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 DEATH- cardiac 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 DEATH-CNS causes

• EPILEPSY - SUDEp• SUBARACHNOID HAEMORRHAGE -

berry aneurysms• INTRACEREBRAL HAEMORRHAGE-

hypertension• 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 causesGenetic 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 daysPrematurity

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

FeaturesAge - 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

FeaturesPrematurity

low birth weight

twins

urban>country

Lower social classes

Poor social classes

Young mothers/single parent/smoker

Theories

Sleeping position

Over heatingpvc 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