Head trauma

Question 1

TBI primary

Answer 1

immediate structural damage

• lacerations
• hematomas
• contusions
• tissue avulsions
• coup/contracoup injury (injury on another area of brain due to initial impact)
• shear diffuse- axonal injury

Question 2

TBI secondary

Answer 2

neurotoxic cascade (not same as secondary insult)
- intracellular and extracellular derangement

Question 3

Cerebral concussion definition

Answer 3

does NOT require a LOC
associated with transient neurological changes such as:
transient amnesia
confusion
disorientation
visual changes without any gross cerebellar abnormalities or deficits on exam and a trauma

Question 4

Cerebral blood flow

Answer 4

head trauma can alter CBF by creating an expanding mass or cellular death

need minimum blood flow to avoid worsening injury and provide nutrients

Question 5

CBF amount

Answer 5

750 cc/min

Question 6

MAP means

CPP means

Answer 6

mean arterial pressure

cerebral perfusion pressure

Question 7

TBI classification- GCS scale

Answer 7

CNS injury is the number one cause of traumatic death

Mild- 13-15, brief LOC
Mod- 9-12, mild confusion or focal deficit
Severe- <9, survivors have life long disability

Eye
1- no eye 
2- eye opening to pain 
3- eye opening to speech 
4- eye opening spontaneously 

Verbal 
1- non 
2- incomprehensive sounds 
3- inappropriate words 
4- confused 
5- oriented 

Motor
1- none
2- extension to pain 
3- flexion to pain 
4- withdraws from pain 
5- localizes to pain 
6- obeys commands 

less than 8= intubate

Question 8

Cushing’s reflex

Answer 8

hypertension (increased systolic BP)
bradycardia (decreased pulse)
decreased RR

systemic response to increased ICP

Question 9

Herniations

Answer 9

Medial- temporal lobe (Uncal)= most common
Central
Cingulate
Posterior fossa

Question 10

Canadian rule

Answer 10

tries to find those who need a CT, doesn’t say you need to get a CT, it says you do not need a CT

Inclusion criteria: 
GCS- 13-15 
Age >16yrs 
No coagulopathy or on anti-coagulation 
No obvious open skull fracture 

Exclusion- Head CT not required if ALL are absent
(long list)

Likelihood of missing an injury is small

Tries to find those on blood thinners (anti-coagulants), over 60, open fractures

Question 11

Epidural bleed- epidural hematoma

Answer 11

lenticular- acute collection of blood above the dura (do not extend beyond sutures), usually from middle meningeal artery

LOC–> Lucidity–> rapid decompensation with signs of increased ICP with pupillary dilation and unconsciousness

Question 12

Subdural bleed

Answer 12

crescent shaped- collection of venous blood between the dura and arachnoid- in subdural space

a result of venous bleed (bridging veins)

Slower onset than epidural but higher incidence of underlying brain injury

Acute= <14 d old, >14= chronic

Question 13

Diffuse axonal sheer injury

Answer 13

result of abrupt deceleration forces
axons tear along the white/grey matter interface
CT can appear normal or small petechial hemorrhages
MRI- best assessment

Question 14

Basilar skull fracture

Answer 14

base of skull typically petros portion of temporal bone
associated with CN 7,8 and cerebral vascular problems

raccoon eyes
hemotympanum (blood behind TM)
battle sign bruising behind ears and/or
drainage from nose or ear canal

need head and neck angio + CT

Question 15

Tx for uncal, central, cingulate, and posterior fossa herniation?

Answer 15

single dose of mannitol over 15 min (acts as a diuretic)

to decrease volume and ICP

Question 16

Pediatric head injury- PECARN >2

Answer 16

exclusion criteria

AMS 
severe mechanism 
clinical signs of baser skull fracture 
any loc 
hx of vomiting 
hx of severe headache 

if none of these then no CT indicated

Question 17

Who is at higher risk for intracranial injury after trauma? Why?

Answer 17

less than 2yo- large heads, weak torso and compressibility of skull (also for non-accidental trauma (NAT)

elderly particularly SDH- cerebral atrophy resulting in bridging vein tears with deceleration forces

alcoholics- greater incidence of trauma and cerebral atrophy and coagulation disorders (vit k dependent)- thiamine deficiency

pts on anticoagulants (or intrinsic bleeding disorders)

Question 18

Uncal herniation

Answer 18

medial portion of temporal hemispheres shifts below tentorium

ipsilateral 3rd nerve palsy
ptosis
Babinski reflex

eventually cerebral peduncle gets compressed and motor hemiplegia occurs

Question 19

Central herniation

Answer 19

both hemispheres through tentorium

pinpoint pupils
hemiparesis

Question 20

Cingulate herniation

Answer 20

cingulate gyrus is forced underneath the falx compression of ventricles and impairing cerebral blood flow

Question 21

Posterior fossa herniation

Answer 21

bleeding pushes cerebellar tonsils through foramen magnum of upward through tentorium

coma &
brain stem dysfunction occur rapidly causing death

pinpoint pupils that are fixed

Question 22

What is the goal of TBI tx

Answer 22

maintain cerebral perfusion pressure

avoid the 5 Hs

• hypotension
• hypoxia
• hypoglycemia
• hypercarbia
• hyperthermia

Question 23

What is important for conditions of increased ICP?

Answer 23

seizure prophylaxis

Question 24

What happens in MAP less than 50mmHg and more than 110mmHg?

Answer 24

lose the ability to auto regulate
cerebral perfusion pressure will drop
worsening injury occurs

Question 25

What are some tx to keep CPP above 50?

Answer 25

hyperventilation (35mmHg) to bring down CO2 & vasoconstriction helps being down ICP Fine line- vasoconstriction caused by increasing RR (respiratory alkalosis) causes ischemia which then increases cascade of cellular death ``` Give oxygen and if MAP is low: Fluid bolus (saline+ lactated ringer) & blood ```

Question 26

Pediatric head injury- PECARN <2

Answer 26

``` normal MS frontal scalp hematoma no palpable skull injury low risk mechanism acting normal by parents loc <5sec ``` no CT indicated ``` exclusion: GCS <15 palpable skull fx AMS dangerous mechanism ```