference to acquired and inherited optic neuropathies, and retinal disorders that may masquerade as optic neuropathy, including ffERG and PERG findings in cone and macular dystrophies, paraneoplastic and vascular retinopathies. Complementary VEP and PERG recordings are illustrated in demyelinating, ischaemic, nutritional (B12), and toxic (mercury, cobalt, and ethambutol-related) optic neuropathies and inherited disorders affecting mitochondrial function such as Leber hereditary optic neuropathy and dominant optic atrophy. The value of comprehensive electrophysiological phenotyping in syndromic diseases is highlighted in cases of SSBP1-related disease and ROSAH (Retinal dystrophy, Optic nerve oedema, Splenomegaly, Anhidrosis and Headache). The review highlights the value of different electrophysiological techniques, for the purposes of differential diagnosis and objective functional phenotyping.
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Affiliation(s)
- Antonio Calcagni
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
- Institute of Ophthalmology, University College London, London, UK
| | - Magella M Neveu
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
- Institute of Ophthalmology, University College London, London, UK
| | - Neringa Jurkute
- Institute of Ophthalmology, University College London, London, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK
- Department of Neuro-ophthalmology, Moorfields Eye Hospital, London, UK
- Department of Neuro-ophthalmology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK
| | - Anthony G Robson
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK.
- Institute of Ophthalmology, University College London, London, UK.
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK.
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Morny EKA, Haldina J, Heinrich SP. Simulating the Effects of Partial Neural Conduction Delays in the Visual Evoked Potential. Transl Vis Sci Technol 2024; 13:18. [PMID: 38386346 PMCID: PMC10896232 DOI: 10.1167/tvst.13.2.18] [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: 07/24/2023] [Accepted: 12/26/2023] [Indexed: 02/23/2024] Open
Abstract
Purpose The purpose of this study was to understand the double peaks or broadening of P100 observed in some cases of optic neuritis by inducing conduction delays in healthy eyes through stimulus luminance manipulation in analogy to the perceptual Pulfrich effect. Methods Checkerboard pattern reversal visual evoked potentials (VEPs) with check sizes of 0.8 degrees, 0.4 degrees, and 0.2 degrees were recorded in healthy participants using two experiment variants. Variant (1) involved binocular stimulation with inter-ocular luminance difference achieved by a 1.8 neutral density (ND) filter, along with monocular control conditions. Variant (2) included monocular stimulation with hemifields having a luminance difference (half of monitor with ND filter), along with single-hemifield control conditions. In both variants, VEP curves under mixed stimulation were compared to synthesized VEPs computed from offline summation of curves from the relevant control conditions, followed by assessing P100 characteristics. Results Despite considerable variability between participants, the binocular variant demonstrated marked differences between VEPs from mixed recordings and synthesized curves, whereas in the hemifield variant, agreement was strong. The anticipated double peak or broadened deflection pattern was observed to varying extents in participants, often contingent on check size, with nominal peak time frequently failing to indicate partial conduction delays. Conclusions The present findings corroborate the hypothesis that nominal peak time does not always reflect conduction delays if only a subset of fiber bundles is affected. Peak shape might provide additional diagnostic evidence of a partial conduction delay. Translational Relevance Enhancing the understanding of VEP waveform changes associated with partial conduction delays could offer diagnostic insights for optic neuritis.
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Affiliation(s)
- Enyam K. A. Morny
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Optometry and Vision Science, University of Cape Coast, Cape Coast, Ghana
| | - Julia Haldina
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sven P. Heinrich
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Hof S, van Rijn LJ, Uitdehaag BMJ, Nij Bijvank JA, Petzold A. Measuring and predicting the effect of remyelinating therapy in multiple sclerosis: a randomised controlled trial protocol (RESTORE). BMJ Open 2024; 14:e076651. [PMID: 38296293 PMCID: PMC10828865 DOI: 10.1136/bmjopen-2023-076651] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
INTRODUCTION Remyelination failure hampers symptomatic recovery in multiple sclerosis (MS), underlining the importance of developing remyelinating therapies. Optic neuritis is currently the most established method of measuring remyelination in MS trials. Complementary more generalisable methods of measuring remyelination are required to confirm treatment efficacy. Measuring internuclear ophthalmoplegia (INO) with infrared oculography provides such a method. Moreover, this method can be expanded with a test for selecting likely treatment responders by using fampridine. The aim of this trial is to investigate the (long-term) remyelinating effects of clemastine fumarate in patients with MS and INO and to evaluate if treatment response can be predicted using fampridine. METHODS AND ANALYSIS RESTORE is a single-centre double-blind randomised placebo-controlled trial of clemastine fumarate versus placebo. Prior to clemastine treatment improvement in oculographic features of INO after a single 10 mg dose of fampridine is measured in all participants and used to predict the treatment response to clemastine. Eighty individuals with MS and INO will be 1:1 randomised to 4 mg of clemastine fumarate two times a day for 6 months or equivalent placebo. Our primary outcome is improvement in the Versional Dysconjugacy Index-area under the curve, measured by infrared oculography after 6 months of treatment. Participants are assessed for persistent treatment effects 6, 18 and 30 months after end of treatment. Secondary outcome measures include other oculography parameters including double-step saccades, retinal imaging, visual acuities, physical disability, cognition and patient-reported outcomes. ETHICS AND DISSEMINATION Clemastine is a registered and very well-established drug with well-known safety and side effects. The protocol was approved by the medical ethical committee of the Amsterdam UMC, location VUMC and the Dutch Central Committee on Research Involving Human Subject. Written informed consent is obtained from all participants. The results will be published in peer-reviewed medical scientific journals. TRIAL REGISTRATION NUMBER EudraCT: 2021-003677-66, ClinicalTrials.gov: NCT05338450.
