Cerebral Visual Impairment Research Articles

Neurological and Visual Outcomes in Infants and Toddlers Following Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy

BackgroundThe majority of studies have investigated neurodevelopmental outcomes, whereas visual impairment is less explored in children with a history of neonatal (hypoxic-ischemic) encephalopathy. Our aim was to perform a detailed neurological and visual assessment and also to investigate the presence of cerebral visual impairment in infants and toddlers with neonatal encephalopathy. MethodsThirty participants with a history of neonatal encephalopathy, who had been hospitalized for therapeutic hypothermia, underwent a detailed neurological examination at age five to 36 months. Age-matched, 30 healthy children were also enrolled as a control group. All children in the study and control groups received neurological and a comprehensive ophthalmologic examination, including visual field and visual acuity. Presence of cerebral visual impairment was also evaluated clinically. ResultsRates of cerebral palsy, severe motor impairment, cognitive impairment, epilepsy, and cerebral visual impairment were found to be 20%, 10%, 15.3%, 10%, and 20%, respectively. When compared with healthy controls, oculomotor functions, pupillary light response, refractive parameters, anterior/posterior segment examinations, ocular visual impairment rates, and last, visual acuities were found similar. However, we found a statistically significant increase in visual field defects in our study group. ConclusionsIt could be better to perform a comprehensive ophthalmologic examination including visual field, visual acuity, and oculomotor functions by a pediatric ophthalmologist to accurately diagnose neurovisual deficits in infants following therapeutic hypothermia. Early identification and rehabilitation of the visual deficits might improve the neurodevelopment in these children.

Evaluating the Quantity and Quality of Health Economic Literature in Blinding Childhood Disorders: A Systematic Literature Review.

Evidence on the socioeconomic burden associated with childhood visual impairment, severe visual impairment and blindness (VI/SVI/BL) is needed to inform economic evaluations of existing and emerging interventions aimed at protecting or improving vision. This study aimed to evaluate the quantity and quality of literature on resource use and/or costs associated with childhood VI/SVI/BL disorders. PubMed, Web of Science (Ovid), the National Health Service (NHS) Economic Evaluation Database and grey literature were searched in November 2020. The PubMed search was rerun in February 2022. Original articles reporting unique estimates of resource use or cost data on conditions resulting in bilateral VI/SVI/BL were eligible for data extraction. Quality assessment (QA) was undertaken using the Drummond checklist adapted for cost-of-illness (COI) studies. We identified 31 eligible articles, 27 from the peer-reviewed literature and four from the grey literature. Two reported on resource use, and 29 reported on costs. Cerebral visual impairment and optic nerve disorders were not examined in any included studies, whereas retinopathy of prematurity was the most frequently examined condition. The quality of studies varied, with economic evaluations having higher mean QA scores (82%) compared to COI studies (77%). Deficiencies in reporting were seen, particularly in the clinical definitions of conditions in economic evaluations and a lack of discounting and sensitivity analyses in COI studies. There is sparse literature on resource use or costs associated with childhood visual impairment disorders. The first step in addressing this important evidence gap is to ensure core visual impairment outcomes are measured in future randomised control trials of interventions as well as cohort studies and are reported as a discrete health outcome.

Validation of the Austin Assessment: A screening tool for cerebral visual impairment related visual issues.

