S10) Head Trauma and Acute Intracranial Events Flashcards
How can one classify different head injuries?
How can one classify different traumatic head injuries?
What is a cerebral contusion?
A cerebral contusion is the bruising of the brain whereby blood mixes with cortical tissue due to microhaemorrhages and small blood vessel leaks
In six steps, describe the pathophysiology of cerebral contusion
⇒ Trauma
⇒ Microhaemorrhages
⇒ Cerebral contusion
⇒ Cerebral oedema/Intracerebral bleed
⇒ Raised ICP
⇒ Coma
What is a concussion?
A concussion is a head injury with a temporary loss of brain function
In four steps, describe the pathophysiology of a concussion
⇒ Trauma
⇒ Stretching and injury to axons
⇒ Impaired neurotransmission, loss of ion regulation, ↓cerebral blood flow
⇒ Temporary brain dysfunction
Describe some features of post concussion syndrome
- Sleep disturbance
- Emotional/mood changes
- Thinking/remembering difficulties
- Physical symptoms (headaches, nausea, dizziness)
What is diffuse axonal injury?
Diffuse axonal injury is the shearing of the interface between grey and white matter following traumatic acceleration/deceleration or rotational injuries to the brain damaging the intra- cerebral axons and dendritic connections
In six steps, describe the pathophysiology of a diffuse axonal injury
⇒ Trauma
⇒ Shearing of grey and white matter interface
⇒ Axonal death
⇒ Cerebral oedema
⇒ Raised ICP
⇒ Coma
What is a basilar skull fracture?
A basilar skull fracture is a bony fracture within the base of skull (temporal, occipital, sphenoid or ethmoid bone)
In three steps, describe the pathophysiology of a basilar skull fracture
⇒ Trauma
⇒ Tears in the meninges
⇒ CSF leakage
Identify six signs of a basilar skull fracture
Outline the management for a basilar skull fracture
- Traumatic brain injury management (incl ICP control)
- Seek and treat complications
- Elevation of depressed skull fractures
- Persistent CSF leak management → surgery
Indicate the three factors which determine whether a traumatic head injury is mild, moderate or severe
How does an EDH present on a CT head scan?
What are the urgent CT head criteria relating to consciousness?
- GCS < 13 at any point
- GCS < 14 2/more hours after injury
What are the urgent CT head criteria relating to neurological abnormalities?
- Focal neurological deficit
- Seizure
- Loss of consciousness with any of: age >65, coagulopathy, dangerous mechanism of injury, antegrade amnesia >30 minutes
Apart from consciousness and neurological abnormalities, what are the other urgent CT head criteria?
- Suspected open/depressed skull fracture
- Signs of basal skull fracture
- 2+ discrete episodes of vomiting
What is an extradural haemorrhage?
- An extradural haemorrhage is the collection of blood between inner surface of the skull and the periosteal dura mater
- It is nearly always secondary to trauma and/or skull fracture and most commonly occurs due to a severed middle meningeal artery
In three steps, describe how levels of consciousness vary in extradural haemorrhages
⇒ Patient will present with LOC due to impact of initial injury
⇒ Followed by transient recovery with ongoing headache known as a ‘lucid interval’ (40% of patients)
⇒ Haematoma enlarges and ↑ ICP causing compression of the brain and rapidly deteriorating level of consciousness
The prognosis of EDH is generally good with early intervention.
Describe the management for small and large EDH respectively
- Small EDH can be observed and managed conservatively with neurological follow up
- Large EDH require referral to neurosurgery for craniotomy and clot evacuation
Identify 6 complications of extradural haemorrhages
- Permanent brain damage
- Coma
- Seizures
- Weakness
- Pseudoaneurysm
- Arteriovenous fistula
What is a subdural haemorrhage?
- A subdural haemorrhage is the collection of blood between meningeal dura mater and the arachnoid mater
- Bleeding occurs due to shearing forces on cortical bridging veins
How might the presentations of SDHs vary chronologically?
- Acute (<3 days)
- Subacute (3-21 days)
- Chronic (>3 weeks)
How does an acute SDH present on a CT head scan?
How does a chronic SDH present on a CT head scan?
The prognosis of SDH is a lot poorer than EDH.
Describe the management for chronic and acute SDH respectively
- Small chronic SDH can be evaluated with serial imaging
- Acute SDH need immediate neurosurgical intervention to relieve raised ICP
- Symptomatic subacute/chronic SDH are often treated via one or more burr hole
Compare and contrast the different presentation of EDHs and SDHs on CT head scans
- EDH – lentiform / biconcave
- SDH – crescent / sickle
What is a subarachnoid haemorrhage?
- A subarachnoid haemorrhage is a collection of blood between arachnoid mater and the pia mater
- Vast majority of SAH occurs spontaneously, secondary to ruptured berry aneurysm (may also be traumatic)
Identify six clinical symptoms of subarachnoid haemorrhages
- Sudden onset ‘thunderclap’ headache
- Meningism
- Nausea & vomiting
- Fever
- Focal neurological deficits
- LOC
Identify some sites of aneurysm formation for SAHs
Do berry aneurysms present with symptoms?
Berry aneurysms are largely asymptomatic but symptoms may arise if compressing on nearby structures or during early stages of rupture
What are the risk factors for berry aneurysms?
- Family history
- Hypertension
- Heavy alcohol consumption
- Abnormal connective tissue (Ehlers-Danlos, Marfan’s Disease)
How does a SAH present on a CT head scan?
Explain how a lumbar puncture aids the diagnosis of an SAH
Lumbar puncture performed to aid diagnosis:
- Presence of RBCs (same number in 3 bottles)
- Xanthochromia (within 12 hours after symptom onset)
Describe the five steps in the clinical management of subarachnoid haemorrhages
⇒ Stabilise the patient
⇒ Prevent rebleeding
⇒ Treat cerebral vasospasm
⇒ Correct hyponatraemia
⇒ Neurosurgical intervention (if large bleed)
What does the prognosis of an SAH depend on?
Prognosis depends on GCS, degree of neurological deficit at the time of presentation and comorbidities
Identify six complications of SAHs
- Hydrocephalus
- Focal neurological deficits
- Coma
- Seizures
- Cognitive decline
- Frequent headaches
