Chapter 3: Thanatology - Detailed WBUHS Exam-Oriented Answers

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LONG & SHORT ANSWER QUESTIONS (5 & 4 Marks)

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Q1. Define Sudden Death. Enumerate causes of sudden death. Enumerate immediate, early and late changes after death. Write a note on postmortem biochemistry helping in estimation of time since death. (1+3+3+3=10) - Barasat GMC

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1. Cessation of respiration
2. Cessation of circulation (cardiac arrest)
3. Loss of consciousness
4. Loss of reflexes (corneal, pupillary)
5. Pupils fixed and dilated (mydriasis)
6. Muscles become flaccid (primary relaxation)
7. Loss of skin colour (pallor)
8. Relaxation of sphincters (bladder, bowel)
9. "Tache noire" - brownish-black areas on exposed sclera if eyes remain open (within 3 hours)

1. Cooling of the body (Algor Mortis):

• Body temperature falls after death due to cessation of metabolic heat production
• Rate of cooling: approximately 1.5°F (0.8°C) per hour under average conditions (Henssge nomogram)
• Algor mortis curve is sigmoid shaped (important exam point from P.C.SEN ARAMBAGH)
• Factors accelerating cooling: thin body, high ambient temperature differential, wet clothes, wind
• Factors retarding cooling: obese body, clothed body, warm environment

1. Postmortem Lividity (Livor Mortis/Hypostasis):

• Discolouration due to accumulation of fluid blood in toneless capillaries of dependent parts
• Begins within 1-3 hours (mottled patches)
• Coalesces at 3-6 hours
• Fixed (non-blanching) at 6-8 hours
• Fixation is due to packing and stagnation of blood in distended capillaries (NOT coagulation)

1. Rigor Mortis:

• Stiffening of muscles due to fusion of actin-myosin filaments
• Appears 1-2 hours after death; fully developed at 6-12 hours; passes off at 24-48 hours
• Follows Nysten's law: descends from jaw (face) to neck to trunk to limbs

1. Changes in Eye:

• Cornea becomes cloudy, intraocular tension falls
• Retinal vessels show "cattle-trucking" appearance
• Potassium content of vitreous humour rises steadily

1. Putrefaction:

• Decomposition by autolysis and bacterial action
• Green discolouration appears first over right iliac fossa (caecum - most bacteria)
• Bloating, gas formation, marbling (greenish-black lines over skin following blood vessels)
• Blister formation, liquefaction
• Chief organism: Clostridium welchii (produces lecithinase causing haemolysis)

1. Adipocere Formation (Saponification):

• Conversion of body fat into adipocere (a pale-white waxy substance)
• Occurs in bodies exposed to warm, moist conditions (buried in wet soil, drowned)
• Requires 3-12 months minimum
• Medicolegal importance: preserves body contours and may retain evidence of injury

1. Mummification:

• Dehydration of tissues in hot, dry, well-ventilated conditions
• Body becomes hard, brown and leathery
• Preserves body indefinitely
• Medicolegal importance: body may be recognisable; evidence of injury retained

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• Vitreous humour is uniquely stable and highly useful because it is protected from putrefaction by the intact globe (important: IPGME&R and SSKM)
• Vitreous K+ rise is the most reliable biochemical marker

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Q2. Enumerate the early signs of death. What is the mechanism of development of Rigor Mortis? How will you estimate time since death from different findings during autopsy? (2+3+5=10) - JMN Medical College, Chakdaha

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1. Absence of pulse and heartbeat (auscultation x 3-5 minutes)
2. Cessation of respiration
3. Fixed dilated pupils - loss of light reflex
4. Loss of corneal reflex
5. Loss of skin elasticity, pallor
6. Postmortem lividity (begins within 1-3 hours)
7. Cooling of body (algor mortis)
8. Flaccidity of muscles (primary relaxation)
9. Tache noire on sclera (within 3 hours if eyes open)
10. ECG shows flat line (asystole)

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1. Circulation stops - no oxygen delivery
2. Cells switch to anaerobic glycolysis - lactic acid accumulates
3. Muscle pH falls from alkaline to distinctly acid (lactic acid)
4. When glycogen is exhausted, ATP cannot be resynthesised
5. Without ATP, the actin-myosin cross-bridges CANNOT be broken
6. Actin and myosin fuse into a dehydrated stiff gel - this is RIGOR MORTIS
7. This persists until autolysis of myosin and actin filaments occurs during putrefaction
8. Then secondary relaxation sets in (muscles become flaccid again, alkaline reaction returns)