Cerebral visual impairment is the most common cause of vision impairment affecting children in the economically developed world with a prevalence rate of approximately 3.4%. Currently there are limited options for screening for cerebral visual impairment, resulting in many children going undiagnosed, especially those that have normal visual acuity. The aim of this research was to validate an iPad App called the Austin Assessment, which was developed as a potential screening tool for cerebral visual impairment related visual issues. The research involved three separate phases: (1) creating a database of normative ranges for children aged 5-18 across the different variables of the Austin Assessment, (2) using the Austin Assessment to screen children aged 5-13 to assess the effectiveness of the Austin Assessment as a screening tool for CVI related visual issues, and (3) conducting specific validation research assessing children using the Austin Assessment and an already validated visual search tool. Each phase used different quantitative research methodologies to help show the effectiveness of the Austin Assessment as a screening tool for cerebral visual impairment related visual issues. From phase one of the research, thresholds were established for three variables of the Austin Assessment for the age groupings of 5-8, 9-12 and 13-18. If a child meets one of these thresholds this indicates further assessment is required to determine if they do in fact have cerebral visual impairment related visual issues. Phase two identified 17 children out of 270 who had clinical findings indicating visual issues; potentially indicative of CVI; investigation into the nature of these visual issues is ongoing. Phase three found that the Austin Assessment has moderate diagnostic value for each age group, with good sensitivity and specificity, making it effective at distinguishing those children who have visual issues from those who have typical vision. Further investigation is needed to confirm this initial validation.

Occupational Therapy Assessments of Cortical or Cerebral Visual Impairment: A Systematic Review.

Cortical or cerebral visual impairment (CVI), a leading cause of visual dysfunction in children across the globe, can result in delayed development of fine and gross motor skills, functional mobility, and socialization, which affects all areas of occupation. No assessments are recommended for occupational therapy practitioners working with children with CVI. To appraise the measurement properties and clinical utility of CVI assessments appropriate for use by occupational therapy practitioners. MEDLINE via PubMed, Scopus, and Web of Science. We followed the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines for systematic reviews of patient-reported outcome measures for relevant studies. A total of 590 records yielded 15 studies of the measurement properties of 12 assessment tools, 8 patient-reported outcome measures and 4 clinician-reported or performance-based outcome measures. We report on the quality of measurement properties of 10 of the 12 outcome measures. None had high-quality evidence of content validity, structural validity, or test-retest reliability. Most had indeterminate internal consistency as a result of a lack of confirmatory factor analysis. Three instruments demonstrated high quality and sufficient construct validity. On the basis of the COSMIN guidelines, all 12 outcome measures have the potential to be recommended but require further study before definitive recommendations can be made. What This Article Adds: This is the first systematic review of assessments of CVI feasible for use by occupational therapy practitioners. High-quality studies of measurement properties are lacking. Further examination of the measurement properties of outcome measures is required.

A Case Study on Cerebral Visual Impairment, Reading, and Braille

A Case Study on Cerebral Visual Impairment, Reading, and Braille

The relation between visual orienting functions, visual perception, and functional vision in children with (suspected) cerebral visual impairment

BackgroundBrain-based impairments in visual perception (VP), termed cerebral visual impairment (CVI), are heterogeneous. AimsTo investigate relations between functional vision and (1) visual orienting functions (VOF) and (2) VP. Methods and proceduresForty-four children (Males = 20; Mean age = 9y11m) with (suspected) CVI were tested with an adapted virtual toy box (vTB) paradigm (eye tracking visual search task (VST) and a recognition/memory task), VP tests, a preferential looking eye tracking (PL-ET) paradigm, and the Flemish cerebral visual impairment questionnaire. Relations were tested with Spearman correlations. Outcomes and resultsFunctional vision was related to VOF and VP. Children who performed poorly on the VST performed worse on the PL-ET paradigm (r success rate = 0.508–0.654; r reaction time (to fixation) = 0.327–0.633; r fixation duration = 0.532; r gaze fixation area/error = 0.565). Faster VST reaction time was related to higher recognition/memory task accuracy (r = −0.385) and better object/picture recognition (r = −0.371). Higher accuracy in the recognition/memory task was related to better object and face processing (r = −0.539), less visual (dis)interest (r = −0.380), and better clutter and distance viewing (r = −0.353). Conclusions and implicationsIn CVI, VOF, VP, and functional vision are interlinked, and when one is impaired, it negatively affects the others. Hence, quantitatively profiling basic functioning, higher-order and daily life abilities is crucial.

Childhood cerebral visual impairment subtype classification based on an extensive versus a limited test battery.

