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Mavilio A, Sisto D, Dammacco R, Durante G, Alessio G. Retrograde Optic Nerve Degeneration in Pituitary Adenoma: A Study with RE-PERG. Clin Ophthalmol 2022; 16:4135-4144. [DOI: 10.2147/opth.s384525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/29/2022] [Indexed: 12/15/2022] Open
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Marmoy OR, Viswanathan S. Clinical electrophysiology of the optic nerve and retinal ganglion cells. Eye (Lond) 2021; 35:2386-2405. [PMID: 34117382 PMCID: PMC8377055 DOI: 10.1038/s41433-021-01614-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/11/2021] [Accepted: 05/19/2021] [Indexed: 12/28/2022] Open
Abstract
Clinical electrophysiological assessment of optic nerve and retinal ganglion cell function can be performed using the Pattern Electroretinogram (PERG), Visual Evoked Potential (VEP) and the Photopic Negative Response (PhNR) amongst other more specialised techniques. In this review, we describe these electrophysiological techniques and their application in diseases affecting the optic nerve and retinal ganglion cells with the exception of glaucoma. The disease groups discussed include hereditary, compressive, toxic/nutritional, traumatic, vascular, inflammatory and intracranial causes for optic nerve or retinal ganglion cell dysfunction. The benefits of objective, electrophysiological measurement of the retinal ganglion cells and optic nerve are discussed, as are their applications in clinical diagnosis of disease, determining prognosis, monitoring progression and response to novel therapies.
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Affiliation(s)
- Oliver R Marmoy
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK.
- UCL-GOS Institute for Child Health, University College London, London, UK.
- Manchester Metropolitan University, Manchester, UK.
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Handley SE, Šuštar M, Tekavčič Pompe M. What can visual electrophysiology tell about possible visual-field defects in paediatric patients. Eye (Lond) 2021; 35:2354-2373. [PMID: 34272512 PMCID: PMC8377065 DOI: 10.1038/s41433-021-01680-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/21/2021] [Accepted: 06/29/2021] [Indexed: 02/06/2023] Open
Abstract
Recognising a potential visual-field (VF) defect in paediatric patients might be challenging, especially in children before the age of 5 years and those with developmental delay or intellectual disability. Visual electrophysiological testing is an objective and non-invasive technique for evaluation of visual function in paediatric patients, which can characterise the location of dysfunction and differentiate between disorders of the retina, optic nerve and visual pathway. The recording of electroretinography (ERG) and visual-evoked potentials (VEP) is possible from early days of life and requires no subjective input from the patient. As the origins of ERG and VEP tests are known, the pattern of electrophysiological changes can provide information about the VF of a child unable to perform accurate perimetry. This review summarises previously published electrophysiological findings in several common types of VF defects that can be found in paediatric patients (generalised VF defect, peripheral VF loss, central scotoma, bi-temporal hemianopia, altitudinal VF defect, quadrantanopia and homonymous hemianopia). It also shares experience on using electrophysiological testing as additional functional evidence to other tests in the clinical challenge of diagnosing or excluding VF defects in complex paediatric patients. Each type of VF defect is illustrated with one or two clinical cases.
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Affiliation(s)
- Siân E. Handley
- grid.83440.3b0000000121901201UCL Great Ormond Street Institute of Child Health, London, UK ,grid.424537.30000 0004 5902 9895Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS foundation trust, London, UK
| | - Maja Šuštar
- grid.29524.380000 0004 0571 7705Unit for Visual Electrophysiology and Paediatric Ophthalmology Department, Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Manca Tekavčič Pompe
- grid.29524.380000 0004 0571 7705Unit for Visual Electrophysiology and Paediatric Ophthalmology Department, Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
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Dotto PDF, Berezovsky A, Sacai PY, Rocha DM, Fernandes AG, Salomão SR. Visual function assessed by visually evoked potentials in adults with orbital and other primary intracranial tumors. Eur J Ophthalmol 2020; 31:1351-1360. [PMID: 32468859 DOI: 10.1177/1120672120925643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE The purpose of this study was to assess visual function by visually evoked potentials in adults with orbital and other primary brain tumors affecting the optic pathway. METHODS In this retrospective case-control series, patients with orbital (intraconal and extraconal) or midline/chiasmatic tumors were included. Visually evoked potentials using pattern-reversal visually evoked potential and flash visually evoked potential stimuli were performed according to the international standards. Outcome measures were visually evoked potential parameters of amplitude (µV) and peak times (ms) measured both for the P100 component (pattern-reversal visually evoked potentials) and the N2P2 complex (flash visually evoked potential). Individual results were also compared with gender-based normative values. RESULTS A group of 21 adult patients (17 females) and age- and sex-matched controls were evaluated. Tumor location was intraconal (6 meningiomas, 3 hemangiomas, 1 glioma), extraconal (6 meningiomas), and midline (3 pituitary adenomas, 2 hypothalamic/chiasmatic low-grade gliomas). Abnormal fundus (76%), abnormal pupillary reflexes (71%), reduced visual acuity (62%), strabismus (48%), and proptosis (38%) were present. Visually evoked potential abnormalities were found in at least one eye of all cases. Affected eyes had significantly reduced amplitudes and prolonged peak times for pattern-reversal visually evoked potentials (p < .001) and significantly reduced amplitudes for flash visually evoked potential (p < .001). In unilateral orbital tumors, abnormally prolonged pattern-reversal visually evoked potential peak times were also detected in some contralateral eyes (n = 6/16). CONCLUSION Visually evoked potential abnormalities were found in all adult patients with orbital and other intracranial primary tumors, even in eyes with normal exam and good visual acuity. Visually evoked potential can be used as a non-invasive ancillary test to characterize and monitor visual function in subjects with these neoplastic lesions.
