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Nagarajan S, Prabu R, Parachuri N, Thulasidas M. Electroretinogram as a Screening Tool to Assess Vigabatrin-Induced Retinal Toxicity in Children With Infantile Spasms. J Pediatr Ophthalmol Strabismus 2024; 61:273-278. [PMID: 38482803 DOI: 10.3928/01913913-20240215-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
PURPOSE To assess the utility of electroretinogram (ERG) as a screening tool for vigabatrin-induced retinal toxicity in children with infantile spasms. METHODS This was an observational cohort study including children with infantile spasms receiving treatment with vigabatrin. A 30-Hz flicker potential ERG, using the RETeval system (LKC Technologies), was done at baseline before starting vigabatrin at 6 months and 1 year. The amplitudes were recorded. RESULTS Eleven children were included in the study. The most common etiologic factor for infantile spasms was tuberous sclerosis (36.4%) followed by West syndrome (27.3%). The mean age of the children was 7.14 ± 2.9 months, with a range of 3 to 16 months. The mean difference in amplitude was 3.21 ± 2.45 and 5.72 ± 4.18 µV at 6 and 12 months follow-up, respectively (P < .001). Eight of the 11 children (72.7%) showed vigabatrin-induced retinal toxicity, and all 8 children were receiving vigabatrin for more than 6 months. CONCLUSIONS ERG can be used for vigabatrin-induced retinal toxicity monitoring in children with infantile spasms. Vigabatrin-induced retinal toxicity is related to the duration of treatment rather than cumulative dosage. [J Pediatr Ophthalmol Strabismus. 2024;61(4):273-278.].
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Portengen BL, Porro GL, Imhof SM, Naber M. Comparison of unifocal, flicker, and multifocal pupil perimetry methods in healthy adults. J Vis 2022; 22:7. [PMID: 35998063 PMCID: PMC9424968 DOI: 10.1167/jov.22.9.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
To this day, the most popular method of choice for testing visual field defects (VFDs) is subjective standard automated perimetry. However, a need has arisen for an objective, and less time-consuming method. Pupil perimetry (PP), which uses pupil responses to onsets of bright stimuli as indications of visual sensitivity, fulfills these requirements. It is currently unclear which PP method most accurately detects VFDs. Hence, the purpose of this study is to compare three PP methods for measuring pupil responsiveness. Unifocal (UPP), flicker (FPP), and multifocal PP (MPP) were compared by monocularly testing the inner 60 degrees of vision at 44 wedge-shaped locations. The visual field (VF) sensitivity of 18 healthy adult participants (mean age and SD 23.7 ± 3.0 years) was assessed, each under three different artificially simulated scotomas for approximately 4.5 minutes each (i.e. stimulus was not or only partially present) conditions: quadrantanopia, a 20-, and 10-degree diameter scotoma. Stimuli that were fully present on the screen evoked strongest, partially present stimuli evoked weaker, and absent stimuli evoked the weakest pupil responses in all methods. However, the pupil responses in FPP showed stronger discriminative power for present versus absent trials (median d-prime = 6.26 ± 2.49, area under the curve [AUC] = 1.0 ± 0) and MPP performed better for fully present versus partially present trials (median d-prime = 1.19 ± 0.62, AUC = 0.80 ± 0.11). We conducted the first in-depth comparison of three PP methods. Gaze-contingent FPP had best discriminative power for large (absolute) scotomas, whereas MPP performed slightly better with small (relative) scotomas.
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Affiliation(s)
- Brendan L Portengen
- Ophthalmology Department, University Medical Center Utrecht, The Netherlands.,Experimental Psychology, Helmholtz Institute, Utrecht University, The Netherlands.,
| | - Giorgio L Porro
- Ophthalmology Department, University Medical Center Utrecht, The Netherlands.,
| | - Saskia M Imhof
- Ophthalmology Department, University Medical Center Utrecht, The Netherlands.,
| | - Marnix Naber
- Experimental Psychology, Helmholtz Institute, Utrecht University, The Netherlands.,
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Gekova MV. FEATURES OF USING THE EVOQUED POTENTIAL METHOD IN CHILDREN WITH EPILEPSY. BULLETIN OF PROBLEMS BIOLOGY AND MEDICINE 2022. [DOI: 10.29254/2077-4214-2022-4-167-23-34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- M. V. Gekova
- State Institution "Institute of Neurology, Psychiatry and Narcology of the National Academy of Medical Sciences of Ukraine"
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O'Neill EK, Smith R. Visual electrophysiology in the assessment of toxicity and deficiency states affecting the visual system. Eye (Lond) 2021; 35:2344-2353. [PMID: 34290445 PMCID: PMC8377028 DOI: 10.1038/s41433-021-01663-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 02/07/2023] Open
Abstract
Visual disturbance or visual failure due to toxicity of an ingested substance or a severe nutritional deficiency can present significant challenges for diagnosis and management, for instance, where an adverse reaction to a prescribed medicine is suspected. Objective assessment of visual function is important, particularly where structural changes in the retina or optic nerve have not yet occurred, as there may be a window of opportunity to mitigate or reverse visual loss. This paper reviews a number of clinical presentations where visual electrophysiological assessment has an important role in early diagnosis or management alongside clinical assessment and ocular imaging modalities. We highlight the importance of vitamin A deficiency as an easily detected marker for severe combined micronutrient deficiency.
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Affiliation(s)
- Emily K O'Neill
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK. Emily.O'
| | - Richard Smith
- Eye Department, Stoke Mandeville Hospital, Aylesbury, Buckinghamshire, 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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Clinical implications and cost of electroretinography screening for vigabatrin toxicity. Can J Ophthalmol 2020; 55:e98-e100. [DOI: 10.1016/j.jcjo.2019.10.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/03/2019] [Accepted: 10/31/2019] [Indexed: 11/17/2022]
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Neumayr L, Pieper T, Kudernatsch M, Trauzettel-Klosinski S, Staudt M. Uncovering homonymous visual field defects in candidates for pediatric epilepsy surgery. Eur J Paediatr Neurol 2020; 25:165-171. [PMID: 31784289 DOI: 10.1016/j.ejpn.2019.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 08/03/2019] [Accepted: 11/17/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Perimetry in children can be challenging due to low cooperation and short attention span. Especially during the pre-surgical work-up of children with pharmaco-refractory epilepsies, however, diagnosing homonymous visual field defects (HVFDs) can be crucial for planning surgical strategies. Here, we evaluated "campimetry" for visual field testing in children. Furthermore, we analyzed strabismus and anomalous head posture as clinical signs for HVFDs. METHODS Campimetry and a standard orthoptic examination were performed in 18 patients (age range: 3 y 2 m-18 y) who underwent epilepsy surgeries in our center during the study period, and in 11 additional patients (age range: 2 y 10 m-22 y 10 m) with suspected or confirmed HVFDs. RESULTS In 16/18 patients of our unselected surgery cohort, pre- and postoperative campimetry was successfully completed. Of these, only 7/16 patients had intact visual fields pre- and postoperatively, while 5/16 patients already showed preoperative HVFDs and 4/16 patients suffered newly acquired HVFDs as calculated consequences of the surgery. Regarding clinical signs, strabismus (mostly esotropia) and anomalous head posture were specific indicators of HVFDs (strabismus: 6/12 with HVFDs vs 1/18 without; anomalous head posture: 8/12 with HVFDs vs 0/18 without). CONCLUSIONS For perimetry in children with limited cooperation, we suggest campimetry as it allows early detection and fast delineation of HVFDs. This is particularly important in pediatric epilepsy surgery patients, who display a surprisingly high proportion of HVFDs (9/16). Both, strabismus and anomalous head posture can indicate such HVFDs. Therefore, clinicians should pay attention to these clinical signs, especially in the context of epilepsy surgery.
