Head Injury Flashcards
Define TBI [1]
A non-degenerative, non-congenital insult to the brain from an external mechanical force, possibly leading to permanent or temporary impairment of cognitive, physical and psychosocial functions, with an associated diminished or altered state of consciousness
TBI injury mechanism:
What are the 3 causes of TBI? [3]
Penetrating injury
* Foreign object (e.g. bullet) enters into brain causing focal damage.
Closed head injury:
* Blow to the head (e.g. road traffic accident).
Blast injury
* Explosion (e.g. bomb) create fast moving pressure wave that passes through the brain and damages axons and vasculature.
Name 5 reasons can have closed head injury [5]
1- Skull fracture
2- Contusion (bruise)
3- hematomas (blood clots)
4- lacerations (tear)
5- Diffuse axonal injury (nerve damage)
Types of traumatic brain injury injury classification
Describe the injury classifications for TBI [2]
Focal injury:
- Coup: at site
- Contrecoup: opposite site
Diffuse injury:
- Diffuse axonal injury
Diagnosis of TBI
Which scale is used to classify TBI? [1]
Which criteria is it based on? [3]
What is the maximum score for each of the criteria? [1]
Glasgow Coma Scale (GCS):
Based on:
- eye opening [/4]
- motor response [/5]
- verbal response [/6]
What are mild, moderate and severe GCSs? [3]
Mild: 14-15
Moderate: 9-13
Severe: less than 8
Explain the two other scales that can be used to assess TBI? [2]
Loss of Consciousness (LOC) scale measures the time patient was unconscious
Post traumatic amnesia (PTA) scale measures the interval from injury until patient is orientated and can form and recall new memories.
.
Diagnosis of TBI: Imaging
What type of imaging is used for triaging TBI? [1]
Non-enhanced head Computerized tomography (CT) scan is used for triage.
Diagnosis of TBI: Imaging
What GCS would cause a CT to be given:
- straight away? [1]
- after 2 hrs of assessment [1]
GCS less than 13 on intial assessment
GCS less than 15 after 2 hours of injury assessment
Basal skull fractures have at least one of which signs? [4]
- CSF coming out of ear
- blood behind ear drum
- raccoon eyes.
- Hemotympanum (blood in ear drum)
(However, takes approx. a day to appear-earliest in a couple of hours)
Diagnosis of TBI Imaging
What type of imaging would be used if unexplained neurological findings with normal CT scan ? [1]
MRI scan has greater sensitivity to detect more subtle injury
Name 3 issues of using MRI for TBI imaging [3]
- MRI scan not suitable for patients will metal implants (e.g. dental fillings, aneurysm clips), pacemaker or bullet injury (potential metal fragments).
- Patient needs to remain motionless for long period due to long imaging time.
- Higher cost than CT scan.
What can an MRI scan detect that a CT scan cannot? [3]
- diffuse axonal injury ( the shearing (tearing) of the brain’s long connecting nerve fibers (axons) that happens when the brain is injured as it shifts and rotates inside the bony skull)
- non-haemorrhagic contusion
- brainstem injury
1- Pathophysiology of TBI
Explain how brain tissue can be physically damaged directly from TBI [2]
Contusion (is a bruise to a specific area of the brain caused by an impact to the head; also called coup or contrecoup injuries)
Gunshot head injury
1- Pathophysiology of TBI: Increase in intracranial pressure
ICP occurs from which parts of brain fluids? [2]
CSF
Cerebral blood flow
1- Pathophysiology of TBI: Increase in intracranial pressure
How do you detect ICP? [1]
ICP bolt
1- Pathophysiology of TBI: Increase in intracranial pressure
Describe the Monro-Kellie Hypothesis [4]
Relationship between the contents of the cranium and intracranial pressure:
- Brain is enclosed in a fixed non-expandable skull.
- Increase in mass (e.g. haematoma) reduces CSF and cerebral blood flow in the brain.
- Decrease in brain blood and CSF causes ischemia and then brain cell death.
- Increase ICP can cause herniation.
Pathophysiology of TBI (increase intracranial pressure)
What is normal ICP [1]
Was can a ICP of greater than cause herniation? [1]
Normal adult ICP: 5 - 15 mmHg (supine position).
A mass lesion with an ICP of ≥ 20 mmHg can cause herniation.
3- Pathophysiology of TBI: herniation
Name the 6 types of brain herniation
Uncal
Central (transtentorial)
Cingulate (Subfalcine)
Transcalvarial
Upward cerebellar (transtentorial)
Downward cerebellar (Tosillar)
3- Pathophysiology of TBI (severe brain injury)
What is the difference between decorticate and decerebrate brain injury location and presentation? [4]
Decerebrate: damage to midbrain, brainstem and/or pons – anything below the red nucleus .
