head injuries in forensic medicine

Fixed Learning Session - 3Intracranial injuries…Firearm & Blast injuries…Postmortem changes…

Objectives…You should utilize this FLS to achieve the following; Intracranial injuries

Identify the different features and causation of injuries.

• Fire armIdentify the injuries caused by different types of fire arm. Identification of entry and exit woundIdentify circumstances of firearm injury

• Postmortem changesIdentify the different types of postmortem changes at different time intervals.

Intracranial Injuries…The brain, its membranes and blood vessels are said to be the most fragile of all the organs of the body. That is why they are encased in a rigid bony box called the skull. Intracranial injuries include injury to the above soft tissues.

Objectives…You should utilize this FLS to achieve the

following; Intracranial injuries

Identify the different features and causation of injuries.

Case Scenario…A 25 yr old pedestrian was knocked down by a car and thrown onto the road. She was admitted to the ward in unconscious state.

1. List the possible types of intracranial haemorrhages that may be observed in a patient with head injury.

1. List the possible types of intracranial haemorrhages that may be observed in a patient with head injury.

1. Extradural haemorrhage (EDH)

2. Subdural haemorrhage (SDH)

3. Subarrachnoid haemorrhage (SAH)

4. Intracerebral haemorrhage (ICH)

2. Identify the lesion seen in this photograph.

2. Identify the lesion seen in this photograph.

Diffuse subarachnoid haemorrhage (SAH) over the cerebral hemispheres

This subarachnoid haemorrhage has resulted from rupturing of bridging vessels during rotation of the brain.

3. What are the other possible causes for SAH?

4. What are the other possible causes for SAH?

Extension of traumatic intracerebral haemorrhage Rupture of Berry aneurysmRupture of the AV malformationRupture/laceration of vertebral artery

Case Scenario…A patient who had a severe headache was admitted to the medical ward in an unconscious state. He was a hypertensive patient. Following abnormalities were detected during the autopsy.

1. Identify the abnormality pointed by the arrow.

1. Identify the abnormality pointed by the arrow.

Ruptured berry aneurysm

2. What is the type of intracranial haemorrhage you would expect to see in this person?

2. What is the type of intracranial haemorrhage you would expect to see in this person?

Basal subarchnoid haemorrhage

3. What is the most likely mechanism of death?

3. What is the most likely mechanism of death?

Basal subarachnoid haemorrhage causes vide spread vascular spasm which may have an effect on vital centers of the brain stem causing sudden collapse and death.

Case Scenario…A 40yr old man was assaulted with a wooden pole over the right side of the head. On examination there was a laceration over the right temporo-parietal region. The Xray of the skull showed an underlying fracture. Despite the medical intervention the patient succumbed to the injuries.

1. Identify the intracranial haemorrhage shown by this photograph.

1. Identify the intracranial haemorrhage shown by this photograph.

Extra dural haemorrhage

2. Name the responsible blood vessel causing above haemorrhage.

2. Name the responsible blood vessel causing above haemorrhage.

Middle meningeal artery

3. Describe the clinical picture of this person.

Lose of conciseness due to concussionFollowed by recovery and “lucid interval”Gradual decoration of the level of consciousness

3. Describe the clinical picture of this person.

Fact file…Intracranial Haemorrhages…

Extradural haemorrhage…(EDH)

This is the collection of blood between the skull and dura mater .

Since the dura is closely applied to the skull in the base it does not occur on the base except on the posterior fossa. Most extradural haemorrhages are associated with skull fractures.

Extradural haemorrhage…(EDH)

The classical clinical sign of extradural haemorrhage includes ‘lucid interval’.

A doctor may be accused of medical negligence if a patient is discharged from the hospital after the recovery of the concussion and died at home from complications of extradural haemorrhage.

Subdural haemorrhage…(SDH)This is collection of blood in the sudural space and it is much more common than extradural haemorrhage.

It can be classified in to acute and chronic and commoner in both extremes of life.

Subdural haemorrhage…(SDH)

In young it is infamously associated with fatal child abuse.

Acute SDH is a common result of any significant head injury. Majority of SDH are associated with skull fractures.

Subarachnoid haemorrhage…(SAH)This is collection of blood in the subarachnoid space.

The blood in the subarachnoid space tend to mix with CSF. Therefore unlike other haemorrhage less likely to clot.

Subarachnoid haemorrhage…(SAH)

SAH can also occur as a result of natural causes such as rupture of berry aneurysm and arterior-venous malformations.

Death from SAH may be instantaneous, particularly when there is haemorrhage around the brainstem.

Intracranial haemorrhage…(ICH)They can be either infiltrating brain tissue or forming actual haematoma in the brain tissue. Primary haemorrhages occur at the time of injury due to rupture of blood vessels.

Secondary haemorrhage occur due to the injured area undergoing swelling, softening, liquefaction, and cavity formation .The ruptured vessels at the margins bleeds into the cavity.

Firearm Injuries…A firearm is any instrument which discharges a missile by the expansive force of the gases produced by burning of an explosive substance.Forensic Ballistics is the science dealing with the investigation of firearms, ammunition and the problems arising from their use.

Objectives…You should utilize this FLS to achieve the

following;

•Fire armIdentify the injuries caused by different types of fire arm Identification of entry and exit woundIdentify circumstances of firearm injury

Fact file…There are 2 types of firearms…

2 types of firearms…Rifle Smooth bore

Case Scenario…A 50yr old male who was later revealed to be a leader of a local drug dealing gang was found dead at a junction of a road. There were multiple firearm injuries on the body of the victim. The victim was found to be shot from intermediate range.

