Traumatic Brain Injury

Question 1

TBI FACTS

Answer 1

• approx 1 every 20 seconds in US
• 22% overall mortality

Question 2

What are the 2 types of TBI

Answer 2

• Force-Inflicted Wound
• Encephalophathy

Question 3

2 Types of force-inflicted wounds

Answer 3

• Closed head
• Open head

Question 4

Types of closed head wounds

Answer 4

1. Concussion
2. Blunt Force
3. Epidural
4. Deceleration
5. Rotational
6. Diffuse Axonal

Question 5

Concussion

Answer 5

• .6-1% annual prevalence
• 1/100 people per year

1. Brain bounces inside crainium, potentially causing hematoma and swelling
2. Brain stretches from base, cause tissue to rub together and axons to become distended
3. Brain preesses down or stretches the brainstem, cause it to temporarily shut down

Question 6

Symptoms of concussion

Answer 6

• headache
• nausea
• sleepiness
• ocassional vomiting
• loss of orientation
• loss of conciousness for less than 30 mins
• amnesia for less than 24 hours
• normal pupillary response

Question 7

Treatment of Concussion

Answer 7

• no treatment unless there are focal injuries seen on CT scan
• ice on contustions
• monitor vital signs for 24 hours
• prognosis is excellent

Question 8

Blunt Force Wound

Answer 8

• a smack to the skull on the sides
• can cause epidural or subdural hematoma (outer layer of meniges)
• venous bleed, not artieries or capillaries
• likely to bleed into brain
• crescent shape on CT scan
• 40-60% mortality

Question 9

Epidural

Answer 9

• blood collects between skull and dura mater
• appears as convex blood collection on CT scan
• problems with pressure in the brain
• 10% mortality

Question 10

Deceleration Injury

Answer 10

• head is moving in one direction and is very quickly stopped or sent in the other direction
  
  • car accidents
  • falls
• brain bounces from one side to the opposite side which is called coup-contrecoup injury.

Question 11

Rotational Injury

Answer 11

• when head is twisted by impact, parts of the brain/skull can rub against each other, instead of direct impact
• beause brain is split into two hemispheres, its easy for it to rub against itself

Question 12

In a rotational injury, what happens if the brain rubs against the meniges/skull?

Answer 12

• veins in arachnoid mater can rupture
• causing subdural/subarachnoid hemorrhage

Question 13

In a rotational injury, what happens if the brain rubs against itself?

Answer 13

• axon get stretched and torn, and petechial/intreparenchymal hemorrhage can result
• this is known as SHEARING injury
• which causes Diffuse Axonal Injury..

Question 14

Diffuse Axonal Injury

Answer 14

• neurons get stretched by deceleration or abraded by shearing
• diffuse because shearing injuries can occur everywhere
• hard to see in brain scans cause they are microscoptic and all over the place
• poor prognosis
• predicts coma
• the more evident on the brain scan, the higher mortality rate

Question 15

In a DAI, why can deterioration occur weeks after injury?

Answer 15

• broken axons release apoptotic factors that cause surrounding tissue to kill itself

Question 16

Open Head Wounds

Answer 16

1. Penetrating
2. Crushing

Question 17

Penetrating

Answer 17

• cranium is penetrated either by the skull being hit really hard by a blunt object or by a piercing object such as a bullet
• if gunshot victim survives, prognosis for recovery is very good because the gunshot is in and out.
  
  • the focal area of the brain add to survival

Question 18

Crushing

Answer 18

• skull is crushed between two objects cause widespread fracture and brain visibility
• much higher risk of infection than closed head wounds
• air can enter brain cavity and disrupt skull pressure (pneumocephalus)

Question 19

Herniation

Answer 19

• pressure pushes the brain where its not supposed to go
• caused in extra-axial bleeds because ICP increases, brain swells, and blood in meniges pushes the brain in places it should not go

Question 20

Types of Herniation

Answer 20

1. Supratentorial
2. Infratentorial

Question 21

Supratentorial

Answer 21

• when the brain herniates above tentorium
• subfalcine
  
  • cingulate gyrus pushed under falx cerebri- MOST COMMON
• central
  
  • parts of midbrain pushed down tentorium)
• transcalvarial
  
  • brain pushed outside of cranium)
• uncal
  
  • medial temporal lobe pushed through tentorium

Question 22

Infratentorial

Answer 22

• herniation below tentorium
• upward cerebellar
  
  • cerebellum pushed up through tentorium
• downward cerebellar (tonsillar)
  
  • cerebellum pushed through foramen magnum

Question 23

Symptoms of TBI

Answer 23

• if concious: Ps start out lucid and complain of worsening headache
• slip into unconciousness/coma
• confusion
• nausea/vomiting
• loss of balance
• altered mental status
• loss of orientation
• altered pupillary response

Question 24

Fencing Posture

Answer 24

• arm flies straight out as a tonic response to disruption of neurochemistry
• seen often in contusion heading to unconciousness

Question 25

Opisthotonus

Answer 25

* severe muscle spasms cause by compression of corticoreticular tracts in midbrain * back and head arch back * not super common in TBI

Question 26

Decorticate Posture

Answer 26

* arms fold into prayer position * legs extended * feet turned inwards * mucles rigid * indicative of pressure or damage to brainstem * BAD * can also be seen in coma Ps

Question 27

Decerebrate Position

Answer 27

* arms straighten * hands curl downward and outward * legs extend, feet turn inwards * teeth clenched * very rigid * if unconcious and continuous, indiates brainstem herniation * VERY BAD