Lec 68 Traumatic Brain Injury

Question 1

How do you diagnose traumatic brain injury?

Answer 1

• physical examination of orientation, level of consciousness, motor response, reaction of pupils to light, ability to talk, respiration

CT is gold standard

Question 2

What is the glasgow coma scale [GCS]?

Answer 2

assesses degree of consciousness on 15 point scale based on:

• eye opening response
• verbal response
• motor response

lower score on admission = worse outcome

Question 3

What are the different types of eye opening response as measured by the glasgow coma scale?

Answer 3

4 = spontaneous
3 = speech
2 = pain
1 = no response

Question 4

What are the different types of verbal response as measured by the glasgow coma scale?

Answer 4

5 = oriented to time place and person
4 = confused
3 = inappropriate words
2 = incomprehensible sounds
1 = no response

Question 5

What are the different types of motor response as measured by the glasgow coma scale?

Answer 5

6 = obeys commands
5 = moves to localized pain
4 = flexion withdrawal from pain
3 = abnormal flexion [decorticate]
2 = abnormal extension [decerebrate]
1 = no response

Question 6

What is a closed head injury vs penetratin?

Answer 6

closed = dura remains intact
penetrating = object pierces skull and breaches dura

Question 7

What is a skull fracture?

Answer 7

break in one or more of 8 bones of cranial portion of skull
usually due to blunt force trauma
likely associated with concussion

Question 8

What is etiology/signs of epidural hematoma?

Answer 8

blood between dura and skull
etiology: trauma leading to laceration of meningeal arteries
classic lucid interval before symptoms being; later –> blood increases ICP –> causes herniation, coma
have a convex lens shaped hematoma
pupil is localizing factor

Question 9

What are signs of subdural hematoma?

Answer 9

blood between dura and arachnoid
esp in older, alcoholic

acute: high ICP, life-threatening; better prognosis if chronic

may be acute, subacute [1-2 wks], or chronic {> 2 wks]

image = concave, crescent shaped hematoma widespread = limited by flax not sutures

Question 10

What is most at risk for subdural hematoma?

Answer 10

elderly, alcoholic

Question 11

What is etiology of subarachnoid hemorrhage?

Answer 11

aneurysm rupture, head trauma

Question 12

What is etiology of subdural hematoma?

Answer 12

etiology: trauma causing sheering of bridging veins that cross subdural space

Question 13

What are differences in epidemiology and outcome of epidural vs subdural hematoma?

Answer 13

subdural = more brain damage + more common + life threatening
epidural = less common + coma

Question 14

What are signs of subarachnoid hemorrhage [SAH]?

Answer 14

bleeding into subarachnoid space [between arachnoid and pia]

rapid onset “thunderclap” headache, N/V, confusion or lower consciousness, sometimes seizure, reactive vasospasm –> further hypoxic injury

Volume of SAH = most powerful predictor of 30 day mortality

Question 15

What is cerebral contusion? what parts of brain most at risk

Answer 15

cell death accompanied by leakage of blood = intraparenchymal injury

frontal and temporal lobes = most at risk because of ridges in skull base

can be hemorrhagic or not

Question 16

How does diffuse cerebral injury manifest?

Answer 16

concussion or diffuse axonal injury

Question 17

What is concussion? signs?

Answer 17

transient alteration of consciousness due to impact to head; due to temporary alteration of ion channels and energy balance

can have normal head CT

diagnosis is purely clinical

Question 18

What are acute clinical signs of concussion?

Answer 18

confusion, retrograde and anterograde amnesia, seeing stars or white/black out visually

Question 19

What are signs of post concussion syndrome?

Answer 19

days to months
headache, N/V, dizziness, visual complaints, fatigue depression, difficulty concentrating, reading, memory, sleep disturbance

Question 20

What is second impact syndrome?

Answer 20

rare syndome where reinjury occurs before resolution of previous concussion
diffuse cerebral dysregulation with massive cerebral edema and herniation occurs

almost always younger than 20

Question 21

What is diffuse axonal injury?

Answer 21

shearing of axons from neurons that occurs with head injury
longer period of unconsciousness, coma
normal CT or can have evidence punctate hemorrhages in grey/white junctions or with deep hemorrhages [corpus callosum or ventricle]

clinical exam may be much worse than radiographic appearance

Question 22

What is chronic traumatic encephalopathy [CTE]?

Answer 22

occurs due to repetitive brain injury/concussions;
mech = possible repetitive axonal stretching and deformation
especially in unresolved concussions

Question 23

What is gross pathology of chronic traumatic encephalopathy?

Answer 23

similar to alzheimers

• cortical + medial temporal lobe + mamillary body atrophy
• separation of septum pellucidum
• tau protein immunoreactivity [neurofibrillary tangles]
• SN, locus ceruleus pallor

Question 24

What are early clinical features of chronic traumatic encephalopathy? late?

Answer 24

short term memory impairment, cognitive dysfunction, depression/apathy, emotional instability, impulse control issue, suicide

late = dementia, parkinsonism

Question 25

What is genetic risk factor for chronic traumatic encephalopathy?

Answer 25

apolipoprotein e4 allele [ApoE4]

Question 26

What is goal of severe head injury management?

Answer 26

prevent secondary injury = usually ischemic injury; due to hypoperfusion, hypoxia, hypotension

in ER: maintain BP > 90, attend scalp laceration, maintain O2 saturation > 90

OR: evacuation of mass lesions

ICU: monitor ICP, normovolemia