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Affiliation(s)
- Patrícia de Freitas Dotto
- Laboratório de Eletrofisiologia Visual Clínica, Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil
| | - Adriana Berezovsky
- Laboratório de Eletrofisiologia Visual Clínica, Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil
| | - Paula Yuri Sacai
- Laboratório de Eletrofisiologia Visual Clínica, Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil
| | - Daniel Martins Rocha
- Laboratório de Eletrofisiologia Visual Clínica, Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil
| | - Arthur Gustavo Fernandes
- Laboratório de Eletrofisiologia Visual Clínica, Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil
| | - Solange Rios Salomão
- Laboratório de Eletrofisiologia Visual Clínica, Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil
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Visual loss and recovery in chiasmal compression. Prog Retin Eye Res 2019; 73:100765. [DOI: 10.1016/j.preteyeres.2019.06.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/05/2019] [Accepted: 06/12/2019] [Indexed: 12/18/2022]
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Visual function assessed by visually evoked potentials in optic pathway low-grade gliomas with and without neurofibromatosis type 1. Doc Ophthalmol 2018; 136:177-189. [PMID: 29766345 DOI: 10.1007/s10633-018-9635-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/08/2018] [Indexed: 10/16/2022]
Abstract
PURPOSE To investigate the contribution of full-field transient pattern-reversal visually evoked potentials (PRVEP) on cross-sectional evaluations of visual function in patients with and without neurofibromatosis type 1 (NF1) affected by optic pathway low-grade gliomas (OPLGG). METHODS Participants were children and adolescents referred for visual function evaluation and receiving treatment for OPLGG, linked (NF1-OPLGG) or not to NF1 (Non-NF1-OPLGG). An age-adjusted control group was included for comparison. Monocular full-field PRVEPs were recorded from each eye in accordance with ISCEV standards. Parameters of peak-to-peak P100 amplitude (µV) and P100 peak time (ms) were measured. Cutoff normative values obtained from controls for 15' and 60' check sizes were ≥ 9.0 µV for N75-P100 amplitude and ≤ 103.0 ms for P100 peak time. The association of age, gender, tumor resection and NF1 with P100 amplitude reduction and P100 peak time delay was explored by Firth logistic regression modeling. RESULTS Participants were 30 patients (15 males, 60% Non-NF1) with ages from 3.6 to 19.9 years (mean ± SD = 9.2 ± 3.8 years; median = 8.4 years) and 19 controls (12 males) with ages from 3.7 to 19.9 years (mean ± SD = 10.4 ± 4.9 years; median = 9.5 years). Overall, 68% of tested eyes presented reduced P100 amplitudes for both check sizes (46% in the NF-1 and 83% in the Non-NF1) and delayed P100 for both check sizes (38% in NF1 and 89% in Non-NF1). Absence of NF1 adjusted for age, gender and tumor resection was significantly associated with marginally reduced P100 amplitude for 15' checks [odds ratio (OR): 6.26; 95% confidence interval (CI) = 0.96-40.94; p = 0.055]. CONCLUSIONS Full-field PRVEP on cross-sectional evaluations contributed to detect visual dysfunction in two-thirds of patients with OPLGG by highlighting subclinical evidence of visual loss. Abnormalities were more frequent and more severe in OPLGG not linked to NF1 than in NF1-OPLGG; however, there was a difference in surgical management between these groups. PRVEP parameters may provide reliable evidence of visual pathway involvement in OPLGG, helping to hasten treatment before optic atrophy is detected.