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Q3. Define Rigor Mortis. Write the Mechanism of formation of rigor mortis. How will you differentiate between rigor mortis and cadaveric spasm? (1+5+4=10) - ICARE Institute of Medical Sciences

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• Rigor = rigidity; Mortis = of death

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1. Proves the last voluntary act of the deceased before death
2. If weapon is found tightly clutched in hand - suggests suicide (not planted post-mortem)
3. Weeds or grass clutched in hands of drowned persons - proves active drowning struggle
4. Considered a sign of antemortem activity (ESIC JOKA)
5. Has greater medicolegal importance than rigor mortis (Raiganj)

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Q4. Declare a person dead / Brain stem death / Modes and Manner of Death (R.G. Kar Medical College - 4+4+1+4+2=15)

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1. No pulse - palpate carotid, brachial arteries for at least 1 minute
2. No heartbeat - auscultation x 3-5 minutes over all 4 areas
3. No respiration - observe for 2-3 minutes; mirror test (held before mouth/nose)
4. Fixed dilated pupils - no light reflex
5. Absent corneal reflex
6. ECG - flat isoelectric line
7. Look for early signs of death - lividity, cooling
8. Exclude suspended animation (drowning, electrocution, barbiturate overdose, epilepsy, hypothermia, yoga)

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• "Permanent and irreversible stoppage of the tripod of life" (circulation, respiration, nervous activity)
• Under Sec 46 IPC: death = death of a human being
• Under Births and Deaths Registration Act 2(b): "permanent disappearance of all evidence of life at any time after live birth"

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1. Coma (asphyxia) - failure starting from nervous system
2. Syncope - failure starting from circulation
3. Asphyxia - failure starting from respiration

1. Natural
2. Accidental
3. Homicidal
4. Suicidal
5. Undetermined (NASH + U classification)

• Immediate (direct) cause
• Antecedent cause
• Underlying/fundamental cause

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1. Examine the body thoroughly before declaring dead
2. Exclude suspended animation
3. Issue Death Certificate (Form 4 under Registration of Births and Deaths Act)
4. Issue MCCD (Medical Certificate of Cause of Death) if natural death confirmed
5. If medicolegal case (trauma, suspicious death) - inform police, do NOT issue MCCD; body sent for autopsy
6. Prepare and sign inquest report
7. Make clear note of time of declaration of death and all findings

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Q5. Define Brain-stem Death and its Medico-legal Importance. Describe mechanism and typical progression of Rigor Mortis. What is exhumation? What is the procedure of exhumation? - KPC Medical College, Jadavpur

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1. Medullary neurons are most resistant to anoxia - if dead, all higher centres are also dead
2. Brain stem contains respiratory and circulatory centres
3. All sensory and motor fibres pass through the brain stem (gateway to cortex)
4. Brain is the seat of consciousness and individuality

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1. Unreceptivity and unresponsivity to external stimuli
2. No spontaneous movements for at least 1 hour
3. Apnoea - absence of spontaneous breathing (ventilator off for 3 minutes)
4. Absence of reflexes (fixed dilated pupils, absent corneal reflex, absent gag reflex, absent deep tendon reflexes)
5. Isoelectric (flat) EEG (confirmatory value)

• Tests repeated at 24 hours with no change

1. No spontaneous movements
2. Apnoea (ventilator off for 4 minutes - no breathing attempt)
3. Absent brainstem reflexes: pupillary, corneal, ciliospinal, oculocephalic, vestibulo-ocular
4. Flat isoelectric EEG
5. EEG not mandatory
6. Spinal reflexes not important
7. All findings unchanged for at least 12 hours

• Brain death declared by a board of 4 doctors:

1. Medical officer in charge of the hospital
2. An authorized specialist (neurologist/neurosurgeon)
3. The treating physician
4. The doctor of the donor (if transplant)

• Must be confirmed twice with a gap of 6 hours

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1. Allows withdrawal of ventilatory support (no further obligation to continue)
2. Allows organ donation and transplantation (kidneys, liver, heart, corneas)
3. Relevant for settlement of insurance claims and inheritance
4. Prevents unnecessary prolongation of futile treatment
5. Legal protection for the medical team

