Head Injury Flashcards
What are the types of head injury?
Primary vs secondary
Traumatic vs non-traumatic
Mild vs moderate vs severe
What is primary head injury?
Head injury occurring immediately after head trauma
What is secondary head injury?
Head injury occurring a while after the head trauma
What are the types of primary head injury?
Focal
Diffuse
What are the types of primary focal head injury?
Haematoma
Contusion
What are the types of a primary focal haematoma?
Extradural
Subdural
Intracerebral
What are the types of a primary focal contusion?
Coup contusion
Contre-coup contusion
What are the types of a primary diffuse head injury?
Concussion
Diffuse axonal injury
What are the types of traumatic head injury?
Open
Closed
What is an open traumatic head injury?
Something piercing the skull and dura, exposing the brain
What is a closed traumatic head injury?
The brain is not exposed
What are the causes of traumatic head injury?
Falls
Accidents
Abuse
Surgery
What are the types of non-traumatic head injury?
Infection
Stroke or TIA
Tumour
Metabolic disorder
What is a cerebral contusion?
Refers to head trauma causing brain to hit bony prominences in the skull or folds of dura
What does a contusion result in?
Micro-haemorrhages in the brain
Cerebral oedema, raised intracranial pressure, coma
What is a coup contusion?
Injury to brain at the site of impact
What is a contre-coup contusion?
Injury to brain on opposite side of impact, due to brain being physically shaken in the skull
What is a concussion?
Refers to head trauma causing stretching and injury of axons
What does a concussion result in?
Impaired neurotransmission
Loss of ion regulation
Reduction in cerebral blood flow
-all lead to temporary brain dysfunction
What is post-concussion syndrome?
Group of symptoms and signs due to the previous damage to the brain
What are some signs and symptoms of post-concussion syndrome?
Headache
Sensitivity to light or noise
Dizziness
Sleep disturbance
Difficulty concentrating
Difficulty remembering new information
What is diffuse axonal injury?
Shearing of interface between grey and white matter
What types of head trauma cause diffuse axonal injury?
Acceleration, deceleration or rotational injuries to the head
What is a complication of diffuse axonal injury?
Axonal death, cerebral oedema, raised intracranial pressure and then a coma
What is a basilar skull fracture?
Bony fracture in the base of the skull
What are the signs and symptoms of a basilar skull fracture?
Raccoon eyes
CSF otorrhea, meaning CSF leaks into middle ear
CSF rhinorrhea, CSF leaks from the nose
Battle sign
How does CSF leak out through the nose?
CSF leaks from middle ear through Eustachian tube into nasopharynx
Why does a basilar skull fracture give bruising?
Tears of dura and blood vessels
Why does a basilar skull fracture give CSF leakage?
Tears in meninges
How is a basilar skull fracture treated?
Elevation of depressed skull fractures
Control intracranial pressure
Persistent CSF leaks treated by surgery
Seek out and treat complications, likely to have other injuries due to amount of force required to break base of skull
What are the features of a mild head injury in terms of
- GCS score
- duration of post traumatic amnesia
- duration of loss of consciousness?
GCS score 13-15
Post-traumatic amnesia lasts less than 1 day
Loss of consciousness lasts less than half an hour
What are the features of a moderate head injury in terms of
- GCS score
- duration of post-traumatic amnesia
- duration of loss of consciousness
GCS score 9-12
Post-traumatic amnesia lasts less than a week
Loss of consciousness lasts less than 24 hours
What are the features of a severe head injury in terms of
- GCS score
- duration of post-traumatic amnesia
- duration of loss of consciousness
GCS score 3-8
Post-traumatic amnesia lasts more than a week
Loss of consciousness lasts more than 24 hours
What are the criteria for an urgent head CT scan?
GCS score less than 13 whenever
GCS score less than 14, two hours after head injury
Depressed skull fracture Focal neurological deficit Seizure when don’t usually have them Two or more episodes of vomiting Loss of consciousness and are above 65 or have coagulopathy or dangerous mechanism of injury, antegrade amnesia more than 30 minutes
What is antegrade amnesia?
Loss of memory of what has just occurred
Why is loss of consciousness and being above 65 an indication for urgent head CT scan?
Subdural haematoma more likely
Due to brain shrinking with age, increased tension on bridging veins, more likely to rupture
Why is loss of consciousness and coagulopathy an indication for an urgent CT head scan?
Taking warfarin and heparin gives increased risk of bleeding
