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Davis CQ, Hamilton R. Reference ranges for clinical electrophysiology of vision. Doc Ophthalmol 2021; 143:155-170. [PMID: 33880667 PMCID: PMC8494724 DOI: 10.1007/s10633-021-09831-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/16/2021] [Indexed: 11/28/2022]
Abstract
Introduction Establishing robust reference intervals for clinical procedures has received much attention from international clinical laboratories, with approved guidelines. Physiological measurement laboratories have given this topic less attention; however, most of the principles are transferable. Methods Herein, we summarise those principles and expand them to cover bilateral measurements and one-tailed reference intervals, which are common issues for those interpreting clinical visual electrophysiology tests such as electroretinograms (ERGs), visual evoked potentials (VEPs) and electrooculograms (EOGs). Results The gold standard process of establishing and defining reference intervals, which are adequately reliable, entails collecting data from a minimum of 120 suitable reference individuals for each partition (e.g. sex, age) and defining limits with nonparametric methods. Parametric techniques may be used under some conditions. A brief outline of methods for defining reference limits from patient data (indirect sampling) is given. Reference intervals established elsewhere, or with older protocols, can be transferred or verified with as few as 40 and 20 suitable reference individuals, respectively. Consideration is given to small numbers of reference subjects, interpretation of serial measurements using subject-based reference values, multidimensional reference regions and age-dependent reference values. Bilateral measurements, despite their correlation, can be used to improve reference intervals although additional care is required in computing the confidence in the reference interval or the reference interval itself when bilateral measurements are only available from some of subjects. Discussion Good quality reference limits minimise false-positive and false-negative results, thereby maximising the clinical utility and patient benefit. Quality indicators include using appropriately sized reference datasets with appropriate numerical handling for reporting; using subject-based reference limits where appropriate; and limiting tests for each patient to only those which are clinically indicated, independent and highly discriminating. Supplementary Information The online version contains supplementary material available at 10.1007/s10633-021-09831-1.
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Affiliation(s)
| | - Ruth Hamilton
- Department of Clinical Physics and Bioengineering, Royal Hospital for Children, NHS Greater Glasgow and Clyde, Glasgow, UK.
- College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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Large check size pattern reversal visual evoked potentials – Full and sectorial field stimulation in multiple sclerosis and controls. J Clin Neurosci 2020; 75:181-187. [DOI: 10.1016/j.jocn.2020.01.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/06/2020] [Indexed: 11/19/2022]
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Janáky M, Jánossy Á, Horváth G, Benedek G, Braunitzer G. VEP and PERG in patients with multiple sclerosis, with and without a history of optic neuritis. Doc Ophthalmol 2017; 134:185-193. [PMID: 28421377 DOI: 10.1007/s10633-017-9589-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/11/2017] [Indexed: 12/18/2022]
Abstract
PURPOSE Visual electrophysiology is routinely used to detect the visual complications of multiple sclerosis, but the analysis mostly focuses on visual evoked potential (VEP) and especially the P100 component. Our goal was to analyze the components and waveform alterations of VEPs and pattern electroretinograms (PERGs) in patients with multiple sclerosis (MS) with good vision. METHODS The main VEP and PERG components of 85 patients with MS were analyzed in two groups: 38 patients who had optic neuritis in their history (ON group) and 47 patients who had never had optic neuritis (MS group). The results were compared against a control group of 47 healthy subjects. RESULTS Both VEP and PERG alterations occurred in a greater number of patients than expected, and these alterations were not necessarily linked to ON in the history or a deterioration of visual acuity. CONCLUSIONS Both VEP and PERG can detect dysfunction in the visual system in MS, even if the patient has no subjective symptoms. Even if PERG is not routinely used in neuro-ophthalmology, the results suggest that PERG assessment may provide useful information describing the retinal defect in MS.
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Affiliation(s)
- M Janáky
- Department of Ophthalmology, Faculty of Medicine, University of Szeged, Korányi fasor 10-11, Szeged, 6720, Hungary
| | - Á Jánossy
- Department of Ophthalmology, Faculty of Medicine, University of Szeged, Korányi fasor 10-11, Szeged, 6720, Hungary
| | - G Horváth
- Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, Szeged, 6720, Hungary
| | - G Benedek
- Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, Szeged, 6720, Hungary
| | - G Braunitzer
- Laboratory for Perception & Cognition and Clinical Neuroscience, Nyírő Gyula Hospital, Lehel utca 59, Budapest, 1135, Hungary.