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1. Jaw muscles and face (1-2 hours)
2. Neck (2-4 hours)
3. Upper limbs (4-6 hours)
4. Trunk (6-8 hours)
5. Lower limbs (8-12 hours)

• Fully established at approximately 12 hours
• Begins to pass off at 24-36 hours
• Completely resolved at 36-48 hours

• Age: Absent in fetuses, feeble in elderly, well-marked in muscular adults
• Body build: Muscular persons show more marked rigor
• Cause of death: Rapid/early rigor in exhaustion, heat stroke, convulsions, strychnine poisoning, tetanus; Delayed/absent rigor in septicaemia, drowning, wasting diseases
• Temperature: Hot environment accelerates onset and hastens disappearance; cold delays
• Septicaemia: Rigor mortis passes off early in septicaemic deaths (Bankura Sammilani - exam point)

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1. When crime is suspected after burial
2. To establish identity
3. To determine cause of death when it was not properly established before burial
4. Suspected poisoning (especially arsenic - well-preserved in soil)
5. For civil litigation (insurance, inheritance)

1. Written order from Magistrate
2. Police officer (not below Inspector) to be present
3. The forensic medicine expert (autopsy surgeon) attends
4. Exhumation should ideally be done in the morning (not night)
5. The exact site of the grave is identified by the grave-digger/witness
6. Soil samples from top, sides, and bottom of grave are collected (for toxicology comparison)
7. Body is exhumed carefully
8. Coffin/shroud examined for any evidence
9. Full identification details documented (clothing, ornaments, physical features)
10. Complete postmortem examination performed at the site or mortuary
11. All viscera preserved in separate airtight containers with preservative
12. Samples for toxicology: liver, stomach contents, kidney, hair, nails, bone
13. Body is reburied after examination
14. Detailed report submitted to the Magistrate

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Q6. Persistent Vegetative State / Permanent Vegetative State / Brain Death / Minnesota Criteria - Jhargram Medical College (1+1+4+2+2=10)

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1. Medical superintendent / authorised officer of the hospital
2. An authorised specialist (neurologist or neurosurgeon) nominated by the hospital
3. The treating physician of the patient
4. A doctor nominated by the nearest transplant authorisation committee

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Q7. Post-Mortem Changes: Define Rigor Mortis, Mechanism, Conditions resembling Rigor, Factors affecting - Malda Medical College (1+4+2+3=10)

1. Cadaveric Spasm (Instantaneous Rigor):

• Immediate stiffening without primary relaxation
• Due to extreme nervous energy at moment of death
• Affects muscles in active use; rare

1. Cold Stiffening (Freezing):

• Due to freezing of tissues at sub-zero temperatures
• On thawing, stiffness disappears rapidly and THEN true rigor develops (shorter and less intense)
• Bodies in cold chambers (4°C) undergo cold stiffening due to solidification of body fat

1. Heat Stiffening (Heat Coagulation):

• Occurs at >70°C (burning, high-voltage electrocution, vats of hot liquid)
• Heat coagulates muscle proteins - stiffening greater than rigor mortis
• Body assumes pugilistic attitude (semi-flexed limbs, clenched fists - like a boxer)
• Normal rigor mortis does NOT develop in these cases
• Persists until coagulated albumin liquefies during decomposition

1. Gas Stiffening (Putrefaction rigidity):

• Accumulation of putrefactive gases in tissues causes false rigidity
• Stiff limbs can be held up without support
• Occurs late; associated with putrefactive changes

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Q9. What are the Uses of MCCD? (10) - P.C.SEN, ARAMBAGH

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1. Statistical use: Collection of vital statistics on mortality trends, causes of death at national and international level (WHO mortality data)
2. Registration of death: Required for official registration at the office of Registrar of Births and Deaths
3. Legal purposes: Required for obtaining death certificate for settlement of insurance claims, inheritance, property, pension, remarriage
4. Public health use: Helps identify epidemics, disease burden, identification of risk factors; used in disease surveillance
5. Planning: Health planning authorities use MCCD data for resource allocation, health policy decisions
6. Research: Used in epidemiological research and mortality studies
7. Criminal investigation: Helps detect cases where criminal death may have been certified as natural
8. Cremation/burial: Required by crematoria and burial grounds as authority for disposal of body
9. International comparison: WHO compiles global cause-of-death statistics from national MCCDs
10. Insurance: Required to claim life insurance policies