To classify CVI subtypes and compare the added value of an extensive test battery over a limited test battery in subtype classification of cerebral visual impairment (CVI) in children. Seventy-five children with a clinical diagnosis of CVI (median [IQR] age: 9 [7-12] years) were identified from the medical records. The extensive test battery included visual acuity, contrast sensitivity, ocular alignment, eye movement analysis, visual field analysis, optic nerve head evaluation, and evaluation of visual perception. The limited test battery included visual acuity, contrast sensitivity, ocular alignment, and evaluation of visual perception. Principal component analysis (PCA) followed by cluster analysis was done, for both test batteries separately, to determine the optimum subtype classification for CVI. Fifty-one participants with an extensive test battery with mild to moderate visual impairment were included in the main analysis. This resulted in four CVI subtypes for the extensive test battery (subtle characteristics, higher-level visual function deficits, lower-level visual function deficits, and higher- and lower- level visual function deficits) and three CVI subtypes for the limited test battery (subtle characteristics, higher-level visual function deficits, and higher- and lower- level visual function deficits). There were significant differences between the subtypes for 9 out of 10 measures of the extensive and all 4 measures of the limited test battery (p < 0.05). The subtle characteristics subtype (extensive n = 19, limited n = 15) showed near normal lower and higher-level visual functions in both test batteries. The higher-level visual function deficits subtype (extensive n = 18, limited n = 24) showed near normal visual acuity combined with significant visual perceptual deficits in both test batteries; accompanied by visual pathways defects and abnormal eye movement behavior in the extensive test battery. The higher- and lower- level visual function deficits subtype (extensive n = 4, limited n = 12) showed both higher and lower-level visual function deficits in both test batteries, but application of the extensive test battery revealed additional visual pathways defects and abnormal eye movement behavior. The lower-level visual function deficits CVI subtype (extensive n = 10) was a new subtype identified by the extensive test battery. This subtype showed lower-level visual function deficits together with abnormal eye movement measures. This data-driven study has provided meaningful CVI subtype classifications based on the outcomes of various key functional and structural measures in CVI diagnosis. Comparison of the extensive test battery to the limited test battery revealed the added value of an extensive test battery in classifying CVI. The outcomes of this study, therefore, have provided a new direction in the area of CVI classification.

CPD: An introduction to cerebral visual impairment in children 4

In the final part of this series looking at an important cause of visual impairment in children, Cirta Tooth outlines how children with cerebral visual impairment can be supported

Australian children with cerebral visual impairment: using what we know now to improve future approaches

ABSTRACT Purpose Little has been reported on Australian children with Cerebral Vision Impairment (CVI). This paper aims to present the outcome of an audit focussed on children with the primary diagnosis of CVI, using findings from the Australian Childhood Vision Impairment Register (ACVIR). Methods Records on 132 children (49% girls, 51% boys) from ACVIR data gathered from both the child’s parent/guardian and their eye health professional were reviewed. The child’s demographics, level of vision impairment, birth history, diagnostic journey, secondary ocular diagnoses, comorbidities and low vision support were analyzed. Several correlations were investigated using a Kendall’s tau-b analysis including the relationship between vision and age of diagnosis; level of vision and developmental delay; and age of suspicion of visual impairment and age of diagnosis. Results The most common level of visual impairment was blindness (39%), and most children were suspected and diagnosed of visual impairment in the first 6 months of life. The majority of children were born full term (72%), weighing >2000gms (84%). Nearly half of the cohort of children (48%) had a secondary ocular diagnosis with 44% having nystagmus. The majority of children (80%) had additional health problems, and 85% of children had additional disabilities, with 79% having developmental delay. Conclusion While the findings of this audit cannot be generalized to a wider population of Australian children with CVI, the outcome encourages continued discussion on CVI, to explore comprehensive assessment approaches which facilitate timely and accurate diagnosis.

