Head injury

Question 1

which patients under NICE guidance require immediate CT head following a head injury?

Answer 1

GCS less than 13 on initial assessment
GCS less than 15 at 2 hrs post injury
suspected open or depressed skull fracture
evidence of basal skull fracture-haemotympanum, panda eyes, battle’s sign (mastoid ecchymosis), CSF leakage from nose or ears
more than 1 episode of vomiting
focal neurological deficit
post-traumatic seizure

Question 2

NICE indications for CT head within 8 hrs of head injury?

Answer 2

pt on warfarin with no other indications for CT head
adults with any of following RFs and who’ve experienced some loss of consciousness or amnesia since injury:
age 65 or older
hx of bleeding or clotting disorders
dangerous mechanism of injury e.g. fall from more than 1 metre/5 stairs
more than 30 mins retrograde amnesia of events immediately before the head injury.

Question 3

how might the blood Na+ concentration be affected in a patient following a head injury?

Answer 3

hypernatraemia may result from cranial diabetes insipidus-ADH not being produced by posterior pituitary so H2O not being reabsorbed by the CD of the kidneys.
OR
hyponatraemia as result of SIADH-other neuro causes include meningoencephalitis, stroke, SA or SD haemorrhage, GB syndrome. May also result from malignancy e.g. small cell lung, lymphoma, chest-pneumonia, drugs-opiates, SSRIs.

Question 4

causes of secondary brain injury following head injury? (subsequent insults to an already damaged brain from initial impact)

Answer 4

systemic: hypoxaemia, hypotension, hypocarbia, severe hypocapnia, pyrexia, hyponatraemia, anaemia, DIC.
intracranial: haematoma, brain swelling/oedema, raised ICP, cerebral vasospasm, epilepsy, intracranial infection.

Question 5

what is it particularly important to pay attention to with regards to drug hx of pt presenting with head injury?

Answer 5

anticoagulants

Question 6

layers of the SCALP?

Answer 6

skin
CT-highly vascular
aponeurosis-galea aponeurotica-dense CT
loose CT
periosteum

Question 7

what causes a ‘egg on the head’ appearance following head injury, and should we be worried?

Answer 7

this is due to a haematoma forming in the potential space between the galea aponeurosis and the perisoteum of the skull (subgaleal space), result of ruptured b.vessel
the lump on the head should go down with pressure BUT if wound over the lump then concern as infection risk-?subgaleal abscess, so ensure look for any puncture wound.

Question 8

if a pt experiences a facial injury, why is head injury a concern?

Answer 8

due to pressure trajectory to the skull

Question 9

normal ICP?

Answer 9

10mmHg

Question 10

why are children better able to cope with head injuries than adults?

Answer 10

they have flexible sutures that allow stretching so that ICP doesn’t increase as much.

Question 11

role of Cushing’s reflex?

Answer 11

to maintain adequate cerebral perfusion pressure:
if ICP increases, then want to increase MAP to ensure brain can continue to be perfused, so TPR increases with peripheral vasconstriction, but in response to this-baroreceptors triggered in aortic arch and carotid sinus-HR decreases.

Question 12

what pressure is required to perfuse the brain?

Answer 12

need at least 40mmHg difference between mean arterial pressure and ICP

Question 13

signs of a basal skull fracture?

Answer 13

raccoon eyes-periorbital ecchymosis-bruising around the eyes but no oedema
panda eyes-periorbital haematoma-oedema
CSF rhinorrhoea/otorrhoea
haemotympanum
mastoid ecchymosis-battle's sign
nerve palsies

Question 14

define concussion

Answer 14

LOC with no structural damage to the brain

Question 15

what is meant by diffuse axonal injury?

Answer 15

microhaemorrhages
pt complains of persisting pain
need rpt CT

Question 16

what are the important questions with regards to presenting complain in a pt who presents with a head injury?

Answer 16

MECHANISM of injury-part of head hit and on what, was head moving or object moving, speed of impact
pattern of subsequent behaviour-timeline of what happened before and after the injury
time from injury to presentation
further presenting complaints-other injuries, vomiting, seziures-even if pt is epileptic these are significant, headache, confusion, hearing and visual problems, diplopia
do they remember what happened? what is the last thing they remember-if amnesia more than 30mins before the injury then need CT
what is their baseline function? may be important in GCS calculation e.g. dementia or chronic neuro pt may have GCS less than 15 when well.

