Cerebral Visual Impairment in Children

Cerebral Visual Impairment in Children

Josef Zihl Gordon N. Dutton Cerebral Visual Impairment in Children Visuoperceptive and Visuocognitive Disorders

Josef Zihl LMU Munich Department of Psychology München Germany Gordon N. Dutton Department of Visual Science Glasgow Caledonian University Glasgow UK ISBN 978-3-7091-1814-6 ISBN 978-3-7091-1815-3 (ebook) DOI 10.1007/978-3-7091-1815-3 Springer Wien Heidelberg New York Dordrecht London Library of Congress Control Number: 2014952222 Springer-Verlag Wien 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher's location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Preface Despite the heterogeneity of the umbrella term cerebral visual impairment (CVI) to denote visual dysfunction in early childhood that results from a wide range of developmental disorders and brain injuries, research on CVI and its translation into practice has undergone a remarkable transformation during the last 10 years. Not only are the differences between the developing and the developed brain and the patterns of visual dysfunction better understood, but the concepts concerning functional plasticity, particularly in the developmental phases of the brain, have also been empirically established. This remarkable progress has been possible due to the successful marriage between the so-called basic neuroscience disciplines and clinical neuroscience, including in particular (paediatric) neurology, neuro-ophthalmology and neuropsychology. Basic neuroscience has taken on board clinical knowledge, while clinical research has been guided by fundamental neuroscientific evidence. Consequently, both approaches have benefitted reciprocally and are now in a position to contribute significantly to assessment, diagnostic classification and intervention, founded upon a common evidence-based framework. This book has primarily been written for all those who work with and for children with CVI: ophthalmologists, paediatric neurologists, psychologists, orthoptists, optometrists, occupational therapists, physiotherapists, speech therapists, teachers and many others. Thus, we have in essence chosen an interdisciplinary approach. This is salient because most children with CVI manifest additional functional impairments in the various domains of cognition, speech and language, motor activities, motivation and mood. Therefore, we deemed it appropriate to consider the accompanying nonvisual impairments, so as to ensure that diagnostic assessment is complete and that intervention procedures are tailor-made for the special combination of visual and nonvisual impairment patterns in each affected child. The use of a common professional language is a crucial prerequisite for successful and satisfactory co-operation between the different disciplines involved in the habilitation and education of children with CVI. We therefore have employed a language that is hopefully comprehensible to all professions (the glossary at the end of the book providing additional help). We want to dedicate this book to all the children with CVI who have helped us to understand that their oft-times incomplete and sometimes confusing or even irritating visual worlds are nevertheless interesting and exciting ones that are worth identifying, characterising, explaining and acting upon. v

vi Preface Josef Zihl and Gordon N. Dutton thank the children and their parents for their agreed contributions in Chap. 6 (the anonymised report to parents) and Chap. 9 and Prof. Dr. Siegfried Priglinger for providing material for the latter chapter. Part of this book is based on the German monograph Sehstörungen bei Kindern visuoperzeptive und visuokognitive Störungen bei Kindern mit CVI (Visual disorders in children Visuoperceptive und visuocognitive dysfunction in children with CVI ) by J. Zihl, K. Mendius, S. Schuett and S. Priglinger (Wien and New York, Springer, 2012), while GD wishes to thank Helen Krushave and Nicola McDowell for their major contributions to cases 7 and 8, respectively, in Chap. 9. JZ thanks Katharina Mendius and Susanne Schuett for their help with the literature used in the German monograph. Furthermore, JZ expresses his thanks to Walter Untermarzoner and his family in Villanders (South Tyrol, Italy), for their hospitality and for providing their wonderful alpine hut as a kind of writing office for this book, and to Sepp and Pia, for their generous care with excellent food and wine during his stay in this special retreat. Both authors appreciate the care and support of Katrin Lenhart and Wilma McHugh from Springer in realising the publication of the book. Munich, Germany Glasgow, UK Josef Zihl Gordon N. Dutton

Contents 1 Introduction............................................... 1 2 Development and Neurobiological Foundations of Visual Perception......................................... 11 2.1 Visual and Oculomotor Functions and Their Significance for Visual Perception..................................... 11 2.2 Neurobiological Foundations of Vision...................... 15 2.3 Development of Vision and of Its Neurobiological Foundations... 19 2.3.1 Visual Field..................................... 22 2.3.2 Visual Adaptation................................. 23 2.3.3 Visual Contrast Sensitivity and Visual Acuity........... 24 2.3.4 Colour Vision.................................... 26 2.3.5 Visual Space Perception............................ 27 2.3.6 Form and Object Perception........................ 27 2.3.7 Visual Categorisation, Concept Formation and Constancy................................... 29 2.3.8 Face Perception.................................. 31 2.3.9 Text Processing and Reading........................ 32 2.3.10 Social Perception and Social Behaviour............... 34 2.4 Attention in Vision...................................... 36 2.5 Visual Memory......................................... 37 2.6 Visual-Motor Functions.................................. 38 2.7 Ocular Motor Functions.................................. 39 2.7.1 Accommodation and Convergence................... 39 2.7.2 Fixation........................................ 40 2.7.3 Saccadic Eye Movements.......................... 40 2.7.4 Smooth Pursuit Eye Movements..................... 41 2.7.5 Binocular Eye Movements and Binocular Vision........ 42 2.7.6 Visual Exploration and Visual Search................. 43 2.7.7 Optokinetic Nystagmus (OKN), the Vestibulo-Ocular Reflex (VOR) and Cerebellar Input................... 45 2.7.8 Head Movements and Vision........................ 45 2.7.9 Grasping........................................ 46 2.8 Comments............................................. 46 vii