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Brecelj J. Visual electrophysiology in the clinical evaluation of optic neuritis, chiasmal tumours, achiasmia, and ocular albinism: an overview. Doc Ophthalmol 2014; 129:71-84. [PMID: 24962442 DOI: 10.1007/s10633-014-9448-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 06/09/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND AND METHODS In routine clinical evaluation of optic neuritis and chiasmal tumours, pattern electroretinography and visual evoked potentials (VEPs) to pattern-reversal stimulation are useful examinations. Similarly, in achiasmia and ocular albinism, VEPs to flash and pattern-onset stimulation provide relevant information. RESULTS The role of visual electrophysiology in these diseases is to assess potential dysfunction of the visual pathway: (a) at the acute stage of optic neuritis, to determine the magnitude of conduction block of the optic nerve fibres; (b) at the clinical recovery stage of optic neuritis, to determine optic nerve conduction delay due to demyelination, and to follow possible remyelination; (c) at the recovery of optic neuritis when visual acuity does not normalise, to define loss of optic nerve fibres and retrograde degeneration of retinal ganglion cells; (d) in tumours at the chiasm, to detect abnormal conduction along the crossed and/or uncrossed fibres; and (e) in achiasmia or albinism, which are both congenital disorders associated with nystagmus, to detect achiasmia and absence of or reduced optic nerve fibre decussation at the chiasm, or to detect ocular albinism and excess of optic nerve fibre decussation at the chiasm. In optic neuritis, two recent examinations have been used to detect retrograde axonal degeneration: photopic negative response of the electroretinogram, to assess dysfunction of ganglion cell axons; and optic coherence tomography, to measure thinning of the retinal nerve fibre layer. In optic neuritis, multifocal VEPs provide a promising clinical examination, because this can show areas that are associated with normal or abnormal optic nerve fibre function. CONCLUSIONS Visual electrophysiology defines function of the visual pathway and is relevant: (1) in optic neuritis, when visual acuity does not recover well; (2) in tumours of the chiasm with normal visual fields, as in paediatric patients who cannot adequately perform perimetry; and (3) in children with congenital nystagmus and suspected achiasmia or ocular albinism.
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Affiliation(s)
- Jelka Brecelj
- Unit for Visual Electrophysiology, Eye Hospital, University Medical Centre, Grablovičeva 46, 1000, Ljubljana, Slovenia,
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Stothart G, Tales A, Hedge C, Kazanina N. Double peaked P1 visual evoked potentials in healthy ageing. Clin Neurophysiol 2013; 125:1471-8. [PMID: 24370492 DOI: 10.1016/j.clinph.2013.11.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 10/30/2013] [Accepted: 11/15/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVES To robustly examine the prevalence of the double peaked P1 visual evoked potential in healthy younger and older adult populations. METHODS The evoked potentials and spectral power changes to simple visual stimuli of 26 healthy younger (M=20.0 y) and 26 healthy older adults (M=76.0 y) were examined. RESULTS Group and individual analyses showed a clear effect of age on P1 morphology and amplitude. Older adults showed significantly lower P1 amplitude and 44% of older adults showed a double peaked P1 compared to 12% of younger adults. Double peaked P1 responses were associated with an increase in spectral power in the gamma range. CONCLUSIONS The double peaked P1 may be more prevalent in older adults than previously demonstrated and may represent a de-synchronisation of the cortical sources of the visual P1 in healthy ageing. Increased power in post stimulus gamma in the double peak group may be indicative of compensatory neural processing. SIGNIFICANCE Clinically the prevalence of the double peaked P1 may have been underestimated, and its reflectance of demyelinating disease overestimated. Experimentally the results suggest that any investigation of visual processing in older adults must control for early changes in P1 morphology.
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Affiliation(s)
- G Stothart
- School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK.
| | - A Tales
- School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK
| | - C Hedge
- School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK
| | - N Kazanina
- School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK
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Mellow TB, Liasis A, Lyons R, Thompson D. When do asymmetrical full-field pattern reversal visual evoked potentials indicate visual pathway dysfunction in children? Doc Ophthalmol 2010; 122:9-18. [PMID: 21046194 DOI: 10.1007/s10633-010-9250-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2010] [Accepted: 10/11/2010] [Indexed: 11/28/2022]
Abstract
Our study aimed to find out the association between full-field pattern reversal visual evoked potential (pVEP) transoccipital asymmetries and half-field pVEP transoccipital distributions in children. Over a six-month period, 46 patients (mean age: 9 years 9 months) had both monocular full-field and half-field pVEPs to test checks subtending 50 min of arc in a 35 degree full-field and 0-17.5 degree lateral half-field. Silver-silver chloride electrodes placed at Oz, O1 and O2 were referred to Fz. Monocular full-field data were categorised according to the degree of transoccipital asymmetry. Half-field data were measured and summated to see whether they explained any full-field asymmetry. In this cohort of 46 patients, eight (17%) patients had symmetrically distributed monocular full-field pVEPs for each eye. Four of these patients had normal half-field pVEP distributions for each eye, but the other four showed a half-field deficit in one or both eyes. Of the 38 patients with asymmetrically distributed full-field pVEPs in at least one eye, 17 (44%) patients showed a half-field deficit, 20 (53%) showed responsive, but symmetrically distributed half-field responses, and one patient (3%) showed typical half-field distributions. Half-field pVEPs can help explain full-field asymmetries and should be attempted in any child able to co-operate with testing and in whom visual pathway dysfunction is suspected.
