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)
Describe neurological sequelae/ symptoms after TBI
- fatigue, drowsiness, sleep changes
- chronic pain, headache
- seizures
- orthopaedic injuries
Describe the motor and sensory symptoms post TBI
- damage to primary motor cortex or motor tracts
- difficulty with speech or swallowing
- dyspraxia - motor programming difficulties
- dizziness, nausea balance and gait problems
- sensitivity to noise and light
- loss of smell (anosmia) or taste
- loss of sensation
Describe cognitive and communication sequelae
- attention dysfunction
- reduced processing speed
- trouble with memory and learning (particularly in the case of diffuse axon injury)
- executive dysfunction - problem solving, planning , time management
communication changes:
- receptive & expressive language impairments
- tangential/ verbose
- difficulty with nonverbal and pragmatic language
Describe psychological sequelae
- poor emotional regulation
- loss of self-esteem and self efficacy
- 60% developed psychiatric disorder in the first year after moderate/ severe TBI
- 40%% developed mood & anxiety disorders, 30% MDD, 12.7% PTSD and Anxiety disorders 35.3%
- higher rates of suicide (4x rate)
- increase in alcohol use 2nd year after TBI
Explain the organic reasons why mental health disorders develop after TBI
- frontal and temporal lobes and limbic system are commonly injured –> involved in emotions
- flattened affect, emotional liability, irritability, reduced frustration, tolerance, ego-centricity, suspiciousness and apathy
Explain the reactive reasons why mental health disorders develop after TBI
- emotional changes occur in response to the experience of functional disability
- e.g. reduced self-esteem, identity-crisis, loneliness
Describe behavioural sequelae
- irritability, impulsivity
- aggression
- inappropriate social and sexual behaviour
- reduced initiation - e.g. need prompting to shower, eat etc
- perseveration
- wandering/ absconding
List the psychosocial outcomes
- occupational activities (difficulties returning to work or study)
- interpersonal relationships
- independent living skills (domestic tasks, self care)
Paediatric TBI common causes
- falls
- bicycle accidents
- head strikes (balls)
Paediatric TBI differences between adults and children
- skull flexibility (softens the impact of the fall)
- head size/weight
- potential for plasticity
- vulnerability of later development
Outline the role of neuropsychologists in TBI rehabilitation
- assessing injury severity, cognitive strengths & weaknesses
- monitoring recovery
- cognitive rehabilitation
- psychological support for person and family
- behaviour intervention
- providing opinion on capability to return to work, driving, independent living
Describe the restorative approach to cognitive rehabilitation
Attempts to restore cognitive functions
Describe the compensatory approach to cognitive rehabilitation
Modification of tasks to compensate for cognitive difficulties
e.g. calendars & lists, reducing external distractions, avoid sarcasm,
