TBIs

Question 1

TBI def

Answer 1

alteration/malfunction of brain function from external force
TBI is a process, not an event!
Secondary injury can be more damaging than primary injury
i.e. hit head and occlude airway–>airway occlusion has most sev. effects

Question 2

main mechs of brain injury

Answer 2

Brain Contusion

Increased intracranial pressure ( ICP)

Diffuse Axonal Injury

Question 3

primary injury

Answer 3

Irreversible cellular injury as a direct result of the injury
Prevent the event (wear helmet)

Question 4

secondary injury

Answer 4

Damage to cells that are not initially injured-“watershed”
Occurs hours to weeks after injury
Prevent hypoxia and ischemia (hypotension)

Question 5

brain contusion

Answer 5

cell death accompanied by hemorrhage (leakage of blood)

The soft brain tissue is vulnerable to contusion in head trauma

The contusion often occurs at a site distant from the point of impact
(coup and counter-coup)

Question 6

volume of intracranial vault

Answer 6

80% brain tissue
10% blood
10% cerebrospinal fluid
*An increase in the volume of any of these  causes increased ICP*
ha, AMS, coma

Question 7

inc. IC pressure

Answer 7

The brain can swell (edema), but little room esp. in young adults (more room in infants, old ppl)

Excess blood can accumulate due to hemorrhage

Cerebrospinal fluid can accumulate due to blockage of outflow

Question 8

key ICP concepts

Answer 8

The intracranial vault is a fixed volume –> Bone does not expand!

There is only one way out of the intracranial vault –> the opening at the base of the skull known as the foramen magnum

When the brain is squeezed through the foramen magnum (herniation), the brainstem is compressed, the patient stops breathing, and the patient dies

Question 9

Diffuse Axonal Injury

Answer 9

Occurs in up to 1/2 of traumatic brain injuries1

Is a diffuse form of injury, meaning that damage occurs over a more widespread area than in focal brain injury

Involves the shearing of axons in the white matter tracts

Question 10

DAI manifests

Answer 10

Is one of the major causes of unconsciousness and persistent vegetative state after head trauma.

Over 90% of patients with severe DAI never regain consciousness (those that do wake up often remain significantly impaired)

Question 11

Head Injury-Normal Physiology

Answer 11

Brain consumes 20% of total O2 
Receives 15% of Cardiac Output
Brain tissue perfusion
CPP versus CBF
CPP=MAP-ICP
MAP=(SBP-DBP/3) + DBP

Autoregulation
(CPP) 50-150 mm Hg

Question 12

ICP measurements

Answer 12

Normal

Question 13

ICP physical findings of inc. ICP

Answer 13

Neurologic deterioration (know dermatomes)
Unilaterally dilated pupil
Hemiparesis
Posturing

Question 14

TBI pks in who

Answer 14

Peak male 15-24 years MVA, assault
Peak male > 65 years falls
falls>unknown>MVA>struck>assault

Question 15

TBI key hx

Answer 15

Mechanism of Injury
Patient’s condition prior to incident
Co-morbid factors
Patient’s immediate post trauma condition
Patient’s current condition

Question 16

other injuries w. TBI

Answer 16

consider mech. of injury
Always consider a spinal cord or vertebral column injury in a patient with a traumatic brain injury
(Esp in those pts that are unconscious!!) -C-scan spines, don’t want to miss
Remember: SCIWORA! (SCI w.out radiological abnormality)

Question 17

TBI primary survey

Answer 17

Airway (while maintaining cervical spine stabilization)
Breathing
Circulation (checks all)
Disability (Neurologic assessment) AVPU—alert ;responds to verbal stimuli; responds to painful stimuli; unresponsive
Exposure

ATLS? prim. survey

Question 18

prevent secondary brain injury from

Answer 18

Hypoxemia
Hypotension
Anemia
hyperglycemia
evacuation of mass

Question 19

Airway control with cervical spine immobilization, If a definitive airway is needed..
goal??