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Affiliation(s)
- Lisa Neumayr
- Clinic for Neuropediatrics and Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen Klinik Vogtareuth, Vogtareuth, Germany; Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital, Tübingen, Germany.
| | - Tom Pieper
- Clinic for Neuropediatrics and Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen Klinik Vogtareuth, Vogtareuth, Germany
| | - Manfred Kudernatsch
- Clinic for Neuropediatrics and Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen Klinik Vogtareuth, Vogtareuth, Germany; Research Institute "Rehabilitation, Transition, Palliation" PMU Salzburg, Salzburg, Austria
| | | | - Martin Staudt
- Clinic for Neuropediatrics and Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen Klinik Vogtareuth, Vogtareuth, Germany; Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital, Tübingen, Germany
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Central and peripheral steady-state visual evoked potentials in children with optic pathway gliomas. Doc Ophthalmol 2019; 139:137-149. [PMID: 31243619 DOI: 10.1007/s10633-019-09703-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 06/19/2019] [Indexed: 01/23/2023]
Abstract
PURPOSE Treatment of optic pathway gliomas is prompted by neuroradiological evidence of tumor growth, usually associated with progressive visual loss. Despite therapy, approximately 40% will show visual deterioration. Treatment outcome is largely based on the preservation of vision. However, current visual function assessment is often unreliable in children with optic pathway gliomas who have limited collaboration. Thus, there is a need for new clinical tools to evaluate visual functions in these children. The aim of the study was to assess the value of steady-state visual evoked potentials as a tool to assess function in the central and peripheral visual fields of children with optic pathway gliomas. METHOD Ten patients with optic pathway gliomas and 33 healthy controls (ages 3 to 18 years) were tested using steady-state visual evoked potentials. The dartboard stimulus consisted of one central circle alternating at 16 reversals/s and one peripheral hoop alternating at 14.4 reversals/s, separated by a hoop of gray space. It was presented monocularly at 30% and 96% contrasts. RESULTS Results indicated that central signal-to-noise ratios were significantly lower in children with optic pathway gliomas compared to controls. However, no significant group difference was detected in the peripheral visual field. CONCLUSION Steady-state visual evoked potentials could eventually be implemented in the clinical assessment and follow-up of central visual field deficits in uncooperative or nonverbal children but seem to have limited usefulness for evaluation of peripheral visual field deficits. Additional studies are needed to identify testing parameters for full visual field assessment.
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Hébert-Lalonde N, Carmant L, Major P, Roy MS, Lassonde M, Saint-Amour D. Electrophysiological Evidences of Visual Field Alterations in Children Exposed to Vigabatrin Early in Life. Pediatr Neurol 2016; 59:47-53. [PMID: 27105764 DOI: 10.1016/j.pediatrneurol.2016.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/04/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND We assessed central and peripheral visual field processing in children with epilepsy who were exposed to vigabatrin during infancy. METHODS Steady-state visual evoked potentials and pattern electroretinograms to field-specific radial checkerboards flickering at two cycle frequencies (7.5 and 6 Hz for central and peripheral stimulations, respectively) were recorded from Oz and at the eye in seven school-age children (10.1 ± 3.5 years) exposed to vigabatrin early in life, compared with children early exposed to other antiepileptic drugs (n = 9) and healthy children (n = 8). The stimulation was made of two concentric circles (0 to 5 and 30 to 60 degrees of angle) and presented at four contrast levels (96%, 64%, 32%, and 16%). RESULTS Ocular responses were similar in all groups for central but not for the peripheral stimulations, which were significantly lower in the vigabatrin-exposed group at high contrast level. This peripheral retinal response was negatively correlated to vigabatrin exposure duration. Cortical responses to central stimulations, including contrast response functions in the children with epilepsy in both groups, were lower than those in normally developing children. CONCLUSIONS Alteration of ocular processing was found only in the vigabatrin-exposed children. Central cortical processing, however, was impaired in both epileptic groups, with more pronounced effects in vigabatrin-exposed children. Our study suggests that asymptomatic long-term visual toxicity may still be present at school age, even several years after discontinuation of drug therapy.
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Affiliation(s)
- Noémie Hébert-Lalonde
- Department of Psychology, Université de Montréal, Montreal, Quebec, Canada; Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Lionel Carmant
- Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada; Division of Neurology, Department of Pediatrics, Sainte-Justine Hospital, Université de Montréal, Montreal, Quebec, Canada
| | - Philippe Major
- Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada; Division of Neurology, Department of Pediatrics, Sainte-Justine Hospital, Université de Montréal, Montreal, Quebec, Canada
| | | | - Maryse Lassonde
- Department of Psychology, Université de Montréal, Montreal, Quebec, Canada; Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Dave Saint-Amour
- Research Center, CHU Sainte-Justine, Montreal, Quebec, Canada; Department of Ophtalmology, Université de Montréal, Montreal, Quebec, Canada; Department of Psychology, Université du Québec à Montréal, Montreal, Quebec, Canada.
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Varcin KJ, Nelson CA, Ko J, Sahin M, Wu JY, Jeste SS. Visual Evoked Potentials as a Readout of Cortical Function in Infants With Tuberous Sclerosis Complex. J Child Neurol 2016; 31:195-202. [PMID: 26018199 PMCID: PMC5472095 DOI: 10.1177/0883073815587328] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 04/15/2015] [Indexed: 11/17/2022]
Abstract
Tuberous sclerosis complex is an autosomal dominant genetic disorder that confers a high risk for neurodevelopmental disorders, such as autism spectrum disorder and intellectual disability. Studies have demonstrated specific delays in visual reception skills that may predict the development of autism spectrum disorder and intellectual disability. Based on evidence for alterations in the retinogeniculate pathway in animal models of tuberous sclerosis complex, we asked whether children with tuberous sclerosis complex demonstrate alterations in early visual processing that may undermine the development of higher-level visual behaviors. Pattern-reversal visual evoked potentials were recorded in infants with tuberous sclerosis complex (n = 16) and typically developing infants (n = 18) at 12 months of age. Infants with tuberous sclerosis complex demonstrated remarkably intact visual evoked potentials even within the context of intellectual disability and epilepsy. Infants with tuberous sclerosis complex show intact visual cortical processing, suggesting that delays in visually mediated behaviors in tuberous sclerosis complex may not be rooted in early visual processing deficits.
