FORENSIC ASPECTS OF HYPOGLYCAEMIA FORENSIC ASPECTS OF HYPOGLYCAEMIA Vincent Marks DM, FRCP, FRCPath, MAE University of Surrey Surrey, UK CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2019 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Printed on acid-free paper International Standard Book Number-13: 978-0-367-14034-2 (Hardback) 978-1-138-05569-8 (Paperback) This book contains information obtained from authentic and highly regarded sources. While all rea- sonable efforts have been made to publish reliable data and information, neither the author[s] nor the publisher can accept any legal responsibility or liability for any errors or omissions that may be made. The publishers wish to make clear that any views or opinions expressed in this book by individual edi- tors, authors or contributors are personal to them and do not necessarily reflect the views/opinions of the publishers. The information or guidance contained in this book is intended for use by medical, scientific or health-care professionals and is provided strictly as a supplement to the medical or other professional’s own judgement, their knowledge of the patient’s medical history, relevant manufactur- er’s instructions and the appropriate best practice guidelines. Because of the rapid advances in medi- cal science, any information or advice on dosages, procedures or diagnoses should be independently verified. The reader is strongly urged to consult the relevant national drug formulary and the drug companies’ and device or material manufacturers’ printed instructions, and their websites, before administering or utilizing any of the drugs, devices or materials mentioned in this book. This book does not indicate whether a particular treatment is appropriate or suitable for a particular individual. Ultimately it is the sole responsibility of the medical professional to make his or her own professional judgements, so as to advise and treat patients appropriately. The authors and publishers have also attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright mate- rial has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information stor- age or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copy- right.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that pro- vides licenses and registration for a variety of users. For organizations that have been granted a photo- copy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com CONTENTS Preface vii About the Author xi Introduction xiii Acknowledgments xix 1 The Control of Blood Glucose in Health and Disease: Hypoglycaemia 1 2 Petty Crime 27 3 Violence and Aggression 49 4 Accident and Negligence 67 5 Spontaneous (or Non-Iatrogenic) Hypoglycaemia 97 6 Driving Offences 119 7 Hypoglycaemia from Drugs including Insulin and Sulphonylureas 147 8 Forensic Investigation of Hypoglycaemia 175 9 Factitious Hypoglycaemia and Suicide 227 10 Murder; Single Individuals 261 11 Munchausen by Proxy: Infanticide and Murder of Children 293 vi contents 12 Murder and Attempted Murder with Insulin by Carers 321 13 Confessions 347 14 Frequently Asked Questions 359 15 Expert Witness 371 Index 375 PREFACE Forensic medicine is the science that deals with the application of medical facts and methods of investigation to legal problems and criminal matters. Hypoglycaemia, which is the term used to describe a low blood glucose concentration, is a common cause of people appearing in court. It may be raised by the defence because of the way it can change behaviour or by the prosecution because it has been used as weapon. Hypoglycaemia is not a disease but a consequence of it and can lead to radical and always temporary changes in behaviour that can turn a normally law-abiding citizen into a criminal. The only com- mon cause of hypoglycaemia encountered in practice is insulin, the best-known drug used for treating diabetes. Paradoxically, insulin can, through its ability to produce hypoglycaemia, also be used as a murder weapon. Hypoglycaemia has many causes apart from the overtreatment of diabetes with insulin, but, because overtreatment is so common, it has led to confusion between hypoglycaemia and diabetes – its exact opposite. Although the ways that hypoglycaemia affects peo- ple are the same throughout the world, the ways the law deals with it are different. This presents a problem in preparing a book deal- ing with both the medical and legal aspects of hypoglycaemia and this book concentrates solely on the medical aspects of the subject. Glucose is the only sugar that circulates in the blood of mankind in anything more than miniscule amounts. It is one of the two main fuels used by the tissues to maintain their vital functions. In most tissues – the nervous system being the most important exception – fats and their partially oxidised metabolites, known as ketones, can fulfill this function equally as well as glucose. It is therefore the viii preface nervous system that bears the brunt of any shortage of glucose sup- ply, and all the adverse effects of hypoglycaemia are because of it. In healthy people the concentration of glucose in the blood is tightly controlled by a complex system involving the liver, the ali- mentary tract and a number of hormones of which two, insulin and glucagon, both produced in the pancreas, are far and away the most important. The whole process of blood glucose control is referred to as glucose homeostasis. When this goes wrong, it leads to either an abnormally high concentration of glucose in the blood (hyper- glycaemia) or, more rarely, to an abnormally low concentration of glucose in the blood (hypoglycaemia). This book is concerned only with hypoglycaemia, its effect upon brain function and how this leads to conflicts with the law. Hypoglycaemia, in contrast to diabetes, is comparatively uncom- mon in the general population. Though known to exist from the time it first became possible to measure glucose in the blood in the late nineteenth century, almost nothing was known of its effects on the body until insulin was first used for the treatment of diabetes in 1922. Within a year, it became apparent that the effects of hypogly- caemia on a person’s well-being and behaviour were just as dramatic as that of diabetes, but totally different. Hypoglycaemia occurs most commonly in people undergoing treatment for diabetes, either with insulin or one of the sulphonyl- urea class of drugs in everyday clinical practice, but it can arise de novo as a manifestation of many types of disease. Signs and symptoms of hypoglycaemia are usually quite mild, and people who use insulin to treat their diabetes recognise them for what they are and can rapidly bring them to an end by eating or drinking something sugary. Sometimes, however, it produces changes in behaviour that bring the sufferer into contact with the law. Offences can vary in intensity and severity from the use of abusive language, petty theft and dangerous driving to mania- cal homicide. Most jurisdictions accept that a person affected by hypoglycaemia may be incapable of formulating intent to commit a crime, leading to them being exonerated or having their offence mitigated. preface ix There are other ways than misbehaviour in which hypoglycae- mia plays a key role in cases that come before the courts. Failure by professional health carers to recognise and treat it properly can lead to charges of medical negligence, and both insulin and sulpho- nylureas have been used as murder weapons, to enhance sporting performance and for other criminal practices. In the 95 years or so since the discovery of insulin, an exten- sive literature on hypoglycaemia and the law has been published, mostly in the biomedical and legal literature. There is, however, no authoritative text designed to be read by both lawyers and bio- medical personnel called upon to prosecute, defend or give expert advice in civil, criminal or coronial cases in which hypoglycaemia plays a key role. This book largely summarises my experience of hypoglycaemia spanning some 50-plus years and is an attempt to correct this defi- ciency. I have used cases in which I have been personally involved to illustrate some of the problems that arise in a forensic situation, as well as drawn extensively on the published literature, as these differ in many important respects from those experienced in the everyday practice of medicine. I have referred to the relevant scientific, medical and legal litera- ture for the benefit of those who need it for their own professional purposes without, I hope, interfering with the pleasure of those reading the book out of interest or curiosity. Some of the names of individuals and locations have been altered to protect the innocent.