Lecture 13: Traumatic Brain Injury

Question 1

A little history

Answer 1

• 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

Question 2

Phineas Gage (1823-60)

Answer 2

• Destroyed left frontal lobe
• Reported effects on personality + behaviour
• Influenced mind-brain discussions of that time
• Suggested that localized brain damage can affect personality

Question 3

H.M (1926-2008)

Answer 3

• 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

Question 4

Lateralisation of cognitive processes

Answer 4

• 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

Question 5

TBI in NZ

Answer 5

• 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

Question 6

TBI

Answer 6

• 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

Question 7

TBI Pathology

Answer 7

• Diffuse injury - Oedema (swelling)
• Diffuse Axonal Injury (DAI) = axonal damage
  = might include white matter tracts in cortex
  = concussion/mTBI

Question 8

TBI Pathology: Focal injury

Answer 8

• 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

Question 9

Places of bleeding

Answer 9

• Intracerebral = bleeding within brain tissue
• Epidural = between skull & dura mater
• Subdural = between dura & arachnoid membrane
• Subarachnoid = between arachnoid & pia mater
• Intraventricular = bleed in ventricles

Question 10

Primary injury

Answer 10

Occurs at time of trauma = immediate tissue damage

Question 11

Secondary injury

Answer 11

• 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

Question 12

Severity Indicators

Answer 12

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)

Question 13

Glasgow Coma Scale

Answer 13

• Best eye response
• Best verbal response
• Best motor response

Question 14

Westmead Post-Traumatic Amnesia Scale

Answer 14

• 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

Question 15

Sequelae of moderate/severe TBI

Answer 15

• Depends on injury severity, location(s) & type(s) of lesions
• Physical, cognitive, behavioural, mood

Question 16

Sequelae of mTBI/concussion

Answer 16

Physical, mood, behavioural, cognitive

Question 17

mTBI vs. Post-Concussion Syndrome

Answer 17

• Most mTBI/C symptoms resolve in 3 months or so
• Occasionally, symptoms persist much longer = ‘post concussion syndrome’
• Contentious diagnosis = is it structural brain damage or functional/psychological/medication/mood-related or combo of both?

Question 18

What is clinical neuropsychology?

Answer 18

• An applied science concerned with behavioural expression of brain dysfunction
• Brain pathology & resulting symptoms
• Psychological interest in analysis of higher functions in normal mind to develop better understanding in damaged brain
• A neuropsychological assessment of: cognitive functioning, mood, behaviour

Question 19

NP Ax procedure

Answer 19

• Review referral notes
• Initial clinical interview = referral Qs, cognition, client’s goals etc.
• Neuropsych Assessment session
• Scoring/interpretation
• Collateral info
• Report writing
• Feedback sessions

Question 20

Interview

Answer 20

• Informed consent
• Explain reason for assessment, results, confidentiality, importance of effort
• Build therapeutic alliance
• Capture valid representation of thinking abilities
• Qualitative observation of how person responds to tests

Question 21

Cognitive Domains

Answer 21

• Attention = WM, sustained A
• Processing speed
• General verbal abilities = lang. comprehension, semantics
• General visuospatial abilities = spatial awareness, object use
• Memory = encoding & retrieving info
• Executive functioning = planning, problem-solving

Question 22

Test development & interpretation

Answer 22

• Test development = to create a relatively ‘pure’ measure of each cognitive domain
• Goal is to work out where person’s areas of strength + difficulty lie
• Info used to assist diagnosis & management

Question 23

Comparison Standard

Answer 23

• Normative comparison - compare results to normative sample
  = tests are ‘normed’ - given to many without cognitive impairment to obtain pop. norms
  = People in normative sample are grouped by age/gender
• Individual comparison = compare results to estimated lifelong ability level of person

Question 24

Post-acute inpatient rehab

Answer 24

• ABI Rehab in Ranui
• Facility providing interdisciplinary rehab
• Addresses needs of patients
• Psychoeducation/family groups/ gradual return to community

Question 25

Mod to severe TBI

Answer 25

• Full neuropsych Ax 6 months post moderate to severe TBI
• Report = answer referral Qs
  = make recommendations ihat aim to move client towards independence
  = summarise all relevant history

Question 26

Neuropsych Ax for mTBI

Answer 26

• Establish if con/mTBI did occur
• Review severity indicators
• Review presenting symptoms
• Complete cognitive screening assessment
• Gather personal history