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Affiliation(s)
- Kandice J Varcin
- Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Charles A Nelson
- Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA. Graduate School of Education, Harvard University, Boston, MA, USA
| | - Jordan Ko
- Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Joyce Y Wu
- Division of Pediatric Neurology, Mattel Children's Hospital at University of California, Los Angeles, CA, USA
| | - Shafali Spurling Jeste
- Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
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Westall CA, Wright T, Cortese F, Kumarappah A, Snead OC, Buncic JR. Vigabatrin retinal toxicity in children with infantile spasms: An observational cohort study. Neurology 2014; 83:2262-8. [PMID: 25381295 PMCID: PMC4277676 DOI: 10.1212/wnl.0000000000001069] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 07/07/2014] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES To determine time to vigabatrin (VGB, Sabril; Lundbeck, Deerfield, IL) induced retinal damage in children with infantile spasms (IS) and to identify risk factors for VGB-induced retinal damage (VGB-RD). METHODS Observational cohort study including 146 participants (68 female, 81 male) with IS, an age-specific epilepsy syndrome of early infancy, treated with VGB. Participants ranged from 3 to 34.9 months of age (median 7.6 months). The median duration of VGB treatment was 16 months (range 4.6-78.5 months). Electroretinograms (ERGs) were performed according to the Standards of the International Society for Clinical Electrophysiology of Vision. Inclusion required baseline (pre-VGB or within 4 weeks of starting VGB treatment) and at least 2 follow-up ERGs. Significant reduction from baseline of the 30-Hz ERG flicker amplitude on 2 consecutive visits identified VGB-RD. Kaplan-Meier survival analyses depicted the effect of duration of VGB on VGB-RD. RESULTS These data represent the largest survival analysis of children treated with VGB who did not succumb to retinal toxicity during the study. Thirty of the 146 participants (21%) showed VGB-RD. The ERG amplitude reduced with duration of VGB treatment (p = 0.0004) with no recovery after VGB cessation. With 6 and 12 months of VGB treatment, 5.3% and 13.3%, respectively, developed VGB-RD. There was neither effect of age of initiation of VGB treatment nor sex of the child on survival statistics and no significant effect of cumulative dosage on the occurrence of VGB-RD. CONCLUSIONS Minimizing VGB treatment to 6 months will reduce the prevalence of VGB-RD in patients with IS.
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Affiliation(s)
- Carol A Westall
- From the Department of Ophthalmology and Vision Science (C.A.W., T.W., A.K., J.R.B.), and Faculty of Medicine (O.C.S.), The Hospital for Sick Children, University of Toronto (C.A.W., J.R.B., O.C.S.); and Hotchkiss Brain Institute, University of Calgary (F.C.), Canada.
| | - Tom Wright
- From the Department of Ophthalmology and Vision Science (C.A.W., T.W., A.K., J.R.B.), and Faculty of Medicine (O.C.S.), The Hospital for Sick Children, University of Toronto (C.A.W., J.R.B., O.C.S.); and Hotchkiss Brain Institute, University of Calgary (F.C.), Canada
| | - Filomeno Cortese
- From the Department of Ophthalmology and Vision Science (C.A.W., T.W., A.K., J.R.B.), and Faculty of Medicine (O.C.S.), The Hospital for Sick Children, University of Toronto (C.A.W., J.R.B., O.C.S.); and Hotchkiss Brain Institute, University of Calgary (F.C.), Canada
| | - Ananthavalli Kumarappah
- From the Department of Ophthalmology and Vision Science (C.A.W., T.W., A.K., J.R.B.), and Faculty of Medicine (O.C.S.), The Hospital for Sick Children, University of Toronto (C.A.W., J.R.B., O.C.S.); and Hotchkiss Brain Institute, University of Calgary (F.C.), Canada
| | - O Carter Snead
- From the Department of Ophthalmology and Vision Science (C.A.W., T.W., A.K., J.R.B.), and Faculty of Medicine (O.C.S.), The Hospital for Sick Children, University of Toronto (C.A.W., J.R.B., O.C.S.); and Hotchkiss Brain Institute, University of Calgary (F.C.), Canada
| | - Joseph R Buncic
- From the Department of Ophthalmology and Vision Science (C.A.W., T.W., A.K., J.R.B.), and Faculty of Medicine (O.C.S.), The Hospital for Sick Children, University of Toronto (C.A.W., J.R.B., O.C.S.); and Hotchkiss Brain Institute, University of Calgary (F.C.), Canada
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A frequency-tagging electrophysiological method to identify central and peripheral visual field deficits. Doc Ophthalmol 2014; 129:17-26. [PMID: 24817488 DOI: 10.1007/s10633-014-9439-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 04/29/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND The aim of this study was to develop a fast and efficient electrophysiological protocol to examine the visual field's integrity, which would be useful in pediatric testing. METHODS Steady-state visual-evoked potentials (ssVEPs) to field-specific radial checkerboards flickering at two cycle frequencies (7.5 and 6 Hz for central and peripheral stimulations, respectively) recorded at Oz were collected from 22 participants from 5 to 34 years old and from 5 visually impaired adolescents (12-16 years old). Responses from additional leads (POz, O1, O2), and the impact of gaze deviation on the signals, were also investigated in a subgroup of participants. RESULTS Steady-state visual-evoked potentials responses were similar at all electrode sites, although the signal from the central stimulation was significantly higher at Oz and was highly sensitive in detecting gaze deviation. No effect of age or sex was found, indicating similar ssVEP responses between adults and healthy children. Visual acuity was related to the central signal when comparing healthy participants with four central visual impaired adolescents. Clinical validation of our electrophysiological protocol was also achieved in a 15-year-old adolescent with a severe peripheral visual deficit, as assessed with Goldmann perimetry. CONCLUSIONS A single electrode over Oz is sufficient to gather both central and peripheral visual signals and also to control for gaze deviation. Our method presents several advantages in evaluating visual fields integrity, as it is fast, reliable, and efficient, and applicable in children as young as 5 years old. However, a larger sample of healthy children should be tested to establish clinical norms.
