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WELCOME TO THE WORLD OF FORENSIC MEDICINE Marie Cassidy Professor of Forensic Medicine and State pathologist FORENSIC MEDICINE THE BRANCH OF MEDICINE THAT APPLIES THE PRINCIPLES AND KNOWLEDGE OF THE MEDICAL SCIENCES TO PROBLEMS IN THE FIELD OF LAW FORENSIC MEDICINE/PATHOLOGY ‘Scientific’ investigation of the cause of injury and death in unexplained circumstances particularly when criminal activity is suspected FORENSIC SPECIALISTS • • • • • • • • Forensic pathologist ‘forensic’ pathologist/neuropathologist G.P. Police surgeon Accident and emergency doctor Forensic physician Paediatricians Forensic Psychiatrist FORENSIC SPECIALISTS • • • • • • • • • Forensic pathologist - suspicious deaths ‘forensic’ pathologist- nonsuspicious deaths Neuropathologist – head injuries, brain damage G.P.- injured or deceased patients Police surgeon-prisoner, drink driver, victim Accident and emergency doctor - injured Forensic physician - a/a, sexual crimes Paediatricians- any abnormality in children Forensic Psychiatrist- prisoners FORENSIC EXAMINATIONS • • • • • • • • WOUNDS AND INJURIES SEXUAL ASSAULTS CHILDREN SCENE OF DEATH DETERMINATION OF DEATH CAUSE OF DEATH POSTMORTEM EXAMINATIONS COURT TESTIMONY AND REPORTS INVESTIGATION OF DEATHS • To determine the cause and the manner of death • To identify the deceased if unknown • To determine the time of death and injury • To collect evidence from the body that can be used to prove or disprove an individual’s guilt or innocence and to confirm or deny the account of how the death occurred INVESTIGATION OF DEATHS • • • • To document injuries or lack of them To deduce how the injuries occurred To document any natural disease present To determine or exclude other contributory or causative factors to the death • To provide expert testimony if the case goes to trial ‘Forensic pathology, DiMaio’ DEALING WITH DEATH The doctor and death The dead patient • History • Examination • Diagnosis of death Definition of DEATH CESSATION OF LIFE IN A PREVIOUSLY VIABLE ORGANISM DEATH A DOCTOR MUST DECLARE DEATH ?duty of care to determine death DEATH • • • • Somatic death Molecular death Brain death Brain stem death • NO law defines death SOMATIC DEATH • Failure of the body as an integrated system • loss of circulation, respiration and innervation • for such a time impossible for life to return • irreversible unconsciousness Somatic death • Heart stops no pulse, no heart sounds, flat ECG, segmentation of blood in retinal vessels • Lungs stop no breathing, no chest movement • Brain activity stops • muscles floppy • metabolism stops, body cools down Somatic death • Auscultate for 4 to 5 minutes • D.D. shock, hypothermia, electrocution, depressant drugs MOLECULAR DEATH • Depends on susceptibility to oxygen deprivation • varies - important in organ harvesting • brain most susceptible, 3 to 7 minutes • wbcs may remain motile for up to 12hours • muscles respond to stimuli for few hours • skin viable for several days • importance - transplants BRAIN DEATH • CORTEX • BRAIN STEM • WHOLE BRAIN BRAIN DEATH CORTICAL brain death • deep coma • brain stem functioning BRAIN DEATH PERSISTANT VEGETATIVE STATE • functioning brain stem but non functioning higher centres • respiratory centres functioning do not require permanent assisted ventilation • require parenteral feeding • if heart protected from hypoxic damage and nutrition sustained, may survive for years BRAIN DEATH BRAINSTEM INJURY • COMA due to damage to the ascending reticular activating system • require assisted ventilation due to failure of the respiratory motor system • beating heart BRAIN DEATH Severe irreversible cortical damage + Brain stem damage WHOLE BRAIN DEATH Beating heart donor Brain stem death tests 1. Absent pupillary response to light 2. Absent corneal reflex 3. No motor response within the cranial nerve distribution and the limbs 4. Absent gag reflex 5. Doll’s eye phenomenon 6. No vestibulo-ocular reflexes 7. Persistent apnoea when ventilator disconnected Cause of Death Cause of death “The pathologist is bound to rely in part on what he/she is told of the events leading up to death for functional lapses like fall in blood pressure, cardiac arrythmia, spasm of the glottis or vagal inhibition which leave no trace at autopsy.” Simpson THANATOLOGY SUDDEN NATURAL DEATH Sudden Death • • • • Deaths at home Deaths in hospital Death outside Death in unusual circumstances: place, position, appearance of body Sudden Death • • • • G.P. or Hospital doctor Medical history Treatment for recent illness Other information Sudden Death • • • • Natural death Accident Suicide Homicide Sudden Death Age • Children • Teenager/young adult • Adult • Elderly Sudden Death Children • Stillbirths • Congenital abnormalities • Sudden infant death syndrome • Tumours Sudden Death Young adults • Suicide • Accidents - RTAs • Homicides • Natural Sudden Death Adults • Natural • Accidents - RTAs • Homicides • Suicides Sudden Natural Death In the developing world sudden cardiac death remains the major cause of death Adults and elderly • Cardiovascular disease • Cancer SUDDEN NATURAL DEATHcardiac causes • CORONARY ARTERY DISEASE, ischaemic heart disease, atheroma, thrombosis, dissection, ‘bridging’, acute MI, cardiac tamponade, stress associated • HYPERTENSIVE HEART DISEASE, acute LVF, arrythmia • CARDIOMYOPATHY, dilated/congestive, hypertrophic (commonest genetic cause of sudden death), genetic • VALVULAR HEART DISEASE, ‘floppy’ mitral valve, aortic valve stenosis SUDDEN NATURAL DEATH • MYOCARDITIS • AORTIC DISSECTION hypertension/heredity/inflammation, Marfan’s • Arrhythmogenic Right Ventricular Dysplasia –genetic – MRI – 20% sudden cardiac deaths – cardioverter/defibrillator • RUPTURE OF AORTIC ANEURYSM SUDDEN NATURAL DEATH PHYSIOLOGICAL – • Wolff-Parkinson-White, • long QT syndrome, ion channelopathy– congenital (inherited as a dominant gene) or acquired (antipsychotic/antiarrhythmic/allergy drugs, electrolytes, toxins, hypothermia, anorexia nervosa, dieting with liquid protein diets) SUDDEN NATURAL DEATHCNS causes • EPILEPSY - SUDEp • SUBARACHNOID HAEMORRHAGE berry aneurysms • INTRACEREBRAL HAEMORRHAGEhypertension • INTRACRANIAL PATHOLOGY ASSOCIATED WITH ACUTE HYDROCEPHALUS OR EPILEPSY tumours,meningitis SUDDEN NATURAL DEATH PSYCHIATRIC PATIENTS, Schizophrenics +/- phenothiazine, Neuroleptic malignant syndrome SUDDEN NATURAL DEATH • • • • • EPIGLOTTITIS PULMONARY THROMBOEMBOLISM ASTHMA HAEMOPTYSIS, T.B., tumour SPONTANEOUS PNEUMOTHORAX OF THE NEWBORN SUDDEN NATURAL DEATH • HAEMATEMESIS, rupture of oesophageal varices, duodenal ulcer • CHRONIC ALCOHOLICS, acute fatty degeneration of the liver • ADRENAL HAEMORRHAGE, septicaemia SUDDEN NATURAL DEATH – other causes • • • • • • AIR EMBOLISM FAT EMBOLISM AMNIOTIC FLUID EMBOLISM Ruptured ectopic pregnancy Toxic shock syndrome Sudden death in Diabetes – IHD, CM, hypo or hyperglycaemia • Sudden death in alcohol • Commotio cordis Sudden death Sudden adult death syndrome ‘SADS’ Sudden Arrhythmic Disease Syndrome Sudden Death The negative autopsy SADS • Sudden unexpected death in an adult • no signs or symptoms prior to death • postmortem shows no anatomical cause of death • specialised pathology examinations negative e.g. neuropathology • toxicology negative • bacteriology etc. negative • presumed cardiac dysrrhythmia SADS Now agreed to be due to acute onset of a chaotic rhythm in the heart SADS Risk factors include • A family history of unexplained sudden death in a relative under 40years • Unexplained fainting in young people • Approx 1000 cases/year in UK SADS Differential Diagnosis • ARVD – abnormal ECG, anatomical changes may not be obvious at postmortem; 30-50% have a family history • Disorders of the Ion Channel – Long QT syndromes, Brugada Syndrome (south east Asia), Catecholaminergic Polymorphic Ventricular Tachycardia (AD; Finland and Italy) SADS Treatment • Defibrillation • Implantable defibrillator Sudden adult death Sudden death during sporting activities Sudden death in sport • • • • • • • • Males > females USA - 1 : 133,000 males USA - 1 : 800,000 females usually underlying, undiagnosed congenital heart disease cardiomyopathy most common anomalous coronary circulation viral myocarditis > 40 years - coronary artery disease Child Deaths 50% due to Natural causes Genetic or congenital disorder Cot death - SIDS Infections Neoplasms CNS disorders U.K - risk of abnormal baby = 1:40 Child Deaths 50% of Neonatal deaths occur in first 2 days Prematurity Hypoxia Congenital Abnormality Birth Injury Still Birth S.I.D.S (Cot Death) The sudden death of any infant or young child, which, from the case history, is unexpected, and in which a thorough postmortem examination fails to demonstrate an adequate cause for the death. It is a diagnosis of exclusion S.I.D.S Features Age - 2 weeks to 2 years few after 9 months male>female Time - during sleep 80% found dead by 6am weekends>weekdays COLDER months S.I.D.S Features Prematurity low birth weight twins urban>country Lower social classes Poor social classes Young mothers/single parent/smoker Theories Sleeping position Over heating pvc mattresses sleep apnoea viruses-cause or incidental small size of larynx trace metal deficiency allergy to cow’s milk abnormal nervous conducting system to heart excess Na in feeds overhead electric cables nuclear power stations Theories Autopsy Findings 1. Nothing 2. Non- specific findings froth at mouth petechial haemorrhages congestion of lungs 3. Manifest illness- NOT SIDS