Lecture 13: Traumatic Brain Injury Flashcards
1
Q
A little history
A
- Recognition hundreds of years ago that there is a relationship between brain & mind/behaviour
- Numerous famous single cases in history which have shaped understanding of brain functions
2
Q
Phineas Gage (1823-60)
A
- Destroyed left frontal lobe
- Reported effects on personality + behaviour
- Influenced mind-brain discussions of that time
- Suggested that localized brain damage can affect personality
3
Q
H.M (1926-2008)
A
- Suffered intractable epilepsy = from L&R temporal lobes
- Underwent radical neurosurgery with bilateral removal of parts
- Epilepsy reduced
- But had severe retrograde amnesia
- Unable to make new memories post-surgery
- Some retrograde amnesia
- Impairments in explicit/episodic memory
- Some evidence of reduced ability to make new semantic memories
- WM intact
- Contribution to understanding of how memory is organised in the brain
- Other cognitive functions largely unaffected
4
Q
Lateralisation of cognitive processes
A
- Grammar, vocab, literal meaning = usually LH
- Language production = LH for most right-handed people but bilateral or right H for left-handed
- Bilateral = processing of stimuli, spatial manipulation, facial perception, artistic ability
- Bilateral parietal = comparison, online calculation
- Left parietal = exact calculation, fact retrieval
5
Q
TBI in NZ
A
- BIONIC study
- All cases of TBI between Mar 2010-Feb 2011 were registered
- Total TBI incidence: 790 per 100,000 persons/year
- mTBI incidence: 749 per 100,000
- Mod-severe TBI: 41 per 100,000
- TBI affected boys/men > girls/women
- Maori people had greater risk of mTBI than European people
- Incidence of mod-sev TBI in rural population was 2.5x > than urban pop
- Younger people almost 70% of all TBI cases
6
Q
TBI
A
- WHO: an acute brain injury resulting from mechanical energy to head from external physical forces
- Open head injury = object pierces the skull + dura mater
- Closed head injury = brain is not exposed
7
Q
TBI Pathology
A
- Diffuse injury - Oedema (swelling)
- Diffuse Axonal Injury (DAI) = axonal damage
= might include white matter tracts in cortex
= concussion/mTBI
8
Q
TBI Pathology: Focal injury
A
- Contusions = bruising of brain tissue, multiple microbleeds, blood mixed amongst brain tissue, often in orbitofrontal & anterior temporal regions
- Coup-contrecoup injury = coup: injury on side of impact
= contrecoup: injury on opposite side of impact
= brain moving inside skull - Haematomas = collections of blood in brain from a haemorrhage
- Haemorrhages = active bleeding within brain tissue
9
Q
Places of bleeding
A
- Intracerebral = bleeding within brain tissue
- Epidural = between skull & dura mater
- Subdural = between dura & arachnoid membrane
- Subarachnoid = between arachnoid & pia mater
- Intraventricular = bleed in ventricles
10
Q
Primary injury
A
Occurs at time of trauma = immediate tissue damage
11
Q
Secondary injury
A
- Occurs mins to days after initial trauma
- Damage to blood brain barrier
- Blood flow changes in brain
- Ischaemia (insufficient blood flow)
- Hypoxia (insufficient oxygen)
- Oedema
- Raised intracranial pressure (due to swelling or from bleeding)
- Herniation of brain tissue
12
Q
Severity Indicators
A
1) mTBI/Concussion: GCS (13-15) PTA (24hrs or less) Loss of consciousness (0-30 min) 2) Moderate TBI: GCS (9-12) PTA (1-6 days) LoC (>30min, <24hrs) 3) Severe TBI: GCS (8 or less) PTA (7 days or more) LoC (>24hrs)
13
Q
Glasgow Coma Scale
A
- Best eye response
- Best verbal response
- Best motor response
14
Q
Westmead Post-Traumatic Amnesia Scale
A
- Duration is from time of accident until first day of 3 consecutive days in which individual achieves score of 12/12
= patients can make continuous memories rather than having ‘islands’ of memories
15
Q
Sequelae of moderate/severe TBI
A
- Depends on injury severity, location(s) & type(s) of lesions
- Physical, cognitive, behavioural, mood