Toward Removing Barriers in the Evaluation, Diagnosis, and Care of Individuals With Cerebral Visual Impairments

Cerebral visual impairment (CVI) is a leading cause of pediatric visual impairment worldwide. Despite the ramifications on multiple developmental domains and quality of life factors, substantial barriers remain for evaluation, diagnosis, treatment, and education of this growing population of children and adults. At the root is a lack of consensus on the definition and diagnostic criteria of CVI and a narrow ocular/acuity-based classification of visual impairment. This article covers four main issues that need to be urgently addressed to make strides toward removing current barriers. These challenges highlight the need for policy change at multiple levels to help ensure that individuals with CVI will have access to appropriate (re)habilitation and education services regardless of their acuity or visual function. Suggested solutions include the implementation of a globally accepted definition of CVI and increased multidisciplinary training programs. These will support international efforts to develop and implement quantitative interdisciplinary assessment methods, identify meaningful and effective intervention approaches, and monitor long-term outcomes for those with CVI. Additionally, sensitive and specific markers can be identified for differentiating CVI from other related developmental conditions, such as autism spectrum disorder and developmental coordination disorder. Ultimately, these proposed changes will lead toward improved quality of life for individuals with CVI and their caregivers.

Cerebral visual impairment and effect of phase-wise stimulation strategies-An interim analysis.

Cerebral visual impairment (CVI) is an overarching term, defined as a brain-based visual impairment with onset in childhood, unexplained by an ocular disorder and associated with unique visual and behavioral characteristics. Good vision and awareness of visual function in a child are highly essential as neuroplasticity is maximum in the first three years of life and response to intervention is utmost in this period. Awareness is lacking regarding CVI, and the diagnosis is largely missed. This can be easily addressed if a structured approach is employed. This study aims to evaluate the etiology and radiological correlation with the severity of CVI and outcome after structured intervention in children with CVI. Prospective-interventional study. Children attending the Child Development Centre (CDC) of a tertiary care hospital in North Karnataka and diagnosed with CVI in the age group of six months to 12 years and meeting the sampling criteria were screened and enrolled consecutively after obtaining parental consent/assent. Statistical analysis used is nonparametric test with SPSS software. Age showed a significant association with the phase of CVI. Perinatal insult was associated significantly with the severity of CVI. Magnetic resonance imaging (MRI) findings did not hamper the recovery of CVI. Enrolment in early intervention programs tailored according to child's specific needs should be encouraged, with stress on ophthalmic screening of preterm and high-risk babies with perinatal hypoxia and history of convulsions, as early as six months.

Current perspective: Cerebral visual impairment-The impending doom.

Cerebral visual impairment (CVI) has emerged as an important cause of morbidity in young children. CVI children often have a large number of visual symptoms along with motor abnormalities. It is the need of the hour to build an integrated approach towards their management. This article aimed to provide a comprehensive view of the manifestations, evaluation, and management of children with CVI.

CDKL5 deficiency disorder and other infantile-onset genetic epilepsies.

To differentiate phenotypic features of individuals with CDKL5 deficiency disorder (CDD) from those of individuals with other infantile-onset epilepsies. We performed a retrospective cohort study and ascertained individuals with CDD and comparison individuals with infantile-onset epilepsy who had epilepsy gene panel testing. We reviewed records, updated variant classifications, and compared phenotypic features. Wilcoxon rank-sum tests and χ2 or Fisher's exact tests were performed for between-cohort comparisons. We identified 137 individuals with CDD (110 females, 80.3%; median age at last follow-up 3 year 11 months) and 313 individuals with infantile-onset epilepsies (156 females, 49.8%; median age at last follow-up 5 years 2 months; 35% with genetic diagnosis). Features reported significantly more frequently in the CDD group than in the comparison cohort included developmental and epileptic encephalopathy (81% vs 66%), treatment-resistant epilepsy (95% vs 71%), sequential seizures (46% vs 6%), epileptic spasms (66% vs 42%, with hypsarrhythmia in 30% vs 48%), regression (52% vs 29%), evolution to Lennox-Gastaut syndrome (23% vs 5%), diffuse hypotonia (72% vs 36%), stereotypies (69% vs 11%), paroxysmal movement disorders (29% vs 17%), cerebral visual impairment (94% vs 28%), and failure to thrive (38% vs 22%). CDD, compared with other suspected or confirmed genetic epilepsies presenting in the first year of life, is more often characterized by a combination of treatment-resistant epilepsy, developmental and epileptic encephalopathy, sequential seizures, spasms without hypsarrhythmia, diffuse hypotonia, paroxysmal movement disorders, cerebral visual impairment, and failure to thrive. Defining core phenotypic characteristics will improve precision diagnosis and treatment.

