A critical analysis of medical opinion evidence in child homicide cases Sharmila Betts B.A. (Hons.), University of Sydney, 1985 M. Psychol., University of Sydney, 1987 A thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in the Faculty of Law, The University of New South Wales (Sydney). i ii iii Acknowledgements No way of thinking or doing, however ancient, can be trusted without proof. Henry David Thoreau I am a Clinical Psychologist practicing since 1987. My time at a tertiary level Child Protection Team at The Sydney Children’s Hospital, Randwick, Australia brought to my attention the pivotal role of medical opinion evidence in establishing how children sustained injuries, which were sometimes fatal. This thesis began in a Department of Psychology, but I transferred to a Law Faculty. Though I am not a lawyer, the thesis endeavours to examine medico-legal and psychological aspects of sudden unexplained infant deaths. It sets itself the task of addressing important questions requiring rigorous and critical analysis to ensure accuracy and justice is achieved. I hope my thesis sheds light on this complex issue. Gary Edmond has been a mentor, guide and staunch critic. I am deeply grateful that he trusted a novice to navigate this perplexing field of inquiry. Emma Cunliffe has provided clarity in an area shrouded in uncertainty. Their patience, support and faith have enabled me to crystalise and formulate my fledgling insights into a dissertation. I am indebted to Natalie Tzovaras, Monique Ross, Katie Poidomani, and Janet Willinge for their administrative support. My husband, Grant, posed the question that started my journey - ‘how do doctors know the injuries were deliberately inflicted?’ Through my many doubts and fears, he iv maintained a trust in my ability to address this question and helped me return time and again to the seemingly overwhelming task before me. Without him the thesis would not have been achieved. His insistence on evidence and proof has shaped my own critical thinking and is the driving force behind my research. My son, Nick, has inspired me to seek truth and justice, both of which he passionately pursues. If I have achieved a modicum of his vision, I have done well. My mother has placed her faith in my abilities well before they were evident. I owe her a debt of gratitude. For these reasons, the thesis is dedicated to them. v Abbreviations AHT Abusive head trauma ALTE Acute or apparent life threatening event ATD Anthropomorphic test device CCD Cerebrocranial disproportion CESDI Confidential Enquiry into Sudden Deaths in Infancy SUDI Sudden Unexplained Deaths in Infancy CONI Care of Next Infant Programme (England) CPR Cardio-pulmonary resuscitation CSF Cerebrospinal fluid CT Computerised axial tomography (also called CAT scan) DAI Diffuse axonal injury EBM Evidence-based medicine HIE Hypoxic ischemic encephalopathy iTBI Inflicted traumatic brain injury ICP Intracranial pressure IDH Intra-dural haemorrhage MCAD Medium-chain acyl-coenzyme A dehydrogenase deficiency MRI Magnetic resonance imaging MSbP Munchausen Syndrome by Proxy NAHI Non-accidental head injury NRC National Research Council PSDH Perinatal subdural haemorrhage RH Retinal haemorrhage vi SBS Shaken baby syndrome SDH Subdural haemorrhage SIDS Sudden infant death syndrome SIS Shaken impact syndrome SUDEP Sudden and unexpected death in epilepsy SUDI Sudden unexplained death in infancy TAI Traumatic axonal injury vii Glossary of Medical Terms Anaemia A deficiency in the number or quality of red blood cells or haemoglobin in the blood. Apnoea Temporary absence or cessation of breathing. Arachnoid mater One of the three meninges covering the brain and spinal cord. It is interposed between the dura and pia mater. It is separated from the pia mater by the subarachnoid space. Artery The blood vessels that carry oxygenated blood from the heart to the body’s tissues. Arterial hypertension Hypertension is high blood pressure, which is the force of blood pushing against arterial walls as it flows through arteries. Asphyxia An extreme reduction in the amount of oxygen in the body with an increased concentration of carbon dioxide leading to loss of consciousness or death. Asphyxia can be induced by choking, drowning, electric shock, injury, or the inhalation of toxic gases. It is a complicated term and used in different ways by different authors in different contexts. Aspiration pneumonia Pneumonia caused by breathing in or aspiration of foreign material into the lungs, usually gastric contents. Asthma A chronic, long-lasting inflammatory disease of the airways. The inflammation causes the airways to spasm and swell periodically causing a narrowing of airways. The individual then needs to wheeze or