Lecture 7: Pathology of Head Spinal Trauma Flashcards
What is caput succedaneum?
An edematous swelling formed under the presenting part of the scalp of a newborn infant as a result of trauma sustained during delivery
What is galea aponeuortica?
A muscle that covers the upper part of the cranium
-attached to the frontal and occipital bellies and allows scalp to move freely over underlying bone
What is the cephalhematoma?
A hemorrhage between the skull and the periosteum of newborn baby
Boundaries are limited to individual bone because periosteum is like the covering of a specific bone
What is the periosteum?
A membrane that lines the outer surface of all bones
What are the general rules of head trauma?
- Extent of external lesion is not a reliable indicator of deeper lesions
- Lethal lesion(s) of skull/brain may be small or absent
What is soft tissue?
The tissues that connect, support, or surround other structures and organs of the body
NOT being bone
Includes: tendons, ligaments, fascia, skin, fibrous tissues, fat, synovial membranes, muscles, nerves and blood vessels
What are the different types of fractures?
- Linear
- Compound
- Complex
- Depressed
- Contrecoup
What is a linear fracture?
SECONDARY to contact with large flat object
-fracture begins along inner table
(Outer and inner table refer to layers of cranium that are separated by diploe)
Not associated with abnormality
What is a compound fracture?
A fracture associated with a scalp LACERATION
What is a complex fracture?
Fracture involving MULTIPLE bones
What is a depressed fracture?
Appears as a fragment of skull being depressed
Secondary to contact with small objects
Example: bullet
What is a contrecoup fracture?
A fracture located distant from point of injury
What is difference between coup and contre coup contusion?
Coup is the contusion occurs at the site of impact
Contre coup is the contusion occurs at a point opposite from point of impact
What are basal skull fractures and hinge fractures associated with?
Motor vehicular accidents
What’s a hinge fracture?
A severe form of basal skull fracture in which you can open occipital bone (lateral to foramen magnum) like a book
Individual dies from this
What are the key characteristics of epidural hemorrhages?
Serious, individual dies ARTERIAL bleeding Lucid interval (minutes to hours) Middle meningeal artery Compresses brain from the lateral side
What are the key characteristics of subdural hemorrhages?
VENOUS bleeding
Much more common
Blue gray color underneath dura
What is significant about the “currant jelly” clot that may be seen?
indicative of large acute subdural hematoma
What happens if patient survives subdural hematoma and it is not evacuated?
Newly formed vessels will create a SUBDURAL MEMBRANE
-these newly formed vessels may re-bleed
Golden color is due to hemosiderin
What is the pathogenesis of subdural hematoma?
- Caused by motion of brain with respect to skull and dura tearing BRIDGING veins
- Typically located over cerebral convexities
- Increased risk in people with brain atrophy
- Tears of veins more likely with rapid ACCELERATION/deceleration
What are bridging veins?
Veins that drain the underlying neural tissue and puncture the dura mater
Empty into dural sinuses
-is torn because brain moves while dura is rigid…
What are the most common traumatic lesion of brain? Located?
Contusions and Lacerations
Located at gyral crests and associated with brain swelling
What are the types of Contusions/Laceratiosn (C/L)
- Fracture C/L: at site of fracture and tend to be severe
- Coup contusions
- caused by bending/rebound of skull at site of injury with or w/o fracture
- moving object strikes stationary but movable head (baseball bat)
- Contrecoup contusions
- located distant usually opposite from point of impact
What are the 2 mechanisms of contre coup contusion?
- Impact: Moving head strikes fixed object (e.g. occiput strikes ground)
- Impulsive Loading: head set in motion or moving head is stopped without being struck or impacted (blow to the face)
Where are the contre coupe C/L most common?
- orbito-frontal surfaces
2. temporal poles
What is common from old contusions/lacerations?
Patients who recover have post-traumatic SEIZURES
Gold-brown from deposition of hemosiderin (iron deposit)
What are the 3 principle types of diffuse brain injury?
- diffuse axonal injury
- concussion
- brain swelling
What is mechanoporation?
When concussion damages endothelium layers and allows fluid to over run brain and cause brain swellings
What is closed head injury?
Result from severe ANGULAR acceleration forces
Scalp/skull injury may or may not be present
Most common: pedestrian-bicycle/vehicular impacts (when pedestrian is wearing helmet)
Found classically in PARAMEDIAN of a brain
Could be transection of corpus callosum
Where do you commonly get lesion of brain stem from closed head injury?
Rostral pons at the level of the locus ceoruleus
What are retraction balls?
Structures present in brainstem if individual survives for longer than 12 hours
Amyloid precursor proteins (pooled material in axons)
Basically the bulbs that Dr. Smith talked about in mTBI
What are the pathophysiological effects of severe concussion?
- Elevated concentration of glutamate excitatory amino acid
- Activation of ATP dependent Na/K pump
- Elevated intracellular Ca neuronal cell death
- Elevated lactic acid
Trauma associated with ischemic brain damage could be secondary to:
- Concussion
- Hypotension-cardiac arrest
- Status epilepticus
When do you see transection of brainstem secondary to hyperextension?
When cyclist hits vehicle
Need to get a SAGITTAL slice to see it
How often do abused children die due to head trauma?
65%
How can you tell if there is abusive trauma in infants/children?
By looking for characteristic damage in brain/spinal cord/optic nerve
May or may not be external evidence of trauma
May or may not have fractures of skull/long bones
Can you kill baby by shaking him or her?
Yes…that’s how you get CNS trauma
When baby won’t stop crying…
e.g. spinal cord can be transected without any evidence of trauma
What happens when you see SDH in infants?
It means baby has been shaken
Does not require surgery
What contusions/lacerations are characteristic of babies being shaken?
Hemorrhagic contusions/lacerations of olfactory bulbs/tracts
What are gliding contusions?
Brain injury caused by displacement of gray matter of the cerebral cortex during angular acceleration of head.
- damage occurs at junction between gray and white matter - associated with SDH and DAI - tissue splits in frontal gyrus
What are key delineating features of shaken infants?
- transection of corpus callosum
- spinal cord, root, ganglia trauma (70%)
- Damaged axons
- SDH (80-90%)
- Gliding contusions
- Hemorrhages of optic nerve sheath (85%)
- C/Ls of olfactory bulb
What is the “black brain”?
Demonstrates the presence of TOTAL brain necrosis 2ndary to shock/concussion
Hallmark of abused infant
