Traumatic Brain Injury

Question 1

What are the main mechanisms of primary (i.e. immediate) traumatic brain injury?

Answer 1

• Coup and contre-coup
• Diffuse axonal injury
• Extra/subdural haematomas
• Intracerebral haemorrhage

Question 2

How is diffuse axonal injury clinically recognised? What are the critical factors relating to its severity?

Answer 2

• Causes initial LOC (clear sign), usually related to acceleration/deceleration high velocity impacts
• Critical factors - acceleration magnitude, duration, rate of onset, direction (worse laterally)

Question 3

What are the secondary mechanisms causing damage in traumatic brain injury (e.g. complications after the initial insult causing further damage)?

Answer 3

• Oedema (vasogenic - extracellular or cytotoxic - intracellular), increased ICP, hypoxia, infections (meningitis, encephalitis), hydrocephalus (blood clots), free radicals, neurotransmitters, seizures, vasospasm

Question 4

What are the features of post-traumatic amnesia?

Answer 4

• Features: no continuous memory for day-to-day events, cannot lay down new memories, poor orientation, short attention span, irritable, aggressive, poor sleep/wake cycles, easily fatigued

Question 5

What scale is used to test for post-traumatic amnesia? What scores clear someone of PTA?

Answer 5

• Westmead PTA scale
  
  • 7 orientation questions (+ 5 memory if successful at these)
• 12/12 for 3 consectutive days

Question 6

What non-pharmacological management could be undertaken in someone with post-traumatic amnesia?

Answer 6

• Low stimulation environment, single room, low bed, no other cognitive assessments
• Noxious stimuli - other injuries, medications, constipation
• Orientation cues and familiar items from home
• Involve family, limit multiple visitors
• Minimise location changes

Question 7

What are features of a mild traumatic brain injury? What is appropriate management?

Answer 7

• LOC OR loss of memory OR alteration in mental state OR focal neurological deficits
  
  • Presentation: headache, neck pain, dizziness, tinnitus, reduced hearing, altered smell and taste, poor sleep, inattention, fatigue, concentration or memory problems. Generally non-specific.
• Patient and family education, psychiatric support as required. Step-wise approach to returning to work/driving

Question 8

What are predictors of moderate-severe traumatic brain injury outcomes?

Answer 8

• GCS within 24 hours
  
  • 13-15 mild TBI, 9-12 moderate TBI, 3-8 severe TBI (coma)
• Length of coma
• Post-traumatic amnesia presence
  
  • 5min-1hour mild TBI, 1hour-1day moderate TBI, 1day-1week severe TBI
• Age (better prognosis for children and young adults)
• Rate of early recovery

Question 9

What are the most frequently observed medical complications of traumatic brain injury?

Answer 9

• Raised ICP
• Post-traumatic epilepsy
  
  • Especially in penetrating trauma, ICH and early seizures

Question 10

What are typical personality characteristics of a person with an orbito-frontal brain injury?

Answer 10

• Impulsivity, disinhibition, agitation, aggression, self-centred

Question 11

What are typical personality characteristics of a person with an medial-frontal brain injury?

Answer 11

• Reduced initiation, spontaneity and motivation. Inertia, indifference. Difficult to rehabilitate

Question 12

What are the typical personality characteristics of a person with dorso-lateral-frontal brain damage?

Answer 12

• Reduced planning, judgment, problem solving, insight, concrete thinking, perseveration