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Curatolo P, D’Argenzio L, Cerminara C, Bombardieri R. Management of epilepsy in tuberous sclerosis complex. Expert Rev Neurother 2014; 8:457-67. [DOI: 10.1586/14737175.8.3.457] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Yadav NK, Ludlam DP, Ciuffreda KJ. Effect of different stimulus configurations on the visual evoked potential (VEP). Doc Ophthalmol 2012; 124:177-96. [PMID: 22426575 DOI: 10.1007/s10633-012-9319-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 03/02/2012] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to assess changes in the response profile of the pattern visual evoked potential (VEP) using three stimulus configurations simulating visual-field scotomas: central circular and central blank fields increasing incrementally in diameter from 1° to 15°, hemi-field, and quadrant patterns. Five visually normal adult subjects (ages 22-68 years) were tested binocularly at 1 m for each stimulus configuration on 5 separate days. A checkerboard test pattern (64 × 64 black-and-white checks, 85% contrast, 64 cd/m(2) luminance, 20 s of stimulus duration, 2-Hz temporal frequency) was used. The group mean VEP amplitude increased in a linear manner with increase in the central circular diameter (y = 0.805x + 2.00; r = 0.986) and decrease in central blank field diameter (y = -0.769x + 16.22; r = 0.987). There was no significant change in latency in nearly all cases. The group mean coefficient of variability results indicated that the VEP amplitude was repeatable for the different stimulus configurations. The finding of VEP response linearity for the circular stimulus fields, and repeatability for all stimulus configurations, suggests that the clinician may be able to use the VEP technique with the suggested test patterns as a rapid and simple tool for objective assessment for several types of visual-field defects for a range of abnormal visual conditions and special populations.
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Affiliation(s)
- Naveen K Yadav
- Department of Biological and Vision Sciences, SUNY State College of Optometry, New York, NY 10036, USA.
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Báez Martín MM, del Carmen Pérez Téllez Y, Chacón LMM, Díaz BE, Trápaga-Quincoses O, Maeso IG, Bender JE, Galvizu R, García ME, Abreu IC, Rodríguez GS. Innovative evaluation of visual field defects in epileptic patients after standard anterior temporal lobectomy, using partial field visual evoked potentials. Epilepsy Res 2010; 90:68-74. [PMID: 20427151 DOI: 10.1016/j.eplepsyres.2010.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 03/10/2010] [Accepted: 03/12/2010] [Indexed: 01/16/2023]
Abstract
The purpose of this paper is to obtain an electrophysiological evaluation of visual field defects consecutive to the direct lesion of optic radiations in drug-resistant epileptic patients after a standard electrocorticographically adjusted lobectomy, and to correlate it with conventional perimetric results, and with the volume of resected tissue during surgical treatment. Twenty-four patients with temporal lobe epilepsy defined through long term EEG-video, ictal and interictal SPECT, as well as Magnetic Resonance Imaging were studied. Visual evoked potentials (VEPs) with partial and total visual field stimulation were carried out before and after 6, 12 and 24 months surgical treatment. A control group was also studied. No differences between patients and control subjects were observed during the evaluation of the full-field VEPs. However, there were statistical differences between groups in the half-field VEP recordings and in the VEP recordings of contralateral to resected side superior quadrant (CSQ) before lobectomy and 6 months later (Mann-Whitney's U-test, p<0.05). Significant associations were found between VEP abnormalities and perimetric results in CSQ. A close relationship between perimetry, VEPs and volume of the resected tissue in hippocampus, parahippocampus, medial and lower temporal giri was also found. Visual field defects consecutive to standard temporal lobe resection in epileptic patients could be objectively evaluated by partial stimulation VEPs corresponding to the size of resected tissue.
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Sergott RC, Wheless JW, Smith MC, Westall CA, Kardon RH, Arnold A, Foroozan R, Sagar SM. Evidence-based Review of Recommendations for Visual Function Testing in Patients Treated with Vigabatrin. Neuroophthalmology 2010. [DOI: 10.3109/01658100903582498] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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James Willmore L, Abelson MB, Ben-Menachem E, Pellock JM, Donald Shields W. Vigabatrin: 2008 Update. Epilepsia 2009; 50:163-73. [DOI: 10.1111/j.1528-1167.2008.01988.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Gaily E, Jonsson H, Lappi M. Visual fields at school-age in children treated with vigabatrin in infancy. Epilepsia 2009; 50:206-16. [DOI: 10.1111/j.1528-1167.2008.01961.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Waterhouse EJ, Mims KN, Gowda SN. Treatment of refractory complex partial seizures: role of vigabatrin. Neuropsychiatr Dis Treat 2009; 5:505-15. [PMID: 19851518 PMCID: PMC2762367 DOI: 10.2147/ndt.s5236] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Vigabatrin (VGB) is an antiepileptic drug that was designed to inhibit GABA-transaminase, and increase levels of gamma-amino-butyric acid (GABA), a major inhibitory neurotransmitter in the brain. VGB has demonstrated efficacy as an adjunctive antiepileptic drug for refractory complex partial seizures (CPS) and for infantile spasms (IS). This review focuses on its use for complex partial seizures. Although VGB is well tolerated, there have been significant safety concerns about intramyelinic edema and visual field defects. VGB is associated with a risk of developing bilateral concentric visual field defects. Therefore, the use of VGB for complex partial seizures should be limited to those patients with seizures refractory to other treatments. Patients must have baseline and follow-up monitoring of visual fields, early assessment of its efficacy, and ongoing evaluation of the benefits and risks of VGB therapy.
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Affiliation(s)
- Elizabeth J Waterhouse
- Department of Neurology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
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Abstract
Tuberous sclerosis is a genetic multisystem disorder characterised by widespread hamartomas in several organs, including the brain, heart, skin, eyes, kidney, lung, and liver. The affected genes are TSC1 and TSC2, encoding hamartin and tuberin respectively. The hamartin-tuberin complex inhibits the mammalian-target-of-rapamycin pathway, which controls cell growth and proliferation. Variations in the distribution, number, size, and location of lesions cause the clinical syndrome to vary, even between relatives. Most features of tuberous sclerosis become evident only in childhood after 3 years of age, limiting their usefulness for early diagnosis. Identification of patients at risk for severe manifestations is crucial. Increasing understanding of the molecular abnormalities caused by tuberous sclerosis may enable improved management of this disease.