gasp for air. Autopsy Examination of a cadaver to determine or confirm the mechanical, medical and manner of cause of death and to assist in recreating the circumstances of death. Also called post-mortem or post- mortem examination. Biochemical The chemical composition of a particular living system or biological substance. viii Bridging veins The brain is attached to the skull with bridging or connecting veins. These veins move blood from the brain to the dural sinuses. Capillary One of minute vessels connecting arterioles (artery branch) and venules (small vein joining capillaries to a larger vein), the walls of which act as semi-permeable membrane for the interchange of substances between the blood and tissue fluid. Cardiac Relating to the heart. Dysrhythmias Any abnormality in the rate, sequence or regularity of cardiac activation. Also called cardiac arrythmia. Cerebral oedema Brain swelling caused by increased volume of extra-vascular compartment from the uptake of water in the grey and white matter in the brain. Cerebral haemorrhage Bleeding into the brain. Cerebral venous hypertension High blood pressure in the veins of the brain. Cerebral venous congestion An abnormal accumulation of blood in the veins in the brain. Cerebrocranial disproportion Refers to the swollen oedematous cerebrum requiring a larger space than the semi-rigid infant cranium can provide. Cerebrospinal fluid A clear bodily fluid that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord. The brain ‘floats’ in the fluid, which occupies the space between the arachnoid and pia mater. The fluid constitutes the content of the intra-cerebral ventricles, as well as the central canal of the spinal cord. It acts as a buffer for the cortex (outermost layer of the brain) that provides mechanical and immunological protection to the brain inside the skull. Cerebrum The main part of the brain that occupies the upper part of the cranial cavity. Its two hemispheres are united by the corpus callosum and form the largest part of the central nervous system. ix Coagulopathy A defect in the body's mechanism for blood clotting, causing susceptibility to bleeding. Also called clotting disorder and bleeding disorder. Colic Persistent and unexplained crying in healthy infants aged between 2 weeks and 5 months. Computerised axial tomography An imaging technique using computer-processed X-rays to produce tomographic images (of body sections via penetrating waves) or ‘slices’ of specific areas of the body. Digital geometry processing generates a three-dimensional image of the inside of the body from a large series of two-dimensional X-ray images taken around a single axis of rotation. These cross-sectional images are used for diagnosis and treatment. Congenital viscero-autonomic dysfunction Dysfunction in the viscera – the soft internal organs, especially within the abdominal and thoracic (part between the neck and diaphragm, encased by the ribs) cavities, and the autonomic nervous system – the peripheral nerves that carry brain signals and control involuntary body functions, such as the beating of the heart. Connective tissue disorders Tissue that connects, supports, binds or encloses the structures of the body. Connective tissues are made up of cells embedded in an extracellular matrix and include bones, cartilage, mucous membranes, fat and blood. Disorders in connective tissue include those caused by vitamin deficiencies and depletions. Cranial suture Line of junction between two bones in the cranium. Cranium The components comprising that part of the skull that is a bony enclosure for the brain. Dehydration The loss of water and salts necessary for normal body function. Diffuse axonal injury One of the most common and devastating types of brain injury, in which damage occurs over a more widespread area than in focal x brain injury. It refers to extensive lesions in white matter tracts, is one of the major causes of unconsciousness and persistent vegetative state after head trauma. Diffuse axonal injury is not only caused by trauma and is difficult to distinguish from cerebral anoxia/hypoxia. In cases of trauma, such as shaking, hypoxia/anoxia can be present. However, the distribution of the axonal injury through the brain is different when purely due to trauma compared to hypoxia/anoxia. Diffuse falcine intra-dural haemorrhage Widespread bleeding in the falx, a very thin layer of tissue/fold of dura mater separating the two hemispheres of the brain. Dura mater The outermost of three layers of the meninges surrounding the brain and spinal cord, and is responsible for containing the cerebrospinal fluid. Dural capillary plexus A vascular structure in the form of a network. Encephalopathy Degeneration of brain function