• Part I: Direct cause of death (a - immediate; b - antecedent; c - underlying)
• Part II: Other significant conditions contributing to death (not in causal sequence)

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Q11. Football player collapsed on field: Negative Autopsy / Obscure Autopsy / Molecular Autopsy (3+3+4=10) - BMC

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• Commotio cordis (cardiac concussion from chest trauma) or
• Hypertrophic Cardiomyopathy (most common structural cause of SCD in young athletes)
• The blow triggers ventricular fibrillation
• Sudden loss of cardiac output - irreversible brain damage in 4-6 minutes

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• An autopsy where no gross or histological cause of death is identified
• Also called "negative autopsy" or "autopsy with no anatomical cause of death"
• Occurs in: Sudden Infant Death Syndrome (SIDS), cardiac arrhythmias (no structural changes), drug overdose (if toxicology not done), hypoglycaemia, anaphylaxis

• An autopsy where despite thorough investigation, the cause of death remains obscure or uncertain
• The findings are insufficient to explain death with confidence

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• Application of molecular genetic techniques to post-mortem tissue to determine the cause of unexplained death
• Especially important in young individuals with no structural cardiac cause
• Techniques used: Next generation sequencing (NGS), PCR, gene expression profiling

1. Long QT syndrome (LQTS) - mutations in KCNQ1, KCNH2, SCN5A genes
2. Brugada syndrome - SCN5A gene mutation
3. Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) - RYR2 gene
4. Hypertrophic Cardiomyopathy - MYH7, MYBPC3 genes
5. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) - desmosomal genes

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Q12. Objectives of Autopsy + Time since death by naked eye changes (3+7=10) - MCK

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1. Determine the cause of death (immediate, antecedent, underlying)
2. Determine the manner of death (natural, accidental, homicide, suicide)
3. Determine the time since death
4. Establish identity of the deceased
5. Collect evidence for legal proceedings (preserve viscera, collect trace evidence)
6. Determine whether ante-mortem injuries are consistent with alleged mechanism
7. Determine if adequate medical/surgical treatment was provided (professional negligence cases)

1. Quality control of clinical diagnoses
2. Determine missed diagnoses
3. Assess effectiveness of treatment
4. Teaching and research

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SHORT NOTES & EXPLANATIONS (4 & 5 Marks)

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Rigor Mortis Passes Off Early in Septicaemic Deaths (Bankura Sammilani)

• In septicaemia, bacterial toxins and high fever deplete muscle glycogen rapidly
• This causes early onset of rigor but also accelerates autolysis
• The resulting early destruction of muscle proteins means rigor is brief and feeble
• Also, acidosis and toxaemia denature muscle proteins, preventing stable actomyosin gel formation

Cadaveric Spasm - Medicolegal Importances (Jagannath Gupta Institute)

Criterion of Declaring Brain Stem Death in India (Calcutta National Medical College)

Vitreous Humour Chemistry - Uniquely Stable and Highly Useful for PMI (IPGME&R & SSKM)

1. Protected within the rigid bony orbit and intact globe
2. Avascular - not affected by putrefaction of blood
3. Physical barrier - resistant to contamination by gut bacteria
4. Changes are predictable and measurable

• Formula: Postmortem interval (hours) = (K+ - 7.14) / 0.14
• Rises at approximately 1 mEq/L per hour
• Reliable up to 120 hours

Algor Mortis Curve is Sigmoid Shaped (P.C.SEN, ARAMBAGH)

• Initially the rate of cooling is SLOW (first 1-2 hours) - body heat production continues briefly and thick clothing/fat insulates
• Then cooling is RAPID (maximum rate phase)
• Finally the rate slows again as temperature approaches ambient
• This gives a characteristic sigmoid (S-shaped) curve when temperature is plotted against time

Exhumation (Rampurhat Government Medical College)

Negative Autopsy (Diamond Harbour Government Medical College)

Suspended Animation - Must be Ruled Out (IQ CITY)

• Prolonged auscultation (>5 minutes)
• ECG
• Magnus test (tight ligature - watch for discolouration)
• Winslow's test (bowl of water on chest - watch for ripples)
• Diaphanous test (strong light behind ear - if alive, ear will glow red)
• Arteriotomy (cut radial artery - if alive, blood spurts)

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