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Affiliation(s)
- Paolo Curatolo
- Department of Neurosciences, Paediatric Neurology Unit, Tor Vergata University, Rome, Italy
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The ocular side effects of vigabatrin (Sabril): information and guidance for screening. Eye (Lond) 2008; 22:1097-8. [PMID: 18497834 DOI: 10.1038/eye.2008.139] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Parisi P, Bombardieri R, Curatolo P. Current role of vigabatrin in infantile spasms. Eur J Paediatr Neurol 2007; 11:331-6. [PMID: 17625936 DOI: 10.1016/j.ejpn.2007.03.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 03/25/2007] [Accepted: 03/26/2007] [Indexed: 11/22/2022]
Abstract
Vigabatrin (VGB), a selective irreversible inhibitor of gamma-aminobutyric acid transaminase, has proved to be effective against cryptogenic and symptomatic infantile spasms (IS). Unfortunately, reports of serious visual field defects have led to a drastic reduction in the use of the drug. This review is based on a systematic search in the literature for evidence regarding efficacy and safety of VGB in IS. Based on a specific mechanism of action, there is a solid evidence of clinical efficacy of VGB in children with Tuberous Sclerosis. Similarly, VGB could represent a potential effective therapy also for spasms due to focal cortical dysplasia. In infants with spasms due to other causes, the risk of ophthalmologic toxicity should be carefully weighted against the benefit of controlling spasms.
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Affiliation(s)
- Pasquale Parisi
- Child Neurology & Paediatric Sleep Centre, La Sapienza II University c/o Sant'Andrea Hospital, Rome, Italy
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Wild JM, Ahn HS, Baulac M, Bursztyn J, Chiron C, Gandolfo E, Safran AB, Schiefer U, Perucca E. Vigabatrin and Epilepsy: Lessons Learned. Epilepsia 2007; 48:1318-27. [PMID: 17635558 DOI: 10.1111/j.1528-1167.2007.01133.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE The risk factors for visual field loss attributable to vigabatrin (VAVFL) are equivocal. This multinational, prospective, observational study aimed to clarify the principal/major factors for VAVFL. METHODS Interim analysis of three groups with refractory partial epilepsy, stratified by age (8-12 years; >12 years) and exposure to vigabatrin (VGB). Group I comprised participants treated with VGB for >or=6 months, Group II participants previously treated with VGB for >or=6 months who had discontinued the drug for >or=6 months and Group III those never treated with VGB. Perimetry was undertaken at least every six months, for up to 36 months; results were evaluated masked to drug exposure. RESULTS Based upon 563 participants in the locked data set, 432 yielded one or more Conclusive visual field examinations. For Group I, the frequency of VAVFL at the last Conclusive examination was 10/32 (31.2%) for those aged 8-12 years and 52/125 (41.6%) for those aged >12 years. For Group II, the proportions were 4/39 (10.3%) and 31/129 (24.0%). No cases resembling VAVFL manifested in Group III. VAVFL was associated with duration of VGB therapy (Odds ratio [OR] 14.2; 95% CI 5.0 to 40.5); mean dose of VGB (OR 8.5; 95% CI 2.2 to 33.2); and male gender (OR 2.1; 95% CI 1.2 to 3.7). VAVFL was more common with static than kinetic perimetry (OR 2.3, 95% CI 1.3 to 4.2). CONCLUSIONS The therapeutic benefit of VGB is counteracted by the progressive accrual of the risk of VAVFL with continued exposure and with increase in mean dose.
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Affiliation(s)
- John M Wild
- Cardiff School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom.
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Verrotti A, Manco R, Matricardi S, Franzoni E, Chiarelli F. Antiepileptic drugs and visual function. Pediatr Neurol 2007; 36:353-60. [PMID: 17560495 DOI: 10.1016/j.pediatrneurol.2007.03.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 12/20/2006] [Accepted: 03/22/2007] [Indexed: 01/23/2023]
Abstract
Antiepileptic drugs are known to result in visual disturbances. A number of antiepileptic drugs have recently been reported to result in various abnormalities of vision, particularly deficiencies in visual fields and color vision. Moreover, there has been a marked improvement in the diagnosis and understanding of the pathophysiology of visual disturbance. This review collects evidence for visual adverse effects induced by the older antiepileptic drugs (barbiturates, benzodiazepine, carbamazepine, valproic acid, ethosuximide, and phenytoin) and the newer ones (vigabatrin, topiramate, tiagabine, levetiracetam, lamotrigine, gabapentin, felbamate, and oxcarbazepine).
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Henriques-Souza AMDM, Ataide Junior L, Laurentino SG. [Treatment of West syndrome with vigabatrin: clinical and electroencephalographic evaluation of 13 patients]. ARQUIVOS DE NEURO-PSIQUIATRIA 2007; 65:144-49. [PMID: 17420838 DOI: 10.1590/s0004-282x2007000100029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Accepted: 10/04/2006] [Indexed: 11/22/2022]
Abstract
We evaluated the efficacy of vigabatrin (VGB) as a first drug to be used as monotherapy for West syndrome (WS), its side effects and correlations with the electroencephalogram (EEG). The sample consisted of 13 infants examined between October 2001 and September 2002 at IMIP ambulatory patients office or private clinic. Administration of vigabatrin was around 118 mg/kg/day. Suppression of spasms was obtained in 4 children (31%), partial control in 3 (23%), 5 of them did not present therapeutic response (38%) and just one (8%) got worse. On the two patients with tuberous sclerosis, one was seizure-free and in another there was partial control. Side effects happened in 8 children (62%) and consisted of irritability, insomnia, somnolence and agitation, and all of them have been well tolerated. The second EEG showed disappearance of hipsarrhythmia in 6 patients (46%). Four of these were seizure-free. We conclude that VGB is effective and well tolerated as initial monotherapy for WS.
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Abstract
Refractory epilepsies such as infantile spasms (IS) and complex partial seizures (CPS) can have a severe negative impact on the neurological integrity and quality of life of affected patients, in addition to drastically increasing their risk of premature mortality. Early identification of potentially effective pharmacotherapy agents is important. Vigabatrin has been shown to be a generally well tolerated and effective antiepileptic drug (AED) in a wide variety of seizure types affecting both children and adults, particularly those with IS and CPS. A bilateral, concentric constriction of the peripheral visual field characterizes the visual field defect (VFD) associated with vigabatrin, well characterized by numerous studies. This peripheral VFD presents in 30-50% of patients with exposure of several years; however, most of these patients are asymptomatic. In well-controlled studies, the earliest onset in patients with CPS is 11 months and at 5 months in infants, with average onsets being more than 5 years and 1 year, respectively. Patients with a peripheral VFD retain an average 65 degrees of lateral vision (normal, 90 degrees). The fact that many patients never develop the vigabatrin-related peripheral VFD, despite long-term exposure at high doses, may support the hypothesis that the injury is an idiosyncratic adverse drug reaction (as opposed to a strict dose- or duration-dependent toxicity). Effective testing methods are available to aid in the early detection and management of the peripheral VFD. This article discusses issues of importance to clinical decision-making in the use of vigabatrin to assist the physician and patient in assessing the benefits of vigabatrin therapy and understanding the potential risks of the VFD and uncontrolled seizures.
