Traumatic Brain and Head Injury

Question 1

what is a traumatic brain injury?

Answer 1

non-degenerative, non-congenital insult to the brain from an external mechanical force, possibly leading to temporary or permanent impairment of cognitive, physical and psychosocial functions

Question 2

TBI is the commonest cause of death and disability in people age 1-40 in UK - true or false?

Answer 2

true

Question 3

what groups are high risk to TBI?

Answer 3

young men and elderly 
previous head injuries 
residents of inner cities 
alcohol and drug abuse 
low-income

Question 4

what are examples of mechanism of TBI?

Answer 4

assault
falls
RTC
sports

Question 5

what GCS score is mild?

Answer 5

14 or 15, brief LOC

Question 6

what GCS score is moderate?

Answer 6

9-13

Question 7

what GCS score is severe?

Answer 7

3-8

Question 8

NICE states that patients who have sustained head injury with any of what risk factors should have CT within one hour?

Answer 8

GCS <13 initially
GCS <15 at 2 hours
suspected open or depressed skull fracture 
any sign of basal skull fracture
post traumatic seizure 
focal neurological deficit
more than one vomiting episode
suspicion of NAI

Question 9

CT should also be immediately requested in patients with what risk factors if they experienced some LOC or amnesia since injury?

Answer 9

age 65 or more
coagulopathy
dangerous mechanism of injury

Question 10

what are the two different types of head injury?

Answer 10

focal (traumatic haematoma or contusion)

diffuse (DAI)

Question 11

what are the three types of traumatic haematoma?

Answer 11

extradural haematoma

subdural haematoma

intracerebral haematoma

Question 12

why would surgery take place in a traumatic head injury?

Answer 12

to control and monitor ICP/CPP (CPP = MAP - ICP)

prevent secondary insults

decompressive craniectomy = portion of skull is removed to give room for swelling brain

Question 13

how is raised ICP treated?

Answer 13

sedation: propofol, benzodiazepines, barbiturates

maximise venous drainage of brain

CO2 control

osmotic diuretics: mannitol, hypertonic saline

CSF release

Question 14

how can you maximise venous drainage of brain?

Answer 14

head of bed tilt

cervical collars, ET tube ties

Question 15

brainstem death must be diagnosed by who?

Answer 15

2 doctors, one of which is a consultant

Question 16

what are the symptoms of brainstem death?

Answer 16

no pupil response 
no corneal reflex
no gag reflex 
no vestibulo-ocular reflex 
no motor response 
no respiration

Question 17

can you recover from brainstem death?

Answer 17

no

Question 18

what are the symptoms of an extradural haematoma?

Answer 18

injury with LOC
lucid interval
rapid progression of neurological symptoms

Question 19

what neurological symptoms do you get in extradural haematoma?

Answer 19

deteriorating GCS
possible hemiparesis
unilateral fixed and dilated pupil
apnoea and death

Question 20

what is diffuse axonal injury (DAI)

Answer 20

brain injury which occurs in scattered lesions in white matter tracts and grey matter over a widespread area

Question 21

what causes diffuse axonal injury?

Answer 21

sheering forces

excitotoxicity and apoptosis

inflammatory mediator release

Question 22

how are sheering forces classified and where do they occur?

Answer 22

adams classification (1-4)

occur where density difference is greatest = grey / white interface

Question 23

how does excitotoxicity and apoptosis occur?

Answer 23

excitatory amino acids e.g. glutamate activated NMDA receptors resulting in Ca2+ mediated activation of proteases and lipases causing in further cell death

Question 24

what causes inflammatory mediator release?

Answer 24

cytokines

interleukins = IL6 levels higher in non survivors