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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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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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Park SY, Park SH, Ha SJ, Park SH. Correlation of OCT and Hemifield Pattern VEP in Hemianopia. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2008. [DOI: 10.3341/jkos.2008.49.11.1819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sung Yong Park
- Department of Ophthalmology, Soonchunhyang University School of Medicine, Seoul, Korea
| | - Sang Hyouk Park
- Department of Ophthalmology, Soonchunhyang University School of Medicine, Seoul, Korea
| | - Seung Joo Ha
- Department of Ophthalmology, Soonchunhyang University School of Medicine, Seoul, Korea
| | - Song Hee Park
- Department of Ophthalmology, Soonchunhyang University School of Medicine, Seoul, Korea
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Brecelj J, Stirn-Kranjc B, Pecaric-Meglic N, Skrbec M. VEP asymmetry with ophthalmological and MRI findings in two achiasmatic children. Doc Ophthalmol 2007; 114:53-65. [PMID: 17221217 DOI: 10.1007/s10633-006-9037-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Indexed: 10/23/2022]
Abstract
Achiasmia is a rarely diagnosed visual pathway maldevelopment where all or the majority of nasal retinal fibres fail to decussate at the optic chiasm. It has been identified by neuroimaging and also by visual evoked potential (VEP) asymmetry. VEP asymmetry has not been defined consistently in previous studies. The aim was to study VEP asymmetry to flash stimulation in two children with maldevelopment of the optic chiasm in comparison to control children. Both children had congenital nystagmus, optic nerve hypoplasia with a bilateral small double ring, bitemporal visual field defect and normal colour vision. In child 1 visual acuity in both eyes was 0.1, in child 2 it was 0.2. MRI showed reduced chiasmal size in child 1, while in child 2 it was combined with other midline abnormalities. VEP to monocular flash stimulation showed in both children distinctive occipital distribution, which was not observed in control children. The N2 wave was distributed asymmetrically over the ipsilateral hemisphere to the stimulated eye, while the P2 wave was distributed over both hemispheres. The P2 wave was however better defined over the ipsilateral hemisphere. Flash VEP occipital distribution remained similar in child 1, who was followed from 10 months to 9 years. These cases of achiasmia demonstrate a distinctive VEP asymmetry in the distribution of the flash VEP N2 wave, as well as the expected structural defect determined by neuroimaging.
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Affiliation(s)
- Jelka Brecelj
- Unit for Visual Electrophysiology, Eye Clinic, University Medical Centre, Ljubljana, Slovenia.
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Hidajat RR, McLay JL, Goode DH, Hidayat JR. The value of VEP in the diagnosis and post-operative monitoring of meningioma. Doc Ophthalmol 2006; 113:165-9. [PMID: 17019611 DOI: 10.1007/s10633-006-9025-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Indexed: 10/24/2022]
Abstract
Meningiomas are the most frequently reported primary intracranial neoplasms. At first they usually cause unilateral visual loss but eventually result in a bilateral loss of vision. Depending upon the size and location of the tumour, the ocular signs and symptoms of meningiomas may include visual field abnormalities, optic atrophy, papilledema, diplopia and proptosis. This case report highlights the value of visual evoked potentials (VEP) in a patient with unexplained bilateral optic atrophy and a progressive loss of vision over 2 years. As a result of a delayed response in the VEP recorded from the right eye, a compressive lesion of the optic nerve was suspected. That prompted the referring ophthalmologist to request a MRI scan which led to the diagnosis of meningioma. Following the subtotal removal of the suprasellar meningioma, the remaining vision in the right eye improved and the latency of the VEP returned to the normal range. However, the VEP from the blind eye (left) did not show any measurable response either pre- or postoperatively. Experience with this patient suggests that early recognition of optic nerve compression is vital to an optimal outcome and the VEP technique, which is much more cost-effective than MRI, is clinically useful for detecting such compressive lesions.
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Affiliation(s)
- Rudy R Hidajat
- Department of Ophthalmology, Christchurch Hospital, Private Bag 4710, Christchurch, New Zealand.
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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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Braun C, Weber J, Schiefer U, Skalej M, Dietrich T. Hyperexcitatory activity in visual cortex in homonymous hemianopia after stroke. Clin Neurophysiol 2001; 112:336-43. [PMID: 11165539 DOI: 10.1016/s1388-2457(00)00508-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES Damage to and destruction of neural afferents result in a disruption of sensory input, which causes reduced activity in the corresponding cortical areas. Conversely, there is also evidence that lesions in the sensory pathway induce changes in the intracortical connectivity resulting in augmented cortical activity due to disinhibition. As disinhibition is assumed to be involved in the reconfiguration of neural networks, its appearance after brain lesions might be relevant for the restitution of impaired brain functions. METHODS The effects of lesions in the visual pathway on the activity in visual cortex were studied using magnetoencephalography. In order to compare the neural activity affected by the lesion with the activity associated with intact visual processing, only patients with unilateral, post-chiasmatic lesions resulting in homonymous hemianopia were examined. RESULTS Stimulation within the scotoma resulted in reduced magnetic activity compared to the stimulation of the intact hemifield. Increased activity was observed when the border region of the scotoma was stimulated. CONCLUSIONS It is concluded that the magnetic hyperactivity reflects cortical disinhibition induced by lesions in the visual system. Furthermore, the possible role of cortical disinhibition as a basis for cortical reorganization and as a precondition for the recovery of impaired visual functions is discussed.
