The epidemiology of brain arteriovenous malformations in adults Rustam Al-Shahi Doctor of Philosophy University of Edinburgh 2005 Preface Contents TABLE OF TABLES............................................................................................ 14 TABLE OF FIGURES.......................................................................................... 16 PREFACE .............................................................................................................20 ACKNOWLEDGEMENTS..................................................................................23 DECLARATION ..................................................................................................25 AWARDS ENABLING AND RESULTING FROM THIS THESIS .................26 PUBLICATIONS AND PRESENTATIONS ARISING FROM WORK ASSOCIATED WITH THIS THESIS .................................................................27 ABBREVIATIONS...............................................................................................32 ABSTRACT...........................................................................................................33 SECTION 1: BACKGROUND TO THE THESIS CHAPTER 1. INTRODUCTION.....................................................................36 1.1 EARLY DESCRIPTIONS OF BRAIN ARTERIOVENOUS MALFORMATIONS ............37 1.2 THE CLASSIFICATION OF BRAIN ARTERIOVENOUS MALFORMATIONS WITHIN THE SPECTRUM OF INTRACRANIAL VASCULAR MALFORMATIONS............................38 1.2.1 EARLY CLASSIFICATION SCHEMES...............................................................................38 1.2.2 CONTEMPORARY CLASSIFICATION..............................................................................39 1.3 BRAIN ARTERIOVENOUS MALFORMATIONS ....................................................39 1.3.1 MORPHOLOGY ...............................................................................................................39 1.3.2 NOMENCLATURE ...........................................................................................................40 1.3.3 RADIOLOGICAL FEATURES...........................................................................................41 1.3.3.1 Differentiating a brain AVM from normal brain and other pathologies...........41 1.3.3.2 Detecting a brain AVM underlying intracranial haemorrhage.............................42 1.3.3.3 Brain AVM angioarchitecture...................................................................................43 1.3.4 BURDEN ..........................................................................................................................44 1.3.4.1 Frequency....................................................................................................................44 1.3.4.2 Prognosis.....................................................................................................................44 1.3.5 TREATMENT ...................................................................................................................44 2 Preface 1.3.6 AETIOLOGY....................................................................................................................45 1.4 AIMS OF THIS THESIS......................................................................................46 CHAPTER 2. SYSTEMATIC REVIEW OF STUDIES OF THE FREQUENCY, CLINICAL PRESENTATION AND PROGNOSIS OF BRAIN ARTERIOVENOUS MALFORMATIONS.........................................................55 2.1 INTRODUCTION .............................................................................................56 2.2 METHODS ......................................................................................................56 2.2.1 LITERATURE SEARCH ....................................................................................................56 2.2.2 CRITICAL APPRAISAL .....................................................................................................57 2.2.2.1 Incidence and prevalence studies.............................................................................58 2.2.2.2 Studies of clinical presentation.................................................................................58 2.2.2.3 Studies of prognosis...................................................................................................58 2.3 RESULTS ........................................................................................................ 61 2.3.1 FREQUENCY ...................................................................................................................61 2.3.1.1 Incidence in unselected populations .......................................................................61 2.3.1.2 Prevalence....................................................................................................................62 2.3.2 CLINICAL PRESENTATION ............................................................................................67 2.3.2.1 How do brain AVMs present clinically? .................................................................67 2.3.2.2 Which characteristics of brain AVMs are associated with the different modes of presentation? ..........................................................................................................68 2.3.3 PROGNOSIS.....................................................................................................................74 2.3.3.1 Methodological problems with studies of brain AVM prognosis.......................74 2.3.3.2 What is the risk of death?..........................................................................................76 2.3.3.3 What is the risk of developing intracranial haemorrhage? ...................................76 2.3.3.4 What is the risk of developing seizures?.................................................................79 2.3.3.5 Pregnancy ....................................................................................................................79 2.3.3.6 Hereditary haemorrhagic telangiectasia...................................................................80 2.4 SUMMARY.......................................................................................................80 2.5 DISCUSSION ................................................................................................... 81 3 Preface SECTION 2: THE SCOTTISH INTRACRANIAL VASCULAR MALFORMATION STUDY (SIVMS) - METHODS AND DESIGN CHAPTER 3. METHODS OF A POPULATION-BASED DISEASE REGISTER FOR ADULTS WITH INTRACRANIAL VASCULAR MALFORMATIONS ............................................................................................95 3.1 INTRODUCTION .............................................................................................97 3.2 STUDY DESIGN AND PROCESS .........................................................................97 3.2.1 SIVMS INCLUSION CRITERIA.......................................................................................97 3.2.2 SIVMS EXCLUSION CRITERIA ......................................................................................98 3.2.3 DIAGNOSTIC CRITERIA SPECIFICALLY FOR BRAIN AVMS IN SIVMS .....................98 3.2.3.1 Morphological definition...........................................................................................99 3.2.3.2 Pathological definition...............................................................................................99 3.2.3.3 Radiological diagnostic criteria.................................................................................99 3.2.3.4 Certainty ......................................................................................................................99 3.2.3.5 Date of diagnosis......................................................................................................101 3.2.4 STUDY SETTING ...........................................................................................................101 3.2.4.1 Demographics of Scotland .....................................................................................101 3.2.4.2 The Scottish health service .....................................................................................102 3.2.5 ETHICAL APPROVAL ....................................................................................................102 3.2.6 SOURCES OF CASE ASCERTAINMENT .........................................................................103 3.2.6.1 Collaborative neuroscience network .....................................................................103 3.2.6.2 General practitioners ...............................................................................................103 3.2.6.3 Centralised coding of hospital discharge data and death certificates................104 3.2.7 NOTIFICATION.............................................................................................................104 3.2.8 RECRUITMENT..............................................................................................................105 3.2.9 COLLECTION OF STUDY MATERIALS DURING RECRUITMENT ...............................106 3.2.9.1 Medical records.........................................................................................................106 3.2.9.2 Diagnostic brain imaging ........................................................................................107 3.2.9.3 Patient questionnaire ...............................................................................................107 3.2.10 COLLECTION OF STUDY