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Affiliation(s)
- Sam Hof
- MS Center and Neuro-ophthalmology Expertise Center Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, Noord-Holland, The Netherlands
| | - Laurentius J van Rijn
- Ophthalmology, Amsterdam UMC Location VUmc, Amsterdam, Noord-Holland, The Netherlands
- Opthalmology, Onze Lieve Vrouwe Hospital, Amsterdam, Noord-Holland, The Netherlands
| | - Bernard M J Uitdehaag
- MS Center and Neuro-ophthalmology Expertise Center Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, Noord-Holland, The Netherlands
| | - Jenny A Nij Bijvank
- MS Center and Neuro-ophthalmology Expertise Center Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, Noord-Holland, The Netherlands
- Ophthalmology, Amsterdam UMC Location VUmc, Amsterdam, Noord-Holland, The Netherlands
| | - Axel Petzold
- MS Center and Neuro-ophthalmology Expertise Center Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, Noord-Holland, The Netherlands
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Ganapathy Subramanian R, Zivadinov R, Bergsland N, Dwyer MG, Weinstock-Guttman B, Jakimovski D. Multiple sclerosis optic neuritis and trans-synaptic pathology on cortical thinning in people with multiple sclerosis. J Neurol 2023:10.1007/s00415-023-11709-y. [PMID: 37067590 DOI: 10.1007/s00415-023-11709-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/31/2023] [Accepted: 04/05/2023] [Indexed: 04/18/2023]
Abstract
BACKGROUND The multi-order visual system represents an excellent testing site regarding the process of trans-synaptic degeneration. The presence and extent of global versus trans-synaptic neurodegeneration in people with multiple sclerosis (pwMS) is not clear. OBJECTIVE To explore cross-sectional and longitudinal relationships between retinal, thalamic and cortical changes in pwMS with and without MS-related optic neuritis (pwMSON and pwoMSON) using MRI and optical coherence tomography (OCT). METHODS 162 pwMS and 47 healthy controls (HCs) underwent OCT and brain MRI at baseline and 5.5-years follow-up. Peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell inner plexiform layer (mGCIPL) thicknesses were determined. Global volume measures of brain parenchymal volume (BPV)/percent brain volume change (PBVC), thalamic volume and T2-lesion volume (LV) were derived using standard analysis protocols. Regional cortical thickness was determined using FreeSurfer. Cross-sectional and longitudinal relationship between the retinal measures, thalamic volume and cortical thickness were assessed using age, BPV/PBVC and T2-LV adjusted correlations and regressions. RESULTS After age, BPV and T2-LV adjustment, the thalamic volume explained additional variance in the thickness of pericalcarine (R2 increase of 0.066, standardized β = 0.299, p = 0.039) and lateral occipital (R2 increase of 0.024, standardized β = 0.299, p = 0.039) gyrii in pwMSON. In pwoMSON, the thalamic volume was a significant predictor only of control (frontal) regions of pars opercularis. There was no relationship between thalamic atrophy and cortical thinning over the follow-up in both pwMS with and without MSON. While numerically lower in the pwMSON group, the inter-eye difference was not able to predict the presence of MSON. CONCLUSIONS MSON can induce a measurable amount of trans-synaptic pathology on second-order cortical regions.
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Affiliation(s)
- Ranjani Ganapathy Subramanian
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 100 High Street, Buffalo, NY, 14203, USA
| | - Robert Zivadinov
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 100 High Street, Buffalo, NY, 14203, USA
- Center for Biomedical Imaging at the Clinical Translational Science Institute, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Niels Bergsland
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 100 High Street, Buffalo, NY, 14203, USA
- IRCCS, Fondazione Don Carlo Gnocchi, Milan, Italy
| | - Michael G Dwyer
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 100 High Street, Buffalo, NY, 14203, USA
| | - Bianca Weinstock-Guttman
- Department of Neurology, Jacobs Comprehensive MS Treatment and Research Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Dejan Jakimovski
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 100 High Street, Buffalo, NY, 14203, USA.
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