Traumatic Brain Injury Flashcards
Describe the pathophysiology of a subdural haemorrhage.
Occurs usually as a result of high-impact trauma, causing rupture on the bridging veins
Describe the presentation of an acute subdural haemorrhage.
Varies depending on the extent of bleeding - can range from incidental finding on CT or severe coma and coning.
What is first-line imaging for a head injury?
Non-contrast CT head
How does acute subdural haemorrhage appear on CT?
A hyperdense, crescentic lesion which is not limited by suture lines
A large haemorrhage could also cause mass effect, midline shift, and herniation
What is the management of acute subdural haemorrhage?
Small, incidental acute subdurals can be managed conservatively.
More severe and symptomatic acute subdurals may require emergency trauma craniotomy with a large flap for haematoma evacuation.
Cerebral swelling may require frontal or temporal lobectomy for decompression and bone flap removal.
Describe the presentation of chronic subdural haemorrhage.
Usually an elderly person or alcoholic.
Suspect chronic subdural in any individual with week-months history of fluctuating confusion, reduced consciousness, or neurological deficit.
How does chronic subdural haemorrhage appear on CT?
A hypodense, crescentic lesion which is not limited by suture lines.
What is the management for chronic subdural haemorrhage?
- Conservative management
- Non-surgical: dexamethasone 2mg TDS
- Surgical: haematoma evacuation via craniotomy or decompression with burr holes
Describe the pathophysiology of a extradural haemorrhage.
Usually occurs following low-impact trauma to the temporal area of the skull/pterion causing rupture of the middle meningeal artery.
Describe the typical presentation of extradural haemorrhage.
Typically younger people
“Walk and die”
Initially, brief loss of consciousness (~30s), followed by a lucid period and then a rapid decline in GCS
May have fixed, dilated pupils
Why might a person with EDH have fixed, dilated pupils?
Expansion of the haematoma causes compression of the parasympathetic fibres of CN III
How does EDH appear on CT head?
A hyperdense, biconvex lesion which does not cross suture lines
How should EDH be managed?
Usually considered a neurosurgical emergency
Burr hole over pterion, followed by craniotomy and evacuation of haematoma
Describe the pathophysiology of a subarachnoid haemorrhage.
Sudden rupture of an intracranial (berry) aneurysm, rupture of AVMs, pituitary apoplexy, or trauma
Which conditions are associated with an increased risk of SAH?
Any condition associated with berry aneurysms:
- ADPKD
- Ehlers-Danlos syndrome
- Aortic coarctation
How does SAH usually present?
- Thunderclap headache
- Meningism –> headache, photophobia, neck stiffness
- N+V
- Seizures
- Coma
How does SAH appear on CT head?
“Star sign” - hyperdensities within the basal cisterns, sulci, and ventricular systems
If CT head is negative for SAH, what investigation should be performed?
LP at 12 hours following symptom onset.
Looking for xanthochromia (RBC breakdown)
How should SAH be managed?
- Interventional neuroradiologist: coiling
- Neurosurgery: clipping
- 21-day course of nimodipine
What is nimodipine and why is it given in SAH?
- CCB
- Given to prevent vasospasm and rebleeding following SAH
What are the potential complications of SAH?
- Rebleeding (most common in first 12h)
- Vasospasm
- Hyponatraemia –> SIADH
- Seizure
- Hydrocephalus
- Death
What are the indications for immediate CT head (adults)?
- GCS <13
- GCS <15 2 hours from injury
- Suspected open or depressed skull fracture
- Signs of basal skull fracture
- Post-traumatic seizures
- Focal neurological deficit
- > 1 episode of vomiting
- Bleeding disorder/anticoagulation
What are the indications for CT head within 8h (adults)?
- Amnesia or LOC (and none of the immediate CT indications)
- Age >65 years
- Dangerous mechanism of injury
What are the criteria for admitting head injury patients to hospital?
- New abnormalities on imaging
- GCS <15 (even if imaging is normal)
- Persistent vomiting or severe headache
- Fits criteria for CT head at 8 hours
- Any other concerns such as drugs, alcohol intoxication, other injuries, shock, meningism, CSF leak, non-accidental injury