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Affiliation(s)
- James W. Wheless
- Le Bonheur Children’s Medical Center, University of Tennessee Health Science Center, Memphis, Tennessee
| | - R. Eugene Ramsay
- University of Miami/Jackson Memorial Medical Center, Miami, Florida
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Bialer M, Johannessen SI, Kupferberg HJ, Levy RH, Perucca E, Tomson T. Progress report on new antiepileptic drugs: a summary of the Eigth Eilat Conference (EILAT VIII). Epilepsy Res 2006; 73:1-52. [PMID: 17158031 DOI: 10.1016/j.eplepsyres.2006.10.008] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Accepted: 10/30/2006] [Indexed: 12/15/2022]
Abstract
The Eigth Eilat Conference on New Antiepileptic Drugs (AEDs)-EILAT VII, took place in Sitges, Barcelona from the 10th to 14th September, 2006. Basic scientists, clinical pharmacologists and neurologists from 24 countries attended the conference, whose main themes included a focus on status epilepticus (epidemiology, current and future treatments), evidence-based treatment guidelines and the potential of neurostimulation in refractory epilepsy. Consistent with previous formats of this conference, the central part of the conference was devoted to a review of AEDs in development, as well as updates on marketed AEDs introduced since 1989. This article summarizes the information presented on drugs in development, including brivaracetam, eslicarbazepine acetate (BIA-2-093), fluorofelbamate, ganaxolone, huperzine, lacosamide, retigabine, rufinamide, seletracetam, stiripentol, talampanel, valrocemide, JZP-4, NS1209, PID and RWJ-333369. Updates on felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine and new extended release oxcarbazepine formulations, pregabalin, tiagabine, topiramate, vigabatrin, zonisamide and new extended release valproic acid formulations, and the antiepileptic vagal stimulator device are also presented.
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Affiliation(s)
- Meir Bialer
- Department of Pharmaceutics, School of Pharmacy, David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel.
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Kim YJ, Yukawa E, Kawasaki K, Nakase H, Sakaki T. Use of multifocal visual evoked potential tests in the objective evaluation of the visual field in pediatric epilepsy surgery. J Neurosurg 2006; 104:160-5. [PMID: 16572632 DOI: 10.3171/ped.2006.104.3.160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT To evaluate objectively the visual fields of patients with pediatric epilepsy who are uncooperative with perimetry and in whom postoperative visual field deficits are expected, the authors investigated the usefulness of the multifocal visual evoked potential (VEP) method. METHODS Normal waves in multifocal VEP were determined in 21 healthy children (21 eyes) 6 to 15 years of age (mean 11.4 years). Responses from eight sites in each child were divided into four quadrants (superior and inferior temporal and superior and inferior nasal). In each quadrant, two response waves were grouped and averaged. The peak latency and amplitude at approximately 100 msec were used for assessment. In three cases involving patients with epilepsy, multifocal VEP measurements were also recorded and compared with the peak latency and amplitude in the healthy children. In these children, no significant differences were observed in the peak latency of amplitude among four quadrants using one-way analysis of variance. In each patient, multifocal VEP tests showed abnormal waves in the quadrant corresponding to the lesion demonstrated in neuroradiological images. This result was useful in the treatment of choice and the postoperative evaluation. CONCLUSIONS Multifocal VEP tests can be useful in evaluating the visual field of children objectively. They can also be valuable in assessing preoperative visual field defects and revealing changes in the visual field after treatment.
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Affiliation(s)
- Yeong-Jin Kim
- Department of Neurosurgery, Nara Medical University, Kashihara, Japan.
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Azam M, Bhatti N, Krishin J. Use of ACTH and prednisolone in infantile spasms: Experience from a developing country. Seizure 2005; 14:552-6. [PMID: 16183305 DOI: 10.1016/j.seizure.2005.08.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Adrenocorticotrophic hormone (ACTH) and prednisone are both used to treat infantile spasms (IS) in West syndrome. In many countries, ACTH is expensive and difficult to obtain whereas, prednisone or prednisolone are cheap, given orally and easily available. AIMS The purpose of this retrospective data analysis was to compare the efficacy and cost of ACTH and prednisolone in the treatment of IS from the perspective of a developing country. METHODS Patients admitted with West syndrome in Children's Hospital, Islamabad, between January 1995 and December 2001 were included in the analysis. The diagnosis was made after eliciting a history of characteristic seizures and detecting hypsarrhythmia on the EEG. Parents were offered the use of either ACTH administered by intramuscular injection or prednisolone given orally. ACTH was expensive and difficult to obtain whereas prednisolone was cheap and easily available. RESULTS One hundred and five children were included in the study. Sixty-three were boys and their age ranged from 2 months to 3 years with a mean of 11 months. Thirty-three children received ACTH injections; 27 showed improvement and 11 remained spasms free after discontinuation of injections. Seventy-two patients were given oral prednisolone, 51 responded and 17 remained spasms free after oral steroids were stopped. Overall outcome was similar in both groups. The cost of ACTH injection was more than 100 times the cost of oral prednisolone. CONCLUSION No significant difference was seen in the final outcome in both treatment groups. Since prednisolone is inexpensive, easily available and given orally, it is the preferred mode of therapy.
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Affiliation(s)
- Matloob Azam
- Children's Hospital, Pakistan Institute of Medical Sciences, Islamabad, Pakistan.
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Abstract
Treatments used for several neurological conditions may adversely affect the eye. Vigabatrin-related retinal toxicity leads to a visual field defect. Optic neuropathy may result from ethambutol and isoniazid, and from radiation therapy. Posterior subcapsular cataract is associated with systemic corticosteroids. Transient refractive error changes may follow treatment with acetazolamide or topiramate, and corneal deposits and keratitis with amandatine. Intraocular pressure can be elevated in susceptible individuals by anticholinergic drugs, including oxybutynin, tolterodine, benzhexol, propantheline, atropine and amitriptyline, and also by systemic corticosteroids and by topiramate. Nystagmus, diplopia and extraocular muscle palsies can occur with antiepileptic drugs, particularly phenytoin and carbamazepine. Ocular neuromyotonia can follow parasellar radiation. Congenital ocular malformations can result from in utero exposure to maternally prescribed sodium valproate, phenytoin and carbamazepine. Neurologists must be aware of potential ocular toxicity of these drugs, and appropriately monitor for potential adverse events.
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Affiliation(s)
- S Hadjikoutis
- Department of Neurology, University Hospital of Wales, Cardiff, UK.