Question 17

indications in head injury for neurosurgery r/f?

Answer 17

depressed skull fracture
basal skull fracture
confirmed intracranial abnormalities on CT including cerebral oedema
CSF leakage
penetrating skull injury
skull fracture with any depression of consciousness, rpt fits, severe headache, focal neurology, persistent vomiting
GCS less than 13 after resuscitation
unexplained confusion for more than 4h
GCS deterioration
progressive focal neurological signs

Question 18

what does diffuse axonal injury tend to result from?

Answer 18

sudden acceleration/deceleration which causes shearing injury to the brain and diffuse axonal injury
assoc. with LOC but may be lack of external evidence of head injury
DAI commoner with loner decerlation time seen in pts restrained in RTAs

Question 19

when is C spine injury more likely to be assoc. with brain injury?

Answer 19

if mobile head hits a fixed object (deceleration/acceleration)

Question 20

indications for immediate plain radiograph imaging of C spine in head injury?

Answer 20

cannot actively rotate neck to 45 degrees (L and R)
not safe to move neck
focal neurological signs including paraesthesia in extremities
neck pain or midline tenderness with dangerous mechanism of injury or age over 65yrs
definitive diagnosis required urgently e.g. before surgery

Question 21

indications for immediate C spine CT in px of head injury?

Answer 21

GCS less than 13 on initial assessment
has been intubated
plain films technically inadequate, suspicious or defo abnormal
continued clinical suspicion despite normal plain films
pt being scanned for multi-region trauma

Question 22

give 5 reasons for intubating and ventilating patients with head injuries?

Answer 22

clear, maintain and protect the airway
maintain adequate gas exchange-prevent secondary brain injury
reduce ICP-will rise with hypoxia causing subsequent lactic acidosis and reflex vasodilatation, and PaCO2-rise also causes vasodilatation
facilitate CT
allow safe pt transport

Question 23

location of skull fracture implicated by battle’s sign (mastoid bruising)?

Answer 23

middle cranial fossa

Question 24

important symptoms to enquire about pt experiencing following a head injury?

Answer 24

LOC
amnesia (?more than 30mins before injury)
headache
vomiting
neck pain
seizures

ask about visual or speech disturbance, limb weakness, limb paraesthesia-examine for these along with abnormal tendon reflexes and problems with balance or walking to assess for focal neurological defecit. examine for any neck tenderness.

Question 25

factors that raise suspicion of NAI as cause of head injury in a child?

Answer 25

child not yet independently mobile
bruise/injury on non-bony part of face, or bilateral
bruises in multiple sites of similar sizes and disproportionate to mechanism of injury suggested
may be differing stories between parents, or inconsistent over time, or implausible with child’s injury, age
retinal haemorrhages or eye injury
delay in px

Question 26

examples of non-specific post concussion symptoms and if persistent, how they should be managed?

Answer 26

mild intermittent headache
nausea
dizziness
impaired memory or cognitive function
tinnitus
generalised wkness
irritability
fatigue
sleep disturbance

a/v normally resolve within 3 mnths
manage symptoms appropriately
analgesia as required
slow reintroduction to normal activities, regular schedule of activity and sleep
manage symptoms of anxiety, low mood
alcohol or drug misuse help as required

Question 27

advice for patients following a head injury who are at low risk of intracranial complications or C spine injury?

Answer 27

responsible adult should stay with the pt for 24hrs following the injury: they should be advised to look out for the following: difficulty rousing the pt, pt confusion, pt vomiting, seizure, weakness, fluid from nose or ears, complaining of severe headache, then contact ED.
give verbal and written info and self care advice-reassure about common sympts pt might experience e.g. mild headache, dizziness, poor concentration, irritability, and to speak to GP if these persist for more than 2 wks, take plenty of rest, avoid contact sports for at least 3 wks, don’t take alcohol or sleeping tablets.