Prospective cohort study of neurodevelopmental outcomes following extreme neonatal hyperbilirubinaemia in Australia.

This study aimed to establish the incidence and nature of neurodevelopmental outcomes following extreme neonatal hyperbilirubinaemia in an Australian cohort. A prospective cohort study of neurodevelopmental outcomes up to 3 years of age of infants born between 2010 and 2013 at ≥34 weeks gestation, with total serum bilirubin ≥450 μmol/L and/or clinical signs of acute bilirubin encephalopathy. Outcome measures comprised neurological examination, Bayley Scales of Infant and Toddler Development, 3rd edition and Ages and Stages Questionnaire, 3rd edition. The Australian estimated incidence of kernicterus is 0.35 per 100 000 live births. Within the follow-up cohort of 26, three children have clinical neurodevelopmental impairment: one has gross motor function classification system level 4 cerebral palsy, audiological deficiency and visual impairment; the second has gross motor function classification system level 1 cerebral palsy and the third has global developmental delay with autism spectrum disorder. Mean Bayley Scales of Infant and Toddler Development, 3rd edition scores were: cognition 10.3 (SD 1.5), receptive communication 9.4 (SD 1.8), expressive communication 9.2 (SD 2.4), fine motor 10.4 (SD 2.6) and gross motor 9.2 (SD 2.3). The Australian national rate of kernicterus compares favourably with global estimates. Future preventative strategies in this context include universal neonatal hyperbilirubinaemia assessment and mandated adverse outcome reporting and investigation.

CPD: An introduction to cerebral visual impairment in children 3

In the third of a four part series looking at an important cause of visual impairment in children, Cirta Tooth outlines how CVI affects children’s development (C???? suitable for logging as one distance learning CPD point for optometrists and dispensing opticians)

Altered neural oscillations underlying visuospatial processing in cerebral visual impairment.

Visuospatial processing deficits are commonly observed in individuals with cerebral visual impairment, even in cases where visual acuity and visual field functions are intact. Cerebral visual impairment is a brain-based visual disorder associated with the maldevelopment of central visual pathways and structures. However, the neurophysiological basis underlying higher-order perceptual impairments in this condition has not been clearly identified, which in turn poses limits on developing rehabilitative interventions. Using combined eye tracking and EEG recordings, we assessed the profile and performance of visual search on a naturalistic virtual reality-based task. Participants with cerebral visual impairment and controls with neurotypical development were instructed to search, locate and fixate on a specific target placed among surrounding distractors at two levels of task difficulty. We analysed evoked (phase-locked) and induced (non-phase-locked) components of broadband (4-55 Hz) neural oscillations to uncover the neurophysiological basis of visuospatial processing. We found that visual search performance in cerebral visual impairment was impaired compared to controls (as indexed by outcomes of success rate, reaction time and gaze error). Analysis of neural oscillations revealed markedly reduced early-onset evoked theta [4-6 Hz] activity (within 0.5 s) regardless of task difficulty. Moreover, while induced alpha activity increased with task difficulty in controls, this modulation was absent in the cerebral visual impairment group identifying a potential neural correlate related to deficits with visual search and distractor suppression. Finally, cerebral visual impairment participants also showed a sustained induced gamma response [30-45 Hz]. We conclude that impaired visual search performance in cerebral visual impairment is associated with substantial alterations across a wide range of neural oscillation frequencies. This includes both evoked and induced components suggesting the involvement of feedforward and feedback processing as well as local and distributed levels of neural processing.