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Yukawa E, Kim YJ, Kawasaki K, Taketani F, Hara Y. A Child with Epilepsy in Whom Multifocal VEPs Facilitated the Objective Measurement of the Visual Field. Epilepsia 2005; 46:577-9. [PMID: 15816954 DOI: 10.1111/j.0013-9580.2005.48204.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE We investigated whether visual field defects can be objectively evaluated by using multifocal visual evoked potential (multifocal VEP) in children with epilepsy in whom it is difficult to measure the visual field. METHODS First, to determine normal waves in multifocal VEP, recording was performed by using a VERIS Junior Science (Mayo, Aichi, Japan) in 21 healthy children (21 eyes) consisting of 12 boys and nine girls aged 6 to 15 years (mean age, 11.4 years). Responses from eight sites in each subject were divided into four quadrants (superior and inferior temporal quadrants and superior and inferior nasal quadrants). In each quadrant, two response waves were grouped and averaged; peak latency and amplitude were used for assessment. In a child with epilepsy in whom kinetic or static perimetry was impossible, multifocal VEPs were recorded and compared with the peak latency and amplitude in the healthy subjects. RESULTS In the 21 healthy children, no significant differences were observed in the peak latency or amplitude among four quadrants by one-way analysis of variance. Multifocal VEPs in the child with epilepsy showed abnormal waves in the right hemivisual field, which corresponded to the lesion observed with magnetic resonance imaging. CONCLUSIONS The objective evaluation of visual field defects by using multifocal VEP may be useful in children with epilepsy in whom kinetic/static perimetry as a subjective examination is difficult.
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Affiliation(s)
- Eiichi Yukawa
- Department of Ophthalmology, Nara Medical University, Nara, Japan.
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Chapter 11 Assessment of vision in infants and young children. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1567-4231(09)70208-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Buncic JR, Westall CA, Panton CM, Munn JR, MacKeen LD, Logan WJ. Characteristic retinal atrophy with secondary "inverse" optic atrophy identifies vigabatrin toxicity in children. Ophthalmology 2004; 111:1935-42. [PMID: 15465561 PMCID: PMC3880364 DOI: 10.1016/j.ophtha.2004.03.036] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Accepted: 03/15/2004] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To describe the clinical pattern of retinal atrophy in children caused by the anticonvulsant vigabatrin. DESIGN An interventional case series report. PARTICIPANTS One hundred thirty-eight patients, mainly infants, were evaluated regularly for evidence of possible vigabatrin toxicity in the Eye and Neurology clinics at the Hospital for Sick Children, Toronto. METHOD Sequential clinical and electroretinographic (International Society for Clinical Electrophysiology of Vision standards) evaluations every 6 months. MAIN OUTCOME MEASURES Presence of recognizable retinal and optic atrophy in the presence of abnormal electroretinogram (ERG) and other clinical findings. RESULTS Three children being treated for seizures with vigabatrin showed definite clinical findings of peripheral retinal nerve fiber layer atrophy, with relative sparing of the central or macular portion of the retina and relative nasal optic nerve atrophic changes. Some macular wrinkling was evident in 1 case. Progressive ERG changes showing decreased responses, especially the 30-Hz flicker response, supported the presence of decreased retinal function. CONCLUSIONS A recognizable and characteristic form of peripheral retinal atrophy and nasal or "inverse" optic disc atrophy can occur in a small number of children being treated with vigabatrin. The changes in superficial light reflexes of the retina in children facilitate the clinical recognition of nerve fiber layer atrophy. The macula is relatively spared, although superficial retinal light reflexes indicating wrinkling of the innermost retina suggest early macular toxicity as well. Because these changes are accompanied by electrophysiologic evidence of retinal dysfunction, discontinuation of vigabatrin should be strongly considered.
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Affiliation(s)
- J Raymond Buncic
- Department of Ophthalmology, The Hospital for Sick Children, Toronto, ON, Canada
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Abstract
Visual disturbances are a common side-effect of many antiepileptic drugs. Non-specific retino- and neurotoxic visual abnormalities, that are often reported with over-dosage and prolonged AED use, include diplopia, blurred vision and nystagmus. Some anticonvulsants are associated with specific visual problems that may be related to the mechanistic properties of the drug, and occur even when the drugs are administered within the recommended daily dose. Vigabatrin, a GABA-transaminase inhibitor, has been associated with bilateral concentric visual field loss, electrophysiological changes, central visual function deficits including reduced contrast sensitivity and abnormal colour perception, and morphological alterations of the fundus and retina. Topiramate, a drug that enhances GABAergic transmission, has been associated with cases of acute closed angle glaucoma, while tiagabine, a GABA uptake inhibitor, has been investigated for a potential GABAergic effect on the visual field. Only mild neurotoxic effects have been identified for patients treated with gabapentin, a drug designed as a cyclic analogue of GABA but exhibiting an unknown mechanism while carbamazepine, an inhibitor of voltage-dependent sodium channels, has been linked with abnormal colour perception and reduced contrast sensitivity. The following review outlines the visual disturbances associated with some of the most commonly prescribed anticonvulsants. For each drug, the ocular site of potential damage and the likely mechanism responsible for the adverse visual effects is described.
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Affiliation(s)
- Emma J Roff Hilton
- Neurosciences Research Institute, School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7E7, UK
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Westall CA, Nobile R, Morong S, Buncic JR, Logan WJ, Panton CM. Changes in the electroretinogram resulting from discontinuation of vigabatrin in children. Doc Ophthalmol 2004; 107:299-309. [PMID: 14711162 PMCID: PMC3880365 DOI: 10.1023/b:doop.0000005339.23258.8f] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Electroretinograms (ERGs) have been recorded longitudinally in children before and during treatment with the antiepileptic drug vigabatrin for the past 3.5 years. Vigabatrin induced changes in ERG responses occur in children; the most dramatic changes occur in the oscillatory potentials. The purpose of this study was to identify changes in ERG responses associated with discontinuation of vigabatrin treatment. If vigabatrin-induced changes reverse after discontinuation of the drug we infer that the original change is not an indicator of toxicity. ERG data were analyzed from 17 children who discontinued vigabatrin therapy. The duration of treatment ranged from 5 to 52 months, the age for the first ERG ranged from 6 to 38 months (median 10 months). ERGs were tested using the standard protocol established by the International Society for Clinical Electrophysiology of Vision, with Burian-Allen bipolar contact-lens electrodes. In addition to standard responses we recorded photopic oscillatory potentials (OPs). During vigabatrin treatment OPs show a greater change than other ERG responses, with the early occurring wavelets from the photopic OPs showing the greatest change. With discontinuation of vigabatrin the amplitude of the early wavelets of the photopic OPs increased dramatically compared with amplitudes while taking the drug (paired t-test, p = 0.000075). The scotopic oscillatory potentials also show some recovery. Although changes in oscillatory potentials may occur with vigabatrin toxicity, a large change likely occurs with a non-toxic pharmacological effect of vigabatrin on GABAergic amacrine cells in the inner plexiform layer. Reduction of OPs in children on vigabatrin may not be related to toxicity.
