Traumatic Brain Injury Flashcards
Where is the bleed in an extradural haematoma?
The extradural space, between the dura and the inner skull
Extradural haematoma can also be known as what?
Epidural haematoma
Which gender is more likely to be affected by extradural haematoma? In what age demographic is this usually seen?
Males (4:1) / Younger adults
What is the commonest cause of an extradural haematoma?
A skull fracture at the pterion, leading to rupture of the MMA beneath it
What is the major clinical feature of an extradural haematoma?
Transient loss of consciousness and then recovery (resulting in a lucid interval)
During the lucid interval of an extradural haematoma there is continued bleeding, what is the result of this?
Bleeding overcomes the body’s ability to compensate, leading to raised ICP causing headache and nausea/vomiting
What happens at the end of the lucid interval in extradural haematoma?
There is a decrease in conscious level resulting in drowsiness and reduced GCS
Eventually in extradural haematoma, brain herniation develops. Which is the most common type?
Tentorial (uncal)
What features will a tentorial/uncal herniation as a result of extradural haematoma result in?
Ipislateral fixed dilated pupil and contralateral hemiparesis
What can extradural haematoma lead to if left untreated?
Coma, tonsillar herniation and cardiorespiratory arrest
What is the first line investigation for suspected extradural haematoma?
CT
Describe the haemorrhage seen on CT scan of an extradural haematoma?
Hyperdense, biconvex, limited to the suture lines of the inner surface of the skull
What is the commonest location of an extradural haematoma on imaging?
The frontotemporal region
What is the best treatment for extradural haematoma?
Surgical evacuation
If a patient with extradural haematoma is in a coma, has signs of herniation and is waiting for surgical review, what are some measures that can be taken?
Give mannitol and hyperventilation
Delay in treatment of an extradural haematoma can lead to what?
Death or severe disability
What are the most common mechanisms of injury of an extradural haematoma?
Acceleration-deceleration injury, blow to the side of the head
What are the two key features of an extradural haematoma?
Lucid interval and raised ICP
Where is the bleed in a subdural haematoma?
In the subdural space, between the dura and arachnoid mater
What factors differentiate subdural haematomas into acute, subacute and chronic?
The time (days) since the injury, and the CT appearance
What are the two main causes of an acute subdural haematoma and who do they occur in?
Younger patients following an RTA, and elderly patients after a fall
Which represents more severe trauma and damage to the brain - an extradural or subdural haematoma?
Subdural
Acceleration-deceleration injuries are a common cause of subdural haematoma, what is the reason behind this?
Trauma causes haemorrhage by tearing bridging veins that transverse the subdural space
What defines an acute subdural haematoma?
0-5 days since the injury, hyperdense appearance on CT
How do most patients with an acute subdural haematoma present?
In a coma
What are the CT features of an acute subdural haematoma?
Hyperdense, crescent shape, not limited by suture lines of the skull, may have signs of other intracranial injury
When is evacuation of acute subdural haematoma recommended?
If there is a diameter of > 10mm or > 5mm of midline shift
What post-operative care is often required for an acute subdural haematoma?
ICP monitoring and control in neuro ICU
Acute subdural haematoma may occur with relatively minor trauma in patients on what medication?
Warfarin
Where do acute subdural haematomas most commonly occur?
Frontal/parietal lobes
Which has a quicker onset of symptoms - extradural or subdural haematomas?
Extradural
What is a chronic subdural haematoma?
A subdural bleed which has liquified over weeks
What defines a chronic subdural haematoma?
> 21 days since the injury, hypodense CT appearance
Who does chronic subdural haematoma usually occur in?
Elderly patients
Apart from increased age, what are some risk factors for chronic subdural haematoma?
Alcoholism, anti-coagulant use, coagulation disorder, frequent falls
How do patients with chronic subdural haematoma present?
Features of raised ICP +/- focal neurological deficits
What are some CT features of chronic subdural haematoma?
Hypodense, crescent shaped, significant mass effect and midline shift
When is treatment indicated for chronic subdural haematoma?
If there is severe headache or focal neurological deficits
How is chronic subdural haematoma treated?
Correction of underlying coagulopathy if indicated, followed by surgical evacuation
