Trauma of the CNS

Question 1

anatomy of skull to brain (list layers)

Answer 1

scalp
periosteum of outer table
 inner table (fused to outer table)
potential epidural space
dura mater
potential subdural space
arachnoid
subarachnoid space (contains blood vessels and CSF)
pia mater
brain

Question 2

general rules for trauma

Answer 2

1) extent of external lesion is not reliable indicator of deeper lesions
2) lethal lesions of skull/brain may be small or absent

Question 3

where can soft tissue injuries occur

Answer 3

may be external on face or scalp
or
maybe internal - subepithelial, galeal or periosteal

Question 4

what are the 5 kinds of fractures that occur in skull?

Answer 4

linear
compound
complex
depressed
contrecoup

Question 5

what is a linear fracture?

Answer 5

secondary to contact with large flat object - fracture begins along inner table–> usually not lethal

Question 6

what is a compound fracture?

Answer 6

fx associated with scalp laceration

Question 7

what is complex fracture?

Answer 7

fx involving multiple bones

Question 8

what is depressed fracture?

Answer 8

secondary to contact with small objects

Question 9

what is contrecoup fracture>?</p>

Answer 9

located distant from point of injury

Question 10

what typically causes a hinge fracture?</p>

Answer 10

auto accident - it is gaping fracture extending across entire base

Question 11

> what are the two types of dural hematomas? How are they different?</p>

Answer 11

epidural - b/w skull and dura & arterial bleeding

subdural - below dura & venous bleeding

Question 12

how does brain change in response to epidural hematoma?

Answer 12

compression! Caused by epidural blood - accurate rapid dx for immediate evacuation is mandatory to ensure survival

Question 13

which is more serious epidural or subdural hematoma?

Answer 13

epidural

Question 14

describe the pathogenesis of SDH

Answer 14

caused by motion of brain with respect to skull and dura tearing bridging veins
typically located over cerebral convexities
increased risk in people w/ brain atrophy
tears of veins more likely with rapid acceleration/deceleration

Question 15

what is the most common traumatic lesion of brain?

Answer 15

contusion/laceration

often associated with brain swelling

Question 16

what are the types of contusions/lacerations? (3)

Answer 16

1) fracture C/l - at site of fracture and tend to be severe
2) coup contusion - caused by bending/rebounding of skull at site of injury w/ or w/o fracture
- moving object striks stationary but movable head
3) contre coup contusion - located distant, usually opposite point of impact

Question 17

what are the two mechanism of contre coup contusions?

Answer 17

1) impact - moving head strikes fixed object

2) impulsive loading- head set in motion or moving head is stopped without being struck or impacted

Question 18

where are contre coup contusions most common?</p>

Answer 18

orbito-frontal surfaces & temporal bones - where brain contacts skull

Question 19

do contusions cause seizures?

Answer 19

yes

Question 20

what typically causes closed head injuries?

Answer 20

severe angular acceleration forces

most common in pedestrian-bike-vehicular impracts, helmeted cyclists, shaken babies

Question 21

what are 3 types of diffuse brain injury?

Answer 21

diffuse axonal
concussion
brain swelling

Question 22

what is typical distribution of lesions secondary to angular acceleration?

Answer 22

parasagittal white matter
corpus collosum
septum pellicudum/fornix
deep grey
superior cereballar peduncle

Question 23

what are retraction balls?

Answer 23

hallmark of diffuse axonal injury - swelling in axons due to build up of transport materials b/c cytoskeleton is damaged

Question 24

describe pathophys effects of severe concussion

Answer 24

hallmark of diffuse axonal injury - swelling in axons due to build up of transport materials b/c cytoskeleton is damaged
elevated ca2+ –> neuronal cell death
elevated lactic acid

Question 25

what can cause ischemic brain damage?

Answer 25

concussion (causes swelling)
hypotension-cardiac arrest
status epilepticus

Question 26

what occurs after transection of brainstem secondary to hyperextension?

Answer 26

death instantaneously

Question 27

basic stats about abusive CNS trauma in infants/children

Answer 27

65% of abused I/C die of CNS trauma

Question 28

how common is SDH in shaken infants?

Answer 28

80 - 90% of infants who are shaken have SDH –> usually not deadly

Question 29

what are common injuries of shaken babies?

Answer 29

SDH
transection of corpus collosum
gliding contusion
transection of spinal cord
optic nerve sheath hemorrhages
black brain