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Affiliation(s)
- C Braun
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Otfried-Müller-Strasse 47, 72076, Tübingen, Germany.
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Parmar DN, Sofat A, Bowman R, Bartlett JR, Holder GE. Visual prognostic value of the pattern electroretinogram in chiasmal compression. Br J Ophthalmol 2000; 84:1024-6. [PMID: 10966958 PMCID: PMC1723665 DOI: 10.1136/bjo.84.9.1024] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIMS The visual loss associated with compression of the optic chiasm by pituitary tumours may be transient or permanent, possibly related to the extent of irreversible retrograde degeneration to the retinal ganglion cells. The pattern electroretinogram (PERG) N95 component is thought to rise in relation to retinal ganglion cell function and hence may be a potential prognostic indicator for visual function following decompressive surgery. METHODS The notes and electrodiagnostic records of 72 eyes from 36 patients with chiasmal compression were retrospectively analysed. RESULTS The postoperative change in visual field was found to be associated with the PERG N95:P50 ratio (p=0.01). Improvement in visual field was shown by a greater proportion of eyes with a normal N95:P50 ratio (65%) than with an abnormal ratio (27%). No change in visual field occurred in 26% of the eyes with a normal N95:P50 ratio compared with 67% of those with an abnormal ratio. Only 8% of eyes showed a worsening of visual field following surgery, in similar proportions for eyes with normal and abnormal N95:P50 ratios. There was no significant relationship with visual acuity. CONCLUSION The PERG is a useful visual prognostic indicator in the preoperative assessment of chiasmal compression.
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Affiliation(s)
- D N Parmar
- Department of Neurosciences, King's College Hospital, London SE5 9RS, UK
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Brecelj J, Stirn-Kranjc B, Skrbec M. Visual electrophysiology in children with tumours affecting the visual pathway. Case reports. Doc Ophthalmol 2000; 101:125-54. [PMID: 11200546 DOI: 10.1023/a:1026521804675] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In 9 children (8-14 years of age) with orbital, suprasellar or postchiasmal tumours, visual loss was studied by visual electrophysiology in relation to ophthalmologic and neuroimaging findings. Pattern electroretinography (PERG) and pattern visual evoked potentials (PVEP) to full and half-field pattern-reversal stimulation were recorded and PERG and PVEP changes were related to the tumour location. PERG wave P50 attenuation was found associated with the central retinal dysfunction in the child with orbital rhabdomyosarcoma; PVEP wave P100 delay was associated with the optic nerve dysfunction in a child with retrobulbar chondrosarcoma and in a child with optic nerve glioma; PVEP wave P100 asymmetry was associated with the crossed fibers dysfunction in a child with hypothalamic germinoma, and PVEP wave P100 uncrossed asymmetry was associated with postchiasmal dysfunction in children with postchiasmal tumours (one with pilocytic astrocytoma and two with angioma). On the other hand, normal PERG suggested that there was no central retinal dysfunction in a child with pleomorphic adenoma of the lacrimal gland, and normal PVEP to full and half-field stimulation excluded visual pathway dysfunction at the chiasm in a child with suprasellar arachnoidal cyst. Follow-up was useful in indicating whether visual dysfunction was progressive or not. We conclude that PERG and PVEP findings contributed to understanding whether the dysfunction originated was at the retina, in the optic nerve, chiasm or postchiasmal pathway.
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Affiliation(s)
- J Brecelj
- Institute of Clinical Neurophysiology, University Medical Centre, Ljubljana, Slovenia.
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Abstract
Recording of visual evoked potentials (VEPs) is not yet a routine test in patients with suspected chiasmal compressive lesions, but has proved useful to a clinician in assessing and following-up visual pathway dysfunctions. Abnormalities of VEPs can be found even in patients without clinical evidence of the visual impairment: VEP delays and alterations of the waveform, asymmetric distribution in one eye or in both eyes (crossed asymmetry) can indicate chiasmal compressive lesion. Simultaneous recording of pattern electroretinograms (PERGs) can additionally provide useful information about the patient's cooperation as well as about eventual retrograde degeneration of the ganglion cells. Electrophysiologic tests can be regarded as an integral part of diagnostic procedures--ocular diagnostic tests and neuroimaging--in suspected compressive lesions of the optic chiasm.
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Affiliation(s)
- J Brecelj
- University Institute of Clinical Neurophysiology, Medical Centre, Ljubljana, Slovenia
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