B7-055 CBCL Trauma/Subdural Flashcards
primary causes of TBI [5]
concussion
CNS axonal injury
cranial nerve injury
contusion
laceration
concussion is largely caused by
angular acceleration
how can angular acceleration cause loss of consciousness?
torque to the RAS
what part of the brain is selectively vulnerable to the shearing stresses that occur due to angular acceleration?
high brainstem (midbrain/diencephalon)
torque causes transient stretching of axons without transection
concussion
torque tears axons with slow recovery and permanent disability
diffuse axonal injury
any symptom after any head injury is a
concussion
but symptoms will start immediately after injury
recovery from concussion followed by recurrent headache, impaired concentration, other minor neurologic symptoms
may persist for months to years
post-concussion syndrome
a patient with diffuse axonal injury can have relatively minor scans and still never wake up. why?
the axons of the RAS have been sheared off
cranial nerve injuries are often associated with […] fractures
basilar skull
most common cranial nerve affected by head injury
CN 1
(VII and VIII often susceptible as well)
CN 7 is likely to be damaged due to […] fracture
transverse petrous
CN 8 is likely to be damaged due to […] fracture
petrous pyramid
CN 12 is likely to be damaged due to […] fracture
hypoglossal canal
most common extraocular nerve affect by head injury
CN 4
blunt trauma to specific portions of the brain
underlying brain tissue crushed
contusion
forepart of brain slams into the front, then goes back is called […] injury
coup-contrecoup
what areas of the brain are selectively vulnerable to contusion? [2]
near rough, bony prominences (petrous bone)
falx
contusions typically affect the anterior temporal, subfrontal, and corpus callosum causing what symptoms?
apathy
short term memory deficits
grossly visible tear in the brain due to blunt or penetrating trauma
laceration
secondary injuries (mostly due to bleeding/swelling of the brain) [5]
edema
herniation
CSF derangements
seizures
infection
what patient population is especially vulnerable to herniation due to edema?
children
edema in the brain occurs due to […] occurring in the first 24-72 hours
cytotoxic cascade
bleeding between the periosteum and dura mater
epidural
bleeding between the dura and the pia
subdural
blood within the CSF space
subarachnoid
caused by a tear in the meningeal artery, vein, or dural sinus
epidural hemorrhage
caused by tear of the bridging pial veins and arteries
subdural hemorrhage
the interval between onset of symptoms is longer in […] hemorrhage
subdural (takes hours to come on)
risk factors for chronic subdural hemorrhage [2]
coagulopathy
severe brain atrophy
develops immediately after the injury and evolves from contusion
clinically resembles hypertensive hemorrhage
intracerebral hemorrhage
is surgical evacuation helpful for intracerebral hemorrhage?
not usually
caused by shearing of the parenchymal vessels
intracerebral hemorrhage
risk factors for intracerebral hemorrhage [2]
coagulopathy
amyloid vasculopathy
treatment for traumatic subarachnoid hemorrhage
generally supportive
typically occurs in the basilar cisterns
traumatic subarachnoid hemorrhage
can onset with headache and meningismus
traumatic subarachnoid hemorrhage
unilateral dilated
non-reactive pupil
what type of herniation?
lateral
midsize bilateral
non-reactive pupils
what type of herniation?
central
flow of CSF disrupted by subarachnoid and intraventricular blood
hydrocephalus
if the CSF obstruction is outside of the brain it is called
communicating
if the CSF obstruction is within the brain it is called
non-communicating
tear of the dura and arachnoid can result in […] leakage
CSF
a CSF leak can result in [3]
CSF hypotension
increased risk of infection
tension pneumocephalus
long term use of anti-seizure medication [does/does not] prevent post traumatic seizure
does not
a [higher/lower] number on the glascow coma scale is better
higher
[…] is the lowest the GCS goes
3
lens shaped hematoma
epidural
equation for cerebral perfusion pressure
CCP= MAP -ICP
ways to decrease blood volume to lower ICP
evacuate hematomas
hyperventilation (lowers CPP, only used temporarily)
ways to decrease CSF volume to lower ICP
external ventricular drainage
(also allows for monitoring of ICP)
ways to decrease brain volume to lower ICP
mannitol
steroids
decrease fluids
(dehydrates the normal brain and can get rebound increase ICP- temporary)
surgical procedure to give the swollen brain more room
craniectomy
which imaging modality is best in an acute setting?
CT head
which imaging modality is used as a quick screening tool for hydrocephalus, herniation, or intracranial hemorrhage
CT head
which imaging modality is best in a subacute or non-traumatic setting?