viii Contents 3 Development of Non-visual Mental Functions and Capacities...... 51 3.1 Attention.............................................. 52 3.2 Learning and Memory.................................... 53 3.3 Executive Functions..................................... 55 3.4 Language.............................................. 57 3.5 Emotions.............................................. 58 3.6 Motivation............................................. 59 Conclusion................................................. 60 4 Visual Disorders............................................ 61 4.1 Preliminary Remarks.................................... 61 4.2 The Concept of CVI (Cerebral Visual Impairment)............. 62 4.3 Visual Disturbances..................................... 67 4.3.1 Visual Field..................................... 71 4.3.2 Visual Acuity, Contrast Sensitivity, Optics and Accommodation.............................. 76 4.3.3 Visual Adaptation................................. 79 4.3.4 Colour Vision.................................... 80 4.3.5 Stereopsis....................................... 80 4.3.6 Perception of Movement........................... 81 4.3.7 Visual Localisation and Visual Direction Perception..... 82 4.3.8 Form Vision, Object and Face Perception.............. 85 4.3.9 Text Processing and Reading........................ 90 4.3.10 Field of Attention................................. 92 4.3.11 The Dorsal/Ventral Stream Dissociation of Visual Processing............................... 97 4.4 Eye Movements......................................... 100 4.4.1 Fixation........................................ 101 4.4.2 Saccadic and Smooth Pursuit Eye Movements; OKN..... 101 4.4.3 Oculomotor Scanning Patterns; Visual Exploration and Visual Search................................. 103 4.4.4 Head Movements................................. 105 4.5 CVI and Aetiology of Brain Injury.......................... 106 4.5.1 Disorders of Brain Development..................... 106 4.5.2 Preterm Birth.................................... 108 4.5.3 Periventricular Leucomalacia (PVL)/Periventricular Brain Injury/White Matter Damage of Immaturity....... 109 4.5.4 Hypoxia........................................ 110 4.5.5 Epilepsy........................................ 110 4.5.6 Other Aetiologies................................. 111 4.5.7 Visual Disorders in Children with Cerebral Palsy (CP).... 113 4.5.8 Acquired in Later Childhood........................ 114 4.5.9 Non-organic ( Functional ) Visual Dysfunction......... 115 5 On the Coexistence of CVI and Mental and Motor Dysfunctions.... 117 5.1 Some Introductory Remarks............................... 117 5.2 Cognition.............................................. 118 5.3 Language and Reading................................... 119

Contents ix 5.4 Emotions and Affective and Social Behaviour................. 120 5.5 Motivation............................................. 120 5.6 Motor Activities........................................ 120 6 Diagnostic Assessment....................................... 123 6.1 Some Preliminary Notes.................................. 123 6.2 The Method of Preferential Looking (PL).................... 125 6.3 Visual Evoked Potentials (VEPs)........................... 127 6.4 Diagnostic Procedures in Children with CVI.................. 128 6.4.1 History Taking to Assist Diagnosis and Guide Management of CVI...................... 129 6.4.2 Systematic Observation of Child s Behaviour........... 155 6.4.3 Assessment of Visual Functions and Capacities......... 155 6.4.4 The Test Battery................................. 167 6.5 Oculomotor Functions................................... 169 6.5.1 Convergence and Accommodation................... 169 6.5.2 Fixation........................................ 169 6.5.3 Saccadic Eye Movements.......................... 170 6.5.4 Pursuit Eye Movements............................ 170 6.5.5 Visual Exploration and Visual Search................. 170 6.6 Writing a Report........................................ 173 6.6.1 Example of a Report to Experts...................... 174 6.6.2 Example of a Report to Parents...................... 175 Conclusion................................................. 179 7 Intervention............................................... 181 7.1 Some Introductory Remarks............................... 181 7.2 Spontaneous Recovery and Spontaneous Adaptation in Children with CVI.................................... 182 7.3 Methodical Considerations in Visual Rehabilitation and Special Early Education in Children with CVI............. 186 7.3.1 Functional Visual Assessment....................... 186 7.3.2 Requirements of Intervention Measures............... 190 7.3.3 Perceptual Learning and the Requisite Cognitive Capacities.............................. 192 7.3.4 Children with CVI Without Additional Cognitive Impairments............................. 194 7.3.5 Children with CVI with Additional Cognitive Impairments............................. 195 7.4 Direct Interventions for the Visual Impairments of CVI......... 197 7.4.1 Visual Field and Field of Attention, Visual Exploration and Visual Search....................... 198 7.4.2 Contrast Vision and Visual Acuity.................... 200 7.4.3 Visual Space Perception and Spatial Orientation......... 201 7.4.4 Colour and Form Vision............................ 204 7.4.5 Object and Face Perception......................... 206 7.4.6 Text Processing and Reading........................ 209