Decorticate: damage to cerebral cortex and/or internal capsule.
4- Pathophysiology of TBI (haematoma)
What are the 4 types of haematoma [4]
Epidural haematoma (EDH)
Subdural haematoma (SDH)
Subarachnoid haematoma (SAH)
Intracerebral haematoma (ICH)
4- Pathophysiology of TBI (haematoma)
Label A-D
A: SDH = subdural haematoma
B: EDH = epidural haematoma
C: IPH = intraparenchymal haemorrhage
D: SAH = subarachnoid haemorrhage
Which of the following is most likely to occur to a young adult with a skull fracture?
A: SDH = subdural haematoma
B: EDH = epidural haematoma
C: IPH = intraparenchymal haemorrhage
D: SAH = subarachnoid haemorrhage
A: SDH = subdural haematoma
B: EDH = epidural haematoma
C: IPH = intraparenchymal haemorrhage
D: SAH = subarachnoid haemorrhage
Epidural haematoma occurs from damage to which artery? [1]
How does it classically present in imaging? [1]
EDH is mostly from damage middle meningeal artery (75%)
EDH is often in CT scan as ‘lemon’/biconvex shape and can cause herniation.
Epidural haematoma occurs from damage to which artery? [1]
How does it classically present in imaging? [1]
EDH is mostly from damage middle meningeal artery (75%)
EDH is often in CT scan as ‘lemon’/biconvex shape and can cause herniation.
4- Pathophysiology of TBI (Sub Dural Haemotmoa)
Which layers do SDH occur in? [1]
Which blood vessel is commonly affected? [1]
How does SDH commonly occur in imaging?
Subdural haematoma (SDH) is a blood clot in the subdural space between the dura and arachnoid mater of the meninges.
SDH is mostly from damage bridging cortical veins (75%)
SDH is often in CT scan as ‘banana/crescent’ shape and can cause herniation.
4- Pathophysiology of TBI (traumatic SAH)
Between which parts of the brain are effected in SAH? [1]
SAH typically occur due to damage to which structure? [1]
SAH: between the dura and arachnoid mater of the meninges
SAH is more common from damage in cerebral sulci than Sylvian/lateral fissure or basal cisterns.
4- Pathophysiology of TBI Intracerebral haematoma
ICH is a blood clot in which layers of brain? [1]
What does ICH appear like on imaging? [1]
Intracerebral haematoma (ICH) is blood clot in the parenchyma (cellular tissue) of the brain.
4- Pathophysiology of TBI (seizures)
What is a seizure due to? [1]
What is the difference in time between Early and Late Post Traumatic seizures? [2]
Seizures are abnormal sudden electrical disturbance in the brain.
Early post-traumatic seizures: A seizure within 1st week of TBI.
Late post-traumatic seizures: A seizure after 1st week of TBI.
4- Pathophysiology of TBI (seizures)
What is a seizure due to? [1]
When can seizures occur post-TBI? [2]
Seizures are abnormal sudden electrical disturbance in the brain.
Early post-traumatic seizures: A seizure within 1st week of TBI.
Late post-traumatic seizures: A seizure after 1st week of TBI.
5- Acute management of TBI (Mild TBI)
How would you acutely treat mild TBI? [2]
5- Acute management of TBI (Mild TBI)
How would you acutely treat moderate TBI?
(Moderate TBI: Experience brain changes and symptoms remains or worsen)
- Transfer to Neurosurgical unit
- Surgical evacuation dependent on size and type of haematoma
- Transfer to intensive care unit (ICU) to allow brain bruising + swelling to reduce by itself.
What size haematoma would be evacuated regardless of GCS? [1]
>30 cm3
5- Acute management of TBI (Severe TBI)
Which drugs can you use to start seizure prophylaxis? [2]
Which drugs can you use to induce coma? [2]
Start on seizure prophylaxis: phenytoin/levetiracetam
Sedation/Induce coma with propofol or benzodiazepines
5- Acute management of TBI (Severe TBI)
If have a patient on warfarin with TBI, what should you give [2] and why? [1]
Elderly patient on warfarin (ischemic stroke prevention in atrial fibrillation) with TBI should undergo rapid (<2 h) reversal of warfarin with fresh frozen plasma and vitamin K to avoid intracranial haemorrhage.
5- Acute management of TBI (Severe TBI - ICP)
How could you manage severe ICP:
Acutely [2]
Long term [1]
Short term:
* mannitol
* hypertonic saline
(shift of water from extravascular space to intravascular space across the BBB-controversy which therapy is better.)
Long term:
* extraventricular drain/ external ventricular drain (EVD) or ventriculostomy
