Detailed Structure of the Venous Drainage of the Brain: Relevance to Accidental and Non-Accidental Traumatic Head Injuries Seneka Nakagawa, BMedSci Thesis submitted to the University of Nottingham for the degree of Doctor of Philosophy March 2014 Contents Contents ...................................................................................................... i Abstract ................................................................................................... viii Conferences and Peer-reviewed Publications ................................................... ix Acknowledgements ....................................................................................... x List of Definitions and Abbreviations ............................................................... xi List of Figures ........................................................................................... xiv List of Tables ............................................................................................xxiv Chapter 1. Introduction and Literature Review ................................................ 1 1.1. Background ..................................................................................... 1 1.2. Summary of Anatomy of the Meninges and Venous System ............ 2 1.3. Introduction to NAHI and SBS ......................................................... 9 1.4. Introduction to Hypotheses and Theories regarding SDH in NAHI .. 10 1.4.1. Rotational Acceleration of the Head causing Bridging Vein Rupture .............................................................................................. 11 1.4.2. Multiple Acceleration/Deceleration and Whiplash Injuries causing Bridging Vein Damage ........................................................................ 12 1.4.3. Impact-Deceleration Injury and Short Distance Falls ............... 14 1.4.4. Neck and Cervical-Spinal Cord Injury ....................................... 17 1.4.5. Hypoxic-Ischaemic Injury ........................................................ 19 1.4.6. Unified Hypothesis ................................................................... 21 1.4.7. Further Mechanisms ................................................................. 22 1.4.8. Evidence against Bridging Vein Rupture ................................... 22 1.4.9. Intradural Vascular Plexus ....................................................... 24 1.4.10. Chronic Subdural Haemorrhage (CSDH) ................................. 25 1.4.11. Birth-Related SDH .................................................................. 27 1.4.12. Neomembrane Formation ....................................................... 28 1.4.13. Movement of CSF ................................................................... 29 i 1.4.14. Involvement of the Arachnoid Membrane ............................... 29 1.4.15. Involvement of CSF and the Intravascular Plexus .................. 30 1.5. Brief Introduction into Tissue Fixation ............................................ 30 1.5.1. Perfusion Fixation .................................................................... 31 1.5.1.1. Formaldehyde Fixative .......................................................... 31 1.5.2.1. Glutaraldehyde Fixative ......................................................... 31 1.6. Brief History of Resins and Vascular Corrosion Casting (VCC) ........ 32 1.6.1. Delivery of Fluids into the Circulatory System .......................... 33 1.6.2. Vascular Casting ...................................................................... 33 1.7. Introduction to Imaging ................................................................. 34 1.7.1. Imaging of the Intracranial Venous System ............................. 35 1.7.2. Qualitative Analysis ................................................................. 35 1.7.2.1. MRI and CT .......................................................................... 35 1.7.2.2. SEM and TEM ....................................................................... 36 1.7.2.3. Combining MRI and EM in a Clinical Setting.............................. 37 1.7.3. Quantitative Analysis ............................................................... 37 1.7.3.1. Confocal Microscopy .............................................................. 37 1.7.3.2. MicroCT and 3D X-Ray Microscopy (XRM) ................................ 38 1.7.4. Combining Qualitative and Quantitative Analysis Techniques ... 40 1.7.5. Imaging of Intracranial Vessels and Investigating Head Trauma Cases ................................................................................................. 40 1.7.5.1. General Overview ................................................................. 40 1.7.5.2. Investigating Retinal Haemorrhage ......................................... 41 1.7.5.3. Skeletal Surveys ................................................................... 42 1.7.5.4. MRI and CT Scanning ............................................................ 42 1.7.5.5. Discrepancies and Distinguishing Between Accidental and NAHIs 43 1.7.6. Summary, Aims and Objectives ............................................... 44 Chapter 2. Cerebral Microvasculature of the Rat: Resin Casting and SEM ........... 46 2.1. Introduction ................................................................................... 46 ii 2.2. Materials and Methods ................................................................... 47 2.2.1. Methodology for Cardiac Perfusion Fixation and PU4ii Resin Perfusion ............................................................................................ 52 2.2.1.1. Calculation of the Total Blood Volume of a Rat ......................... 52 2.2.1.2. Vascular Resin Casting .......................................................... 55 2.2.2. Tissue Processing ..................................................................... 55 2.2.2.1. Dissection and Decalcification ................................................. 55 2.2.2.2. Maceration and Osmocation ................................................... 55 2.2.2.3. Lyophilisation (Freeze-drying) ................................................ 56 2.2.3. Tissue Analysis ........................................................................ 56 2.2.3.1. Macroscopy .......................................................................... 56 2.2.3.2. Scanning Electron Microscopy (SEM) ....................................... 56 2.2.3.3. Environmental Scanning Electron Microscopy (ESEM) ................ 57 2.2.3.4. Histology and FM Imaging ..................................................... 58 2.2.3.5. Preparation of Histological Specimens ..................................... 59 2.2.3.6. Acquiring Bright Field (BF) and Fluorescence Microscopy (FM) Images ............................................................................................ 61 2.2.3.7. Acquiring Confocal Microscopy (CM) Images ............................ 62 2.2.3.8. MicroCT Imaging of Vascular Casts ......................................... 63 2.2.3.9. Volume Rendering and Approximating Vessel Size from MicroCT Imaging Datasets ............................................................................. 64 2.3. Results ........................................................................................... 65 2.3.1. Vascular Resin Casting and SEM Imaging ................................. 65 2.3.2. Vascular Resin Casting and ESEM Imaging ............................... 67 2.3.2.1. ESEM Imaging of VCCs .......................................................... 67 2.3.2.2. ESEM Imaging of 1mm Coronal Sections of Resin Perfused Brain and Skull ......................................................................................... 86 2.3.3. Histology and Fluorescence Microscopy (FM) Imaging .............. 89 2.3.4. Confocal Microscopy of Resin Perfused Tissue .......................... 91 2.3.5. MicroCT Imaging ...................................................................... 91 iii 2.3.6. Volume Rendering and Approximating Vessel Size from microCT Imaging Datasets ............................................................................... 93 2.4. Discussion ...................................................................................... 94 2.4.1. Intradural and Subdural Vessels .............................................. 95 2.4.2. ESEM Imaging of VCCs ............................................................ 95 Chapter 3. Investigating Venous Anatomy in the Human (Homo sapiens) .......... 98 3.1. Introduction ................................................................................... 98 3.2. Materials and Methods ................................................................... 98 3.2.1. Perfusion Fixation and PU4ii Resin Perfusion of Fresh Cadaveric Material .............................................................................................. 98 3.2.1.1. Calculation of the Cerebral Blood Volume (CBV) of an Adult Human ...................................................................................................... 98 3.2.1.2. Perfusion Fixation and PU4ii Resin Perfusion of Fresh Cadaveric Material ........................................................................................... 99 ........................................................................................................ 100 3.2.2. Gross Dissection of Cadaveric Material ................................... 100 3.2.3. Histological Evaluation of Prefixed and Resin Perfused Cadaveric