Head injury Flashcards
Primary insult to the head
-Focal/diffuse brain trauma
Secondary insult
- Hypotension
- Hypoxia
- Infection
- Haematoma
Initial assessment of a head injury is via?
Glasgow coma scale
How does the GCS rate head injury
1-15
15-13: Mild injury
12-9: moderate injury
3-8: severe injury
Eye opening in GCS
Spontaneous: 4
To loud voice: 3
To pain:2
Not at all: 1
Verbal response in GCS
orientated: 5
confused: 4
Inappropriate:3
Incomprehensible: 2
None: 1
Motor response in GCS
Obeys:6 Localises :5 Flexion:4 Abnormal flexion (twisted arm) :3 Extension posturing :2 None :1
Consequences of head injury
- Physical disability
- Post-traumatic epilepsy
- Intracranial infection
- Psychiatric illness
- Chronic subdural haematoma
- Punch-drunk dementia- dementia associated with head injury
- Fatal outcome
How do head injuries occur?
- Debilitating disease
- Accidental
- Homicidal
Different types of head injuries
- Scalp
- Skull fractures
- Haemmorage
- Diffuse traumatic axonal injury
- Intrinsic brain injury
Scalp injuries
Abrasions/ lacerations
Often associated with damage to the skull
Blunt laceration can lead to damage which might not be superficial on the scalp
Hair might cover size of tear
Bleeding and bruising may be present in the deeper layers of the scalp closer to the skull
Different types of skull fracture
Linear Depressed Comminuted Ring fracture Coutre-coup
What is a linear fracture
- Usually at parieto-temporal suture
- Due to fall onto top or side of head
- Continues into skull base
What is a depressed fracture
Fracture which leads to sections of the brain being pushed in against blood vessels
what is a comminuted fracture
Fragmented skull
What is a ring fracture
Damage to foramen magnum
Related to brainstem and spinal cord being pushed together- usually a result of a fall from a height landing on feet
What is a contre-coup
Fracture from hitting the head on the back
Leads to damage in the anterior cranial fossa
which are the parts of the skull which can be affected by a fracture?
- Skull base: anterior/middle and posterior cranial fossa
- Skull vault: skull and sutures
Intracranial hemmorage types
- Extradural
- Subdural
- Subarachnoid
What is an intracranial hemmorage
A build up of blood in the brain which leads to an increase in intracranial pressure.
The increase in pressure can ultimately lead to compression of the Braim.
If the compression leads to the cerebral tonsils being pushed against the spinal cord this will lead to death.
Characteristics of a extradural hemmorage
Blood between the dura and the skull
Build up of blood here will eventually lead to the dura being pulled off the skull
Usually associated with large pressure arteries rather than veins in reaction to a skull fracture
Commonly associated with a Middle meningeal artery rupture of the pterion
Build up of intracranial pressure- can take hours for symptoms to present:
- Patient may have a lucid period where they appear to be completely fine
- This can have catastrophic consequences
Characteristics of a subdural hemmorage
Usually related to the fracture of veins which drain the venous sinuses underneath the dura.
It is usually caused by a rotational sheer force which causes the vessels to rupture.
Who is likely to suffer from a subdural hemmorage?
- People with atrophic brains: more room between the brain and the skull
- In the elderly: can present as chronic. Often mistaken with dementia as it causes loss of lucidity
Characteristics of a subarachnoid hemorrage
Most commonly associated with disease: e.g. rupturing of cerebral arteries.
Usually sudden death due to the irritant effects of blood
Traumatic basal SAH
Associated with a severe blunt to the neck which cause rotational movement of head- this causes the circle of willis to become ruptured and SAH on the base of the brain.
Examples of intrinsic brain injury
- Cerebral oedema
- Cerebral contusion: mechanical damage to the brain
Different types of cerebral contusion?
Coup contusion:
- when head stuck with blunt force
- Contusion is found directly under the strut area
Contre-coup:
- when moving head strikes against object
- Contusions are found diametrically opposite the site of head impact
How is diffuse axonal injury diagnosed?
- Diagnosis can only be made based on microscopy of the brain
- Small vessels involved/damaged may increase suspicions
- Usually associated with vehicle incident/ falls from a height
- Rotational forces to the head lead to shearing of axons
which areas are most prone to diffuse traumatic axonal injury?
- corpus callosum
- Cereberllar peduncles
- Posterior internal capsule
- para-sagittal white matter
