Head Injuries Study Notes

Head Injuries

Overview

  • Speaker: Ajith Tennakoon, Chief Consultant JMO.

Commonality of Head Injuries

  • Head injuries are prevalent in:

    • Violent deaths

    • Road Traffic Accidents (RTAs)

    • Falls

  • Indicates intensity in cases of violent deaths.

  • The head is the heaviest and most movable part of the body, making it more vulnerable during falls.

  • Common sites for head injuries in suicides; elected areas.

Causation of Head Injuries

  • Direct Trauma

  • Indirect Trauma:

    • Falls on heels or buttocks can cause ring fractures.

    • A blow to the chin can cause basal fractures.

  • Acceleration and Deceleration Injuries:

    • Commonly seen in RTAs (Road Traffic Accidents).

Forensic Anatomy of the Head

  • Components include:

    • Hair

    • Scalp

    • Skull

    • Membranes: Dura, Pia, Arachnoid

    • Brain

Anatomy Notes

  • Emissary Vein & Cortical Vein

  • Dura Mater: Tough outermost membrane.

  • Subarachnoid space: Contains cerebrospinal fluid (CSF).

Effects of Hair on Head Injuries

  • Protection: Hair can protect the scalp from injury.

  • Concealment of Injuries: Injuries may be hidden under hair.

  • Abrasions: Rarely seen with scalp injuries.

  • Soot Deposition & Tattooing: Not observed in the context of scalp injuries.

  • It is often advisable to shave the hair to better visualize injuries.

Effects of Scalp on Head Injuries

  • Composition: Thick layer of dense fibrous tissue; very vascular, leading to profuse bleeding.

  • Swelling: Not considerable; evaluation through palpation is recommended (especially in firearm injuries).

  • Wounds: Differentiation between lacerations and cuts can be challenging; careful assessment necessary.

  • Scalp lacerations often heal rapidly but can lead to intra cranial infections.

Effects of Skull on Head Injuries

  • Structure: Composed of an outer and inner table with diploe in between; numerous bones joined at sutures.

  • Shape: Rounded, hollow with limited capacity; coordinates with ear, nose, and eyes.

  • Thickness Variations: Skull thickness varies in different areas.

Descriptions of Head Injuries

  • Important characteristics:

    • Nature, Size, Shape, Disposition, and Site of injuries.

    • Hair: Signs such as cuts indicate weapon type and nature of injury; singeing may indicate range of fire or explosion specifics.

    • Scalp: Types of injuries include abrasions, contusions, lacerations, burns.

    • Extracranial: Includes subscalper space hemorrhage, pericranium hemorrhage, and skull fractures.

Skull Fractures

  • Types of fractures include:

    • Linear/Fissured: Runs from impact site; characterized by both forward and downward components; influenced by Puppe’s Rule (second fracture terminates at first).

    • Ring Fracture: Typically results from indirect trauma.

    • Depressed Fracture: Caused by localized striking force; can help identify weapon and direction.

    • Other types: Hinge fractures, Pond fractures (in children), and Spider web fractures.

    • Injury characteristics depend on:

    • Weapon used

    • Force applied

    • Site of skull thickness variation

    • Support status of head during impact.

Complications of Skull Fractures

  • Potential complications include:

    • Brain injuries

    • Intracranial infections

    • Damage to cranial nerves

    • Post-traumatic epilepsy.

Intracranial Hemorrhage (ICH)

  • Epidural Hemorrhage (EDH):

    • Occurs between skull and dura mater primarily due to middle meningeal artery rupture; often associated with skull fractures.

    • Usually unilateral; may cause lucid intervals.

  • Subdural Hemorrhage (SDH):

    • Commonest form of ICH; occurs between dura and pia arachnoid; seen more frequently in extreme age groups.

    • Types include acute, subacute, and chronic SDH.

  • Subarachnoid Hemorrhage (SAH):

    • Rarely occurs on its own without brain injury; common association with aneurysms.

Cerebral Injuries

  • Injury mechanisms include:

    • Direct intrusion by foreign object

    • Deformation of the brain in closed head injuries:

    • Rotational movement and velocity changes are primary causes of damage.

  • Categories of brain injuries:

    • Coup Injuries: Directly underneath the point of trauma.

    • Contre-Coup Injuries: Opposite to the point of impact, often more severe with rotational impacts.

Sequalae of Head Injuries

  • Possible outcomes include:

    • Localized injuries with little systemic effect.

    • Minimal effects such as headaches and dizziness.

    • Prolonged unconscious states leading to recovery with or without disabilities, or death due to complications.

Cerebral Edema

  • Common following significant intra cerebral injury:

    • Leads to increased brain weight and compression of cranial structures.

    • Pressures may distort and obstruct ventricular flow, leading to secondary effects like herniation.

Basilar Vertebral Artery Injury

  • Important diagnostic considerations in diffuse SAH combined with neck trauma or rotation, often leading to sudden death.

Spinal Injuries

  • Related to mechanisms of:

    • Compression, hyperflexion, or hyperextension.

  • Types of spinal injuries may result from falls or disruptions in normal vertebral functions.

Head Injury and Categories of Hurt

  • Classification includes:

    • Non-grievous and Grievous (e.g., fracture skull, head injury with concussion, etc.).

    • Considerations of fatal versus non-fatal injuries are crucial from both medical and legal perspectives.

Frequent Legal Questions Related to Head Injuries

  • Queries regarding the potential for injury from falls, role of alcohol in head injuries, and recovery timelines post-injury are common in forensic contexts.

Acknowledgments

  • Thanks for attending the briefing on head injuries and their implications.