Week 3: Traumatic Brain Injury Flashcards
What are the types of acquired brain inury?
ABI are neurological changes which occur after birth.
- Traumatic brain injury (TBI)
- stroke
- hypoxic injury
- brain infection (meningitis)
- brain tumour
- neurodegenerative disorders
Define traumatic brain injury (TBI)
An insult to the brain caused by an external force that may produce diminished or altered states of consciousness.
e.g. car accident, falls, sporting accidents
In terms of the epidemiology of TBI, how many people experience it worldwide, in the US and in Aus p.a.?
50 million p.a. worldwide (50% TBIs over a lifetime)
1.4 m p.a. U.S.
1 in 45 Australians ( 5,480 new cases of mod-severe TBI).
What is the cost of TBI worldwide, in the US and in Aus anually?
$US 400 billion annually worldwide
$US 60 billion in US
$8.6 billion lifetime in AUS
these include treatment costs, loss of ability to contribute to the economy due to loss of ability to work , carers
True or false, TBI is the leading cause of death in children and young adult males and the leading cause of disability in those aged <40.
False.
leading cause of death for children only, not young adult males.
It is true that it is the leading cause of disability for those aged <40.
Which sex and age group experience the highest cases of TBI?
males more common - (males 2:5:1 females)
age group: 15-24 years and older adults
In terms of the pathophysiology of TBI, what are the two types of TBIs?
Open/ penetrating --> focal injuries - skull/ cranium is fractured exposing the brain - commonly involves penetration by a sharp object - e.g. Phineas Gage
Closed/ blunt –> focal & diffuse lesions
- fractures to the skull without penetration
- e.g. Subdural haematoma
Outline the primary mechanism of brain injury
result directly from physical trauma.
- biomechanical forces
- focal: direct impact, most likely to hit frontal & temporal lobes
- diffuse axon injury
What is diffuse axon injury?
acceleration and deceleration forces and rotation which leads to the shearing of axons, often resulting in loss of consciousness.
This is a primary mechanism of brain injury and it can be observed through diffusion tensor imaging (dFMRI).
Explain Coup-contrecoup injury
A coup injury occurs on the brain directly under the point of impact. A contrecoup injury occurs on the opposite side of the brain from where the impact occurred. Coup and contrecoup injuries are a type of traumatic brain injury that results in the bruising of the brain.
a counter- blow injury
Outline the secondary mechanism of brain injury
complications in occurring in the hours, weeks and months following the initial trauma.
What are the three types of secondary injury mechanisms?
Neurochemical - neuroprotective of neurotoxic cascades e.g. necrosis/ injury
Cellular - apoptosis
Physiological - hydrocephalus, infection, hypoxia, epilepsy
In terms of injury severity, __ % of TBIs are mild and __% of them are moderate.
In terms of injury severity, 80% of TBIs are mild and 10% of them are moderate.
How is injury severity classified ?
- duration of Loss of Consciousness (LOC)
- Glasgow Coma Scale (GCS) score –> degree of consciousness
- Duration of Post-Traumatic Amnesia (PTA)
- Results of CT Brain and MRI
What type of amnesia is NOT considered when measuring injury severity?
retrograde amnesia (forgetting events before the accident)
What is the LOC, GCS and PTA of mild brain injury?
LOC < than 30min
GCS 13-15
PTA < than 24hrs
What is the LOC, GCS and PTA of moderate brain injury?
LOC > than 30 but < than 24hrs
GCS 9-12
PTA 24hrs - 7 days
What is the LOC, GCS and PTA of severe brain injury?
LOC > than 24hrs
GCS 3-8
PTA > than 7 days
What are the 3 areas which the Glasgow Coma Scale measures?
Eye opening (E) (spontaneous) 4 - 1 (none)
Verbal Response (V) (Normal conversation) 5-1 (none)
Motor Response (M) (normal) 6 - 1 (none)
total = E+V+M, lower scores indicate lower levels of consciousness.
Define Post-Traumatic Amnesia
A period of confusion following a TBI. Some signs of PTA include, an inability to form new memories, disorientation, agitation.
e.g. being unable to remember their name & location
What is involved in the management of someone who is experiencing PTA?
- low stimuli environment e.g. quiet, no TV, consistent staff visits
- Avoidance of restraint and sedation
- frequent reassurance
- PTA monitoring.
How is PTA measured ?
Westmead P.T.A Scale.
- bedside assessment which tests orientation of a person experiencing PTA.
- e.g. how old are you, memory formation
What are the conditions for a person experiencing TBI to be discharged using the Westmead P.T.A Scale?
Patients must score 12 out of 12 for 3 consecutive days.
What are the three disorders of consciousness post TBI?
Brain death
- complete loss of brain function
- incompatible with life
Persistent vegetative state
- autonomic (brainstem) functions intact
- movements are reflexive/ automatic (e.g. can open eyes but can’t follow movement)
Minimally conscious state
- follow simple commands
- may use simple language (yes/no)
- smile
- reach for objects/ people
- track movement objects purposefully
- measured by Wessex Head Injury Matrix (WHIM)
