Trauma of the CNS Flashcards
I am not certain what to take from this lecture...
anatomy of skull to brain (list layers)
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
general rules for trauma
1) extent of external lesion is not reliable indicator of deeper lesions
2) lethal lesions of skull/brain may be small or absent
where can soft tissue injuries occur
may be external on face or scalp
or
maybe internal - subepithelial, galeal or periosteal
what are the 5 kinds of fractures that occur in skull?
linear compound complex depressed contrecoup
what is a linear fracture?
secondary to contact with large flat object - fracture begins along inner table–> usually not lethal
what is a compound fracture?
fx associated with scalp laceration
what is complex fracture?
fx involving multiple bones
what is depressed fracture?
secondary to contact with small objects
what is contrecoup fracture>?</p>
located distant from point of injury
what typically causes a hinge fracture?</p>
auto accident - it is gaping fracture extending across entire base
> what are the two types of dural hematomas? How are they different?</p>
epidural - b/w skull and dura & arterial bleeding
subdural - below dura & venous bleeding
how does brain change in response to epidural hematoma?
compression! Caused by epidural blood - accurate rapid dx for immediate evacuation is mandatory to ensure survival
which is more serious epidural or subdural hematoma?
epidural
describe the pathogenesis of SDH
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
what is the most common traumatic lesion of brain?
contusion/laceration
often associated with brain swelling
what are the types of contusions/lacerations? (3)
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
what are the two mechanism of contre coup contusions?
1) impact - moving head strikes fixed object
2) impulsive loading- head set in motion or moving head is stopped without being struck or impacted
where are contre coup contusions most common?</p>
orbito-frontal surfaces & temporal bones - where brain contacts skull
do contusions cause seizures?
yes
what typically causes closed head injuries?
severe angular acceleration forces
most common in pedestrian-bike-vehicular impracts, helmeted cyclists, shaken babies
what are 3 types of diffuse brain injury?
diffuse axonal
concussion
brain swelling
what is typical distribution of lesions secondary to angular acceleration?
parasagittal white matter corpus collosum septum pellicudum/fornix deep grey superior cereballar peduncle
what are retraction balls?
hallmark of diffuse axonal injury - swelling in axons due to build up of transport materials b/c cytoskeleton is damaged
describe pathophys effects of severe concussion
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
what can cause ischemic brain damage?
concussion (causes swelling)
hypotension-cardiac arrest
status epilepticus
what occurs after transection of brainstem secondary to hyperextension?
death instantaneously
basic stats about abusive CNS trauma in infants/children
65% of abused I/C die of CNS trauma
how common is SDH in shaken infants?
80 - 90% of infants who are shaken have SDH –> usually not deadly
what are common injuries of shaken babies?
SDH transection of corpus collosum gliding contusion transection of spinal cord optic nerve sheath hemorrhages black brain