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Affiliation(s)
- Carol A Westall
- Department of Ophthalmology, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
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Abstract
AIMS To report the discovery of a previously unknown form of optic atrophy associated with use of the anti-epileptic drug vigabatrin. METHODS We conducted a retrospective analysis of digitally enhanced ocular fundus photographs, kinetic visual field maps and treatment parameters for 25 patients, who were selected to represent a large spectrum of visual field defects. RESULTS In all, 21 patients (84%) evidenced subtle, diffuse atrophy of the retinal nerve fibre layer, in a pattern accessible to scoring. Atrophy scores correlated with visual field remains and cumulative vigabatrin doses. A pathophysiological model is proposed that involves the lengths of intraocular (unmyelinated) retinal ganglion cell axons. CONCLUSION Optic atrophy attests to the irreversible nature of vigabatrin's visual toxicity. Ocular fundus imaging should prove useful for objectively monitoring vigabatrin-treated subjects for visual toxicity.
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Affiliation(s)
- Lars Frisén
- Institute of Clinical Neuroscience, Sahlgren's Academy at Gothenburg University, SE-413 45 Gothenburg, Sweden.
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39
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Capovilla G, Beccaria F, Montagnini A, Cusmai R, Franzoni E, Moscano F, Coppola G, Carotenuto M, Gobbi G, Seri S, Nabbout R, Vigevano F, Beccaria F, Montagnini A, Coppola G. Short-term nonhormonal and nonsteroid treatment in West syndrome. Epilepsia 2003; 44:1085-8. [PMID: 12887441 DOI: 10.1046/j.1528-1157.2003.55402.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE West syndrome (WS) is considered an age-dependent epileptic encephalopathy and also a particular type of electrical epileptic status. Short-term hormonal or steroid treatment of WS with good efficacy is reported in the literature. The aim of this retrospective multiinstitutional study was to evaluate the early discontinuation of nonhormonal and nonsteroid treatment for WS. METHODS Twenty-two WS cases in which treatment was discontinued after a maximum of 6 months, were collected. Inclusion criteria were the presence of typical EEG hypsarrhythmia (HY) and video-EEG recorded epileptic spasms. Exclusion criteria were the presence of partial seizures or other seizure types before spasm onset. The patients were treated with vigabatrin (VGB) in 19 cases and nitrazepam (NTZ) in three. The dose range was 70-130 mg/kg/day for VGB and 0.7-1.5 mg/kg/day for NTZ. The drug was discontinued if spasms stopped and HY disappeared after a mean treatment period of 5.1 months (range, 3-6 months). All patients underwent repeated and prolonged awake and sleep video-EEG, both before and after drug discontinuation. RESULTS Cryptogenic (15) and symptomatic (seven) WS patients were included. All the symptomatic cases had neonatal hypoxic-ischemic encephalopathy. The mean age at spasm onset was 5.5 months (range, 3-7 months; median, 6). The interval between spasm onset and drug administration ranged from 7 to 90 days (mean, 23 days; median, 20). The interval between drug administration and spasm disappearance ranged from 2 to 11 days (mean, 6 days; median, 6 days). The interval between drug administration and HY disappearance ranged from 3 to 30 days (mean, 9 days; median, 10 days). Drugs were stopped progressively over a 30- to 60-day period. Follow-up ranged from 13 to 50 months (mean, 26 months; median, 22 months). None of our cases showed spasm recurrence. CONCLUSIONS Our data show that successful nonhormonal and nonsteroid treatment can be shortened to a few months without spasm recurrence in patients with cryptogenic or postanoxic WS.
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Affiliation(s)
- Giuseppe Capovilla
- Department of Child Neuropsychiatry, "C Poma" Hospital, Mantova Department of Neurology, Bambino Gesù Children's Hospital, Rome
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40
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Abstract
Childhood epilepsy is a common condition, with an annual incidence of approximately 40 of 100,000 in the first decade of life. Although childhood epilepsy is more likely to remit than epilepsy in adults, the developmental and social impact of epilepsy during childhood may extend beyond the childhood years, affecting the individual's potential in cognitive, emotional and socio-economic arenas. The goal of medical management of childhood epilepsy is seizure freedom, with minimal or no adverse effects. Achievement of this goal is crucial in the effort to minimise the long-term disabilities associated with childhood epilepsy. Pharmacotherapy is a cornerstone of management of childhood epilepsy. This review addresses some of the challenges in treatment of epilepsy, which are unique to childhood, and reviews the newer anticonvulsants available and what is known about their role in childhood epilepsy.
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Affiliation(s)
- Ann M Bergin
- Division of Epilepsy & Clinical Neurophysiology, Department of Neurology, Childrens' Hospital, 300 Longwood Ave, Boston, MA 02115, USA.
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41
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Bialer M, Johannessen SI, Kupferberg HJ, Levy RH, Loiseau P, Perucca E. Progress report on new antiepileptic drugs: a summary of the Sixth Eilat Conference (EILAT VI). Epilepsy Res 2002; 51:31-71. [PMID: 12350382 DOI: 10.1016/s0920-1211(02)00106-7] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The Sixth Eilat Conference on New Antiepileptic Drugs (AEDs) took place in Taormina, Sicily, Italy from 7th to 11th April, 2002. Basic scientists, clinical pharmacologists and neurologists from 27 countries attended the conference, whose main themes included dose-response relationships with conventional and recent AEDs, teratogenic effects of conventional and recent AEDs, update on clinical implications of AED metabolism, prevention of epileptogesis, and seizure aggravation by AEDs. According to tradition, the central part of the conference was devoted to a review of AEDs in development, as well to updates on AEDs, which have been marketed in recent years. This article summarizes the information presented on drugs in preclinical and clinical development, including carabersat (SB-204269), CGX-1007 (Conantokin-G), pregabalin, retigabine (D-23129), safinamide, SPD421 (DP-VPA), SPM 927, talampanel and valrocemide (TV 1901). Updates on fosphenytoin, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, vigabatrin, zonisamide, new formulations of valproic acid, and the antiepileptic vagal stimulator device are also presented.
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Affiliation(s)
- M Bialer
- School of Pharmacy and David R Bloom Centre for Pharmacy, Faculty of Medicine, Ein Karem, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.
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42
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Millichap JG. Test for Vigabatrin-Induced Field Defects in Children. Pediatr Neurol Briefs 2002. [DOI: 10.15844/pedneurbriefs-16-5-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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