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Affiliation(s)
- Tessa B Mellow
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK
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Strucl M, Brecelj J, Hawlina M. Visual evoked potential abnormalities in compressive chiasmal lesions: the relevance of central visual field defects. Neuroophthalmology 2009. [DOI: 10.3109/01658109709044650] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Janáky M, Pálffy A, Horváth G, Tuboly G, Benedek G. Pattern-reversal electroretinograms and visual evoked potentials in retinitis pigmentosa. Doc Ophthalmol 2007; 117:27-36. [PMID: 18034272 DOI: 10.1007/s10633-007-9099-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Accepted: 10/31/2007] [Indexed: 11/29/2022]
Affiliation(s)
- Márta Janáky
- Department of Ophthalmology, Faculty of Medicine, University of Szeged, Korányi rkpt. 10-11, Pf: 427, 6720 Szeged, Hungary.
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Rousseff RT, Tzvetanov P, Rousseva MA. The bifid visual evoked potential-normal variant or a sign of demyelination? Clin Neurol Neurosurg 2005; 107:113-6. [PMID: 15708225 DOI: 10.1016/j.clineuro.2004.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Revised: 05/23/2004] [Accepted: 05/24/2004] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To prospectively evaluate the diagnostic significance of bifid VEP at initial presentation. MATERIALS AND METHODS A hundred and sixteen patients (46 males and 70 females, age 15-54, mean 28.8), with a clinical suspicion of multiple sclerosis (MS), underwent pattern-shift VEP investigation between 1992 and 1998. They were further followed by clinical, CSF, MRI means for at least 5 years (mean 7.2). Twenty-six patients remained healthy, while 90 developed demyelinating disease (in 71 MS and in 19 optic neuritis was the final diagnosis). Fifty healthy persons (20 males aged 18-51, mean 28.8 and 30 females aged 18-48, mean 26.2) represented the control group. The number of persons with bifid VEP in each group are analyzed. RESULTS In the controls one out of 50 exhibited bifid VEP configuration. Of 26 patients with unconfirmed suspicion for MS again one had such responses. Bifid VEP were significantly more frequent in patients with demyelinative pathology (nine out of 90, 10.0%, P (chi-squared) < 0.01). CONCLUSIONS Bifid VEP is rarely observed in healthy persons. Its presence should suggest the possibility of demyelinating disease and prompt further investigation and follow-up.
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Affiliation(s)
- Rossen T Rousseff
- Department of Neurology, Medical University Hospital, G Kochev 8A, 5800 Pleven, Bulgaria.
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Brecelj J, Strucl M, Zidar I, Tekavcic-Pompe M. Pattern ERG and VEP maturation in schoolchildren. Clin Neurophysiol 2002; 113:1764-70. [PMID: 12417229 DOI: 10.1016/s1388-2457(02)00254-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The maturation of the visual system has been studied with pattern electroretinograms (PERG) and pattern visual evoked potentials (PVEP) mostly in children under the age of 6 years. To address the question of maturation of the visual system in childhood and adolescence we investigated age-dependent PERG and PVEP changes in children aged 7-18 years. METHODS PERG were recorded with skin electrodes attached to the lower eyelid, and PVEP were recorded with 5 electrodes. Visual stimuli, consisting of pattern-reversal 50' checks to full-field and to half-field stimulation, were applied to obtain macular (N70, P100, N145) and paramacular waves (P80, N105, N135). RESULTS We found an age-dependent decrease (linear regression P<0.05) of PERG P50 amplitude and full-field PVEP P100 latency to monocular right and left eye stimulation, indicating central retinal and postretinal changes. In addition, waveform changes were found in responses to half-field stimulation. The paramacular wave N105 was typically enhanced in younger schoolchildren and diminished with age. The age-dependent decrease (linear regression P<0.01) of paramacular N105 amplitude indicated the increasing predominance of the macular structures of the visual system. CONCLUSIONS Our findings suggest that central retinal and postretinal electrophysiological maturation persists throughout childhood. Age-dependent PVEP changes seem to correlate with the morphological and metabolic findings that maturation of the visual cortex continues until puberty and even later.
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Affiliation(s)
- Jelka Brecelj
- Eye Clinic, University Medical Centre, Zaloska c. 29a, 1525 Ljubljana, Slovenia.
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Brecelj J. A VEP study of the visual pathway function in compressive lesions of the optic chiasm. Full-field versus half-field stimulation. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1992; 84:209-18. [PMID: 1375880 DOI: 10.1016/0168-5597(92)90002-s] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Changes of the pattern reversal visual evoked potentials (VEPs) to half- and full-field stimulation in 50 patients with compressive lesions of the optic chiasm are presented. Temporal half-field stimulation yielded abnormal responses in 85% of the eyes, showing non-recordable P100 in 50% of eyes, while in 35% the P100 was significantly attenuated or delayed. With nasal half-field the percentage of all detectable abnormalities was lower (36% of the eyes). Full-field stimulation revealed VEP abnormalities in 74% of eyes and therefore proved less sensitive than the half-field stimulation. This study adds new evidence that half-field stimulation can be an important adjunct for assessing the function of the optic chiasm.
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Affiliation(s)
- J Brecelj
- University Institute of Clinical Neurophysiology, University Medical Centre Ljubljana, Slovenia
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Brecelj J. Visual evoked potentials and the localization of visual pathway lesions. SPEKTRUM DER AUGENHEILKUNDE 1991. [DOI: 10.1007/bf03163834] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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