1. How would you identify the type of firearm by examining the injuries ?

A

B

1. How would you identify the type of firearm by examining the injuries?

Rifle (A) Smooth bore (B)Edge of the wound

Circular hole with inverted margins

Scalloped edges (rat hole)

Satellite wounds

Absent Present

Wad mark Absent Present as a laceration/contusion below the main wound but not visible in this case

Abrasion collar

Present Absent

Grease ring Present Absent

Case Scenario…A 20yr old male was shot during a police raid. He was admitted to a surgical unit and the MO medico legal was summoned to do medico-legal examination of the patient. Eye witness reported that the man was shot by a rifle.

1. What are the features that would help the MO medico-legal to differentiate an entry wound from an exit wound?

A B

1. What are the features that would help the MO medico-legal to differentiate an entry wound from an exit wound?

Entry wound (A) Exit wound (B)

Shape Circular hole with inverted margins

Stellate and everted

Abrasion collar

Present Absent

Burning Blackening Tattooing

May be present depending on the range of fire but not present in this case

absent

Case Scenario…A 35yr old male was found dead inside a room with a circular laceration on the forehead.

1. Which of the following features will indicate this case as a firearm suicide?

1. Room is locked from inside.

1. Weapon is absent from the scene.

1. Presence of more than one fatal injury.

1. Elective site.

1. Entry wound is compatible with the handedness.

1. Injuries present in inaccessible area.

1. Which of the following features will indicate this case as a firearm suicide?

1. Room is locked from inside. (T)

1. Weapon is absent from the scene. (F)

1. Presence of more than one fatal injury. (F)

1. Elective site. (T)

1. Entry wound is compatible with the handedness. (T)

1. Injuries present in inaccessible area. (F)

Postmortem changes…The underlying biological processes that a human body or its remains undergo after death are called postmortem changes. There is a broad range of variables influencing postmortem changes by alteration of underlying process of tissue destruction. Understanding the resultant postmortem changes is of great importance to forensic pathologist.

Objectives…You should utilize this FLS to achieve the following; • Postmortem changes

Identify the different types of postmortem changes at different time intervals.

Early postmortem changes…Include;•Rigor mortis•Hypostasis•Dilation of pupils•Dropping of intraocular pressure•Loss of skin elasticity

Case Scenario…The body of a 27yr old adult male was found inside a motor car with a running engine. Following picture was taken during the autopsy.

1. What could be the likely cause of death?

1. What could be the likely cause of death?

CO poisoning

2. How would you confirm your diagnosis?

2. How would you confirm your diagnosis?

Venous blood sample for CO level from femoral vein

Fact file…The colour of hypostasis may indicate the cause of death…

Different colours of hypostasis…

Case Scenario…A body of a 20 year old male was recovered from a river. Following photograph was taken during the autopsy.

1. Identify the postmortem change seen in this photograph.


Cadaveric spasm

Cadaveric/Postmortem spasm is a form of muscular stiffening that occurs at the time of death persisting into the period of rigor mortis. It is usually associated with violent deaths with intense emotion.

2. What is the medico-legal significance of this?

2. What is the medico-legal significance of this?

It provides a clue that the individual was alive at the time of entering into the water.

Case Scenario…A 70 year old man who was living alone was found dead by the neighbors.

1. Identify the postmortem changes.

1. 1. Identify the postmortem changes

Skin blistersSkin slippageBloating of the bodyColour change of the skin

1. Depending on the postmortem changes roughly estimate the time since death.

1. Depending on the postmortem changes roughly estimate the time since death.

Time since death 48-72 hours

Late postmortem changes…Include;•Mummification•Adipocere formation•Skeletalization

Case Scenario…A body of a six (6) months old infant was exhumed for autopsy following allegations by relatives.


Adipocere formation

This is a rare phenomenon. The fat coverage of the body hydrolyse and hydrogenases. This forms a greyish white, greasy, friable substance with cheesy amonical smell. The time of onset is highly variable and is between 1- 6/12.

2. What is the environmental condition that is favourable for this .

2. What is the environmental condition that is favourable for this .

Warm and moist environment

2. List the important medico-legal significances of this change.


• Condition of disposal

• Preserve external features

• Identification of injuries

• Time since death : Minimum 3 -6 wks

Case Scenario…A body of an adult male was recovered from a desert like place. He went missing from home four (4) weeks ago.


Mummification

Needs hot dry and windy condition. Commonly seen in deserts. Tissues will dry and shrivelled preventing putrefaction. This results in stretching the skin. The condition may co –exists with adipocere.


• Condition of disposal

• Identification

• Identification of injuries

• Time since death - 2 - 4 wks

Identify the given postmortem artifact and click on the correct answer.

Rat bites

Ant bites

Fish bites

Predator attacks

Correct!

Click here for the explanation.

Wrong Answer.


Postmortem ant bites…

Ants can be present at all stages of decomposition as they are typically observed shortly after death or during the early postmortem period. The feeding action of ants can cause many irregular scalloped areas of superficial skin loss, and small punctuate and scratch-type lesions with well defined margins.Usually ant injuries are orange-pink to yellow in color and diffusely scattered over the skin surface.

These injuries can be easily misinterpreted as antemortem abrasions but the absence of inflammatory reactions helps to differentiate them from antemortem injuries.

Identify the given postmortem artifact and click on the correct answer.

Rat bites

Ant bites

Fish bites

Predator attacks

Correct!


Wrong Answer.


Predator attacks…

There are multiple parallel claw marks with no vital reactions probably inflicted by a water monitor.

Now can you? Identify the different features and causation of

injuries.

• Identify the injuries caused by different types of fire arm.

• Identify the different types of postmortem changes at different time intervals.

head injuries in forensic medicine

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