CPD: An Introduction to Cerebral Visual Impairment in Children 2

In the second of a four part series looking at an important cause of visual impairment in children, Cirta Tooth outlines how to diagnose cerebral visual impairment

Commentary: Profiling Children With Cerebral Visual Impairment (CVI) Using Multiple Methods of Assessment to Aid in Differential Diagnosis

PROFILING CHILDREN WITH CEREBRAL VISUAL IMPAIRMENT USING MULTIPLE METHODS OF ASSESSMENT TO AID IN DIFFERENTIAL DIAGNOSIS: Amanda H. Lueck , Gordon N. Dutton , Sylvie Chokron Seminars in Pediatric Neurology Volume 31, October 2019, Pages 5-14 Cerebral (cortical) visual impairment (CVI), the primary cause of visual impairment in chil dren in high-income countries, is increasing globally due to improved life-saving measures for premature and full-term infants. Yet the consequences of this condition are only begin ning to be understood and addressed. According to the topography, site, and the extent of the pathology, the deficit may variably concern central visual functions, visual field, percep tion of movement, visual analysis, visual exploration, attention, or visual memory, as well as visual guidance of movement. Each affected child has a unique clinical picture, which needs to be identified and individually profiled. This is probably the underlying reason that CVI is commonly underdiagnosed or misdiagnosed, especially in children, and, as a consequence, the full range of potential behavioral outcomes are not identified and adequately addressed. The present paper shows how the use of multiple methods of assessment can improve understanding of children with CVI.

The impact of cerebral visual impairment on school related competences in elementary school children

The impact of cerebral visual impairment on school related competences in elementary school children

NEUROPLASTICITY IN CEREBRAL VISUAL IMPAIRMENT

Introduction. The field of pediatric stroke has developed rapidly and has reached the stage where focused funding prioritization is required to make further advances including understanding mechanisms and optimal treatments. The existence of highly motivated and collaborative researchers in this field provides tremendous potential for leveraging research productivity. In recent years, research has been expanding in the direction of studying central hemodynamics, general and local intracerebral circulation, as well as orbital and intraocular hemodynamics when studying the dynamics of cerebral visual impairment (CVI) in children with pre- and perinatal encephalopathy. The aim of the study was studying the mechanisms of the relationship between neuroplasticity and cerebral visual impairment at the recovery stages of intracranial hemodynamic and liquor dynamic disturbances in children with NE. Materials and methods. Over the past 10 years, out of 3,500 children aged from 3 months to 6 years examined by us, with the help and cooperation of the children's neurological hospital, the Republican Perinatal Center and the Research Institute of Pediatrics, 1,500 children were diagnosed with acute cerebrovascular accident in the neonatal period of life. Homeostasis indicators-catecholamines in the blood, excretion in the urine, the sugar and cortisol in the blood, electrolytes in plasma and erythrocytes. NSG, MRI, CDU. The reactivity of BP, of the pulse and respiration to vegetotropic drugs and PA.EEG (sleep rhythm, emotional and motor activity) Results. It has been proven that the decisive mechanisms of recovery options depend on the orientation of the hypothalamic-pituitary relationship and the nature of homeostatic aberrations. The overwhelming majority of these children have experienced catecholamine excite dumping syndrome over these long years and had a clinical picture of both cerebral pathology and CVI. By compiling histograms, it was possible to establish that the effect of cholinergic mechanisms on general hemodynamics was less pronounced than on intraorbital blood circulation. In other words, the assessment of hemodynamic responsiveness to the stimulus revealed a more significant fluctuation in the index of intracranial rather than general hemodynamics. Conclusion. Analysis of variance proves that the stability of the mean dynamic blood pressure is one of the leading mechanisms for stabilization of adaptive homeostatic neuroplasticity of the CNS and visual analyzer.