Traumatic brain injury Flashcards
What is traumatic brain injury?
Acquired disruption of the normal function or structure of the brain caused by.a head impact or external force
What type of trauma can cause traumatic brain injuries?
- Blunt trauma
- Penetrating injuries
- Blast injuries
- However not all impacts to the head cause TBI
According to the WHO how do you classify mild TBI?
Mild TBI is due to a blunt or mechanical force that results in some type of transient confusion, disorientation, or loss of consciousness lasting not more than 30 minutes; is possibly associated with transient neurobehavioural deficits; and has a Glascow Coma Scale (GCS) score no lower than 13.
some pts may intially present with none of these
How do you classify TBI based on GCS?
Mild TBI: GCS 13-15; mortality 0.1%
Moderate TBI: GCS 9-12; mortality 10%
Severe TBI: GCS <9; mortality 40%.
How do you classify TBI based on mechanism?
- Blunt TBI: external mechanical force leads to rapid acceleration or deceleration with brain impact. Blunt TBI is typically found in the setting of motor vehicle-related injury, falls, crush injuries, or physical altercations.
- Penetrating TBI: occurs when an object pierces the skull and breaches the dura mater, seen commonly in gunshot and stab wounds.
- Blast TBI: commonly occurs after bombings and warfare, due to a combination of contact and inertial forces, overpressure, and acoustic waves
How do you classify TBI by area of brain involvement
- Diffuse brain injury includes diffuse axonal injury (DAI), hypoxic brain injury, diffuse cerebral oedema, or diffuse vascular injury.
- Focal injury includes specific lesions such as contusions, intracranial haematomas, infarctions, axonal tears, cranial nerve avulsions, and skull fractures.
both types often co-exist
What is primary injury in TBI?
what are some examples
- Due to the immediate mechanical force
- May incl the following
Concussion
Skull fracture
Contusion (localised punctate haemorrhages)
Haematoma: Subdural, epidural, intracerebral
Subarachnoid haemorrhage
Axonal shear or laceration
What is secondary injury in TBI?
- Evolving pathphysiological consequences of the primary injury
- May incl the following:
Cerebral oedema
Increased intracranial pressure
Haemorrhage progression
Seizures
Ischaemia
Infection
Traumatic venous sinus thrombosis.
What are the symptoms of concussion?
- short-lived confusion
- disorientation
- loss of consciousness, with or without neurobehavioural deficits.
- headache
- vestibular deficit
- Occur in most pts with TBI, typically the only findings in pts with mild TBH
What is post concussive syndrome?
the presence of 3 or more of the following symptoms after a head injury:
* headache,
* dizziness,
* fatigue,
* irritability,
* difficulty with concentrating and performing mental tasks, i
* mpairment of memory,
* insomnia
* reduced tolerance to stress, emotional excitement, or alcohol
When do you CT for a ?TBI?
Adults
For people 16 and over who have sustained a head injury, do a CT head scan within 1 hour of any of these risk factors being identified:
- a GCS score of 12 or less on initial assessment in the emergency department
- a GCS score of less than 15 at 2 hours after the injury on assessment in the emergency department
- suspected open or depressed skull fracture
- any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign)
- post-traumatic seizure
- focal neurological deficit
- more than 1 episode of vomiting
For people 16 and over who have had some loss of consciousness or amnesia since the injury, do a CT head scan within 8 hours of the head injury, or within the hour in someone presenting more than 8 hours after the injury, if they have any of these risk factors:
- age 65 or over
- any current bleeding or clotting disorders
- dangerous mechanism of injury (a pedestrian or cyclist struck by a motor vehicle, an occupant ejected from a motor vehicle or a fall from a height of more than 1 m or 5 stairs)
- more than 30 minutes’ retrograde amnesia of events immediately before the head injury.
https://www.nice.org.uk/guidance/ng232/chapter/Recommendations#investigating-clinically-important-traumatic-brain-injuries
When do you CT for a ?TBI?
Child
For people under 16 who have sustained a head injury, do a CT head scan within 1 hour of any of these risk factors being identified:
* suspicion of non-accidental injury
- post-traumatic seizure
- on initial emergency department assessment, a GCS score of less than 14 or, for babies under 1 year, a GCS score (paediatric) of less than 15
- at 2 hours after the injury, a GCS score of less than 15
- suspected open or depressed skull fracture, or tense fontanelle
- any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign)
- focal neurological deficit
- for babies under 1 year, a bruise, swelling or laceration of more than 5 cm on the head.
For people under 16 who have sustained a head injury and have more than 1 of these risk factors, do a CT head scan within 1 hour of the risk factors being identified:
*
- loss of consciousness lasting more than 5 minutes (witnessed)
- abnormal drowsiness
- 3 or more discrete episodes of vomiting
- dangerous mechanism of injury (high-speed road traffic accident as a pedestrian, cyclist or vehicle occupant, fall from a height of more than 3 m, high-speed injury from a projectile or other object)
- amnesia (anterograde or retrograde) lasting more than 5 minutes (it will not be possible to assess amnesia in children who are preverbal and is unlikely to be possible in children under 5)
- any current bleeding or clotting disorder.
How may an extradural haemorrhage present?
- may or may not have a lucid interval
- Reduced GCS
- Headache
- Cranial N. III–> Blown
- Coning–> Cushings Triad (HTN, bradycardia and irregular breathing- in that order)
How do you manage Extradural haemorrhage?
- Definitive treatment: SURGERY
- Mannitol/ 5% hypertonic saline–> reduces cerebral pressure–> reduces swelling. Need catheter to keep bladder empty
- Position pt to 30/40 degrees to encourage venous drainage
- Keep all obs normal, CO2 at the lower end of normal
Subdural haemorrhage risk factors?
Old age
coagulopathy/ anticoag use
alcholism