Answer 19

Orotracheal Rapid Sequence Intubation

Goal of RSI is to blunt rise in ICP and maintain adequate MAP

Question 20

decerebrate

Answer 20

extended

Question 21

decorticate

Answer 21

flexed

Question 22

Acute Neurological Examination in severe TBI

Answer 22

Pupil assessment
Motor gross function (posturing)
Secondary Survey

Question 23

Glasgow Coma Scale

Answer 23

Best Eye Response. (4)
1 No eye opening.
2 Eye opening to pain.
3 Eye opening to verbal command.
4 spontaneously

Best Verbal Response. (5)
1 No verbal response
2 Incomprehensible sounds.
3 Inappropriate words.
4 Confused
5 Orientated

Best Motor Response. (6)
1 No motor response.
2 Extension to pain.
3 Flexion to pain.
4 Withdrawal from pain.
5 Localising pain.
6 Obeys Commands.

Question 24

concussion

Answer 24

Any alteration of Cerebral Function Caused by a Force to the Head with any or one:

Brief LOC
Headache
Visual changes
Personality change
Fatigue
Balance disturbances
Light headed
Concentration disruptions
Amnesia

Question 25

scalp lacerations

Answer 25

May lead to massive blood loss (even w. small cut)

Small galeal lacerations may be left alone

Question 26

skull fx

Answer 26

Linear and simple comminuted skull fractures
Exploration of wound
Ppx antibiotics are controversial
Occipital fxs have a high incidence of other injury
If depressed beyond outer table-requires NS repair?

Question 27

assessment for concussion

Answer 27

SCAT3

Question 28

basilar fracture

Answer 28

Most common-petrous portion of temporal bone, the EAC and TM

get small slice imaging, typ. CT may miss

Question 29

Basilar skull fx w. dural tear signs

Answer 29

CSF otorrhea
CSF rhinorrhea
Battle Sign
Raccoon Sign
hemotympanum (may be occluded)
vertigo
hearing loss
7th nerve palsy (facial, Bell's)

Question 30

CSF testing (basilar fx)

Answer 30

Ring sign, glucose or CSF transferrin

Question 31

(basilar) skull fx injuries should be started on…

Answer 31

ppx abx

Ceftriaxone 1-2 gm

Question 32

specific head injuries

Answer 32

Epidural Hematoma

Subdural Hematoma

Subarachnoid Hemorrhage

Intraparenchymal Hematoma

ddx based on presentation, cause, imaging

Question 33

epidural hematoma

Answer 33

Rupture of Middle Meningeal Artery

Associated with fracture of Temporal bone (or just blunt injury)

Question 34

epidural hematoma asso. w. fx of temporal bone

Answer 34

Rapid expansion under systemic arterial pressure
“Lucid” interval (fine for a bit)

Transtentorial herniation
CN III Palsy-down and out
CT shows Biconvex disk-bulges out like lens

Question 35

Subdural Hematoma

Answer 35

Rupture of Bridging Veins
Slow dev. due to low pressure venous system (days-wks)

Seen in elderly, alcoholics, blunt head trauma, shaken baby

Question 36

Subdural Hematoma CT

Answer 36

Crescent-shaped hemorrhage-goes along lines of cranium

Crosses suture lines; Midline shift–>herniation

Question 37

Subarachnoid Hemorrhage

Answer 37

Rupture of an aneurysm
Usually a Berry aneurysm or AVM

ocular nerve palsy-down and out (like epidural?)

Question 38

subarachnoid hemorrhage can be traumatic or atraumatic

time course?

Answer 38

Atraumatic -> Hypertension, aneurysm

Traumatic -> Usually blunt head trauma

*Rapid time course
“Worst headache of life”
“thunderclap”

Question 39

Subarachnoid Hemorrhage CT

Answer 39

subarachnoid blood
Many times bilateral or Circle of Willis
If CT negative then recommend lumbar puncture (atraumatic)

Question 40

Intraparenchymal Hematoma

occurs where?

cause?

Answer 40

Basal ganglia and internal capsule
In trauma, can be lobar

Systemic hypertension
Also due to vasculitis, neoplasm and trauma

Question 41

IP hemorrhage doesn’t usually ???

Answer 41

rapidly expand or cause significant edema or midline shift

Unless patient is on an anticoagulant

Question 42

IP hem dx

px?

Answer 42

CT scan of brain

usually good
Depending upon cause (good in trauma)
Supportive care while it resolves

Question 43

specific head injuries: diffuse axonal injury

Answer 43

Disruption of axons in white matter and brainstem

Injury occurs immediately and is irreversible

Seen after MVC or shaken baby syndrome

Usually have persistent vegetative state

CT usually normal
MRI with multiple, diffuse abnormalities