x Contents 7.5 Special Intervention Measures in Children with Severe CVI...... 211 7.6 Adaptive Strategies for the Child and Family for Home, School and Community................................... 212 7.6.1 Adapting to the Needs of the Child................... 212 7.6.2 A Practical Model to Explain the Perceptual Limitations Caused by CVI......................... 212 7.6.3 Explaining Cerebral Visual Impairment to Parents, Caregivers and Teachers............................ 213 7.6.4 Approaches to Adopt for Day-to-Day Living at Home, at School and Out and About........................ 214 7.7 Concluding Remarks..................................... 223 8 Profound Cerebral Visual Impairment......................... 227 8.1 Introduction............................................ 227 8.2 Anatomy and Pathophysiology............................. 227 8.3 Clinical Patterns........................................ 228 8.3.1 Isolated Occipital Injury........................... 228 8.3.2 Generalised Brain Damage......................... 229 8.4 Prognosis.............................................. 230 8.5 Principles of Assessment and Management................... 230 8.5.1 History Taking................................... 230 8.5.2 Assessment of Vision.............................. 230 8.6 Behaviours Associated with CVI........................... 234 8.7 Management........................................... 234 Conclusion................................................. 235 9 Case Reports............................................... 237 9.1 Case 1: Lisa............................................ 238 9.1.1 Medical Diagnoses................................ 238 9.1.2 Developmental Status at the Age of 2 Years (Before Intervention).............................. 238 9.1.3 Intervention Plan and Outcome...................... 240 9.1.4 Developmental Status After 2 Years of Intervention...... 241 9.1.5 Further Aims of Intervention and Special Education...... 242 9.2 Case 2: Barbara......................................... 242 9.2.1 Medical Diagnoses................................ 242 9.2.2 Status of Development at the Age of 7 Months (Before Intervention).............................. 242 9.2.3 Visual Intervention Programme...................... 244 9.2.4 Developmental Status at the Age 6 Years (After Intervention)............................... 245 9.3 Case 3: Anna........................................... 246 9.3.1 Medical Diagnoses................................ 246 9.3.2 Visual Intervention Programme...................... 248 9.3.3 Visual Stimulus Materials and Task Conditions......... 248 9.3.4 Visual Discrimination and Identification............... 249

Contents xi 9.3.5 Further Interventions.............................. 249 9.3.6 First Phase of Treatment and Outcome................ 250 9.3.7 Visual Assessment................................ 250 9.3.8 Second Phase of Visual Intervention and Outcome....... 250 9.3.9 Summary and Comment........................... 256 9.4 Case 4: Florian......................................... 256 9.4.1 Medical Diagnoses................................ 256 9.4.2 Intervention Aims and Programme................... 258 9.4.3 Further Intervention Programme as Special Preparation for Occupational Integration........................ 261 9.4.4 Summary and Comments........................... 265 9.5 Case 5: Sarah........................................... 267 9.5.1 Medical Diagnoses................................ 267 9.5.2 Visual Assessment at 20 Months After Surgical Intervention (Age: 11 Years)........................ 267 9.5.3 Intervention and Outcome.......................... 268 9.5.4 Comment....................................... 270 9.6 Case 6: Paul............................................ 271 9.6.1 Medical Diagnoses................................ 271 9.6.2 Intervention and Outcome.......................... 271 9.6.3 Comment....................................... 272 9.7 Case 7: Ben............................................ 273 9.7.1 Medical Diagnoses................................ 273 9.7.2 Introduction..................................... 274 9.7.3 History from Ben s Mother (9 March 2012)............ 274 9.7.4 Intervention and Outcome.......................... 275 9.7.5 Progress Report: 19 March 2012 (Written by Ben s Mother).......................... 276 9.7.6 Follow-Up...................................... 278 9.7.7 Conclusion...................................... 278 9.8 Case 8: Nicola.......................................... 278 9.8.1 Medical Diagnoses................................ 278 9.8.2 Introduction..................................... 278 9.8.3 Patient Autobiography............................. 279 9.8.4 Comment....................................... 281 Erratum..................................................... E1 Glossary..................................................... 283 References................................................. 301 Index........................................................ 335