MRI
which imaging modality is would be used for acute hemorrhage?
CT head
which imaging modality is would be used for fracture?
CT head
which imaging modality is would be used for diffuse axonal injury?
MRI head
which imaging modality is would be used for chronic injury?
MRI head
which imaging modality is would be used for late stage hematoma?
MRI head
most common site for contusions following head injury [2]
orbital frontal cortex
anterior temporal lobe
(due to rough surface of sphenoid bone)
CN most likely to be affected by TBI
CN 1
interventions to prevent herniation prior to surgery
burr holes
hyperventilation
IV mannitol
ventricular shunt
convex hyperdensity on CT scan
epidural hematoma
period of lucency followed by a relatively rapid progression of neurologic symptoms
epidural hematoma
concave hyperdensity on CT
subdural hematoma
hyperdense findings on CT within the sulci or cisterns
subarachnoid hematoma
maintaining the head of the bed at […] degrees can help reduce cerebral edema
30
reduces cerebral edema by lowering PaCO2
hyperventilation
(causes arterial vasoconstriction)
reduce the cerebral metabolic rate, therefore reducing CSF flow
barbituates
late central descending herniation is characterized by
bilateral mid-range unreactive pupils
lateral (uncal) herniation is characterized by
unilateral dilated pupil
[…] herniation compresses the medulla and leads to respiratory arrest
tonsillar
[…] herniation can cause anterior cerebral artery infarct
subfalcine
what area of the brain is most likely to suffer from contusion following head trauma? [2]
anterior temporal pole
inferior frontal lobe
cause white matter tract injury in a widespread area
diffuse axonal injury
areas of the brain most affected by diffuse axonal injury [3]
brain stem
corpus callosum
cerebral hemispheres
does diffuse axonal injury show up on CT?
no, need MRI
head trauma followed by a slow progression of neurologic symptoms
subdural hematoma
located within brain parenchyma and has a rapid onset of symptoms
intracerebral hemorrhage
a subdural hematoma is caused by a ruptured […]
dural bridging vein
an epidural hematoma is caused by rupture of the […]
middle meningeal artery
intraparenchymal hemorrhage can be caused by rupture of the […] arteries
lenticulostriate
risk factors for subdural hemorrhage [3]
extremes of age (old and young)
alcoholism
anticoagulation use
hyperdensity within the tissue of the brain on CT with acute onset of symptoms
intraparachymal hemorrhage
[…] hemorrhages are located in the midbrain and pons and are a result of downward herniation of the brain
Duret
[…] herniation will typically cause progressive findings that begin with anisocoria
uncal
[…] herniation may cause changes in mentation or focal motor findings, but will typically not cause pupillary findings
subfalcine
[…] herniation results in the compression of the medulla or upper spinal cord
cerebellar tonsillar
[…] herniation may cause respiratory symptoms, lethargy, or paralysis but not pupillary findings
cerebellar tonsillar
herniation of the brain through a skull defect
transcalvarial
sudden onset of worst headache of their life and meningismus
subarachnoid hemorrhage
most common etiology of subarachnoid hemorrhage
ruptured anuerysm
typical causes of secondary brain injury [5]
acidosis
cerebral edema
free radical formation
ischemia
neurotransmitter release
what elements are required for diagnosis of concussion [2]
force
altered neurologic status
is aphasia a symptom of concussion?
no
common symptoms of concussion
blurred vision
difficulty with balance
loss of consciousness
post-traumatic amnesia
prolonged symptoms related to concussion
post-concussion syndrome
most common risk factor of intraparenchymal hemorrhage
hypertension
what type of hydrocephalus can subarachnoid hemorrhage, meningitis, and leptomeningeal carcinomatosis cause?
communicatings
often secondary to skull fracture involving the pterion
epidural hematoma
might present with transient loss of consciousness, followed by recovery, then rapid deterioration
epidural hematoma
does not cross suture lines
epidural hematoma
can cause transtentorial herniation and CN III palsy
epidural hematoma
rupture of bridging veins
subdural hematoma
type of hematoma in shaken baby syndrome
subdural hematoma
crosses suture lines
subdural hematoma
bleeding due to trauma, rupture of aneurysm, or AV malformation
subarachnoid hemorrhage
rapid time course
“worst headache of my life”
bloody/yellow LP
subarachnoid hemorrhage
increases the risk of developing hydrocephalus
subarachnoid hemorrhage
most commonly caused by systemic hypertension
intraparenchymal hemorrhage
seen with amyloid angiopathy, such as in AD
intraparenchymal hemorrhage
most often occur in the lenticulostriate vessels
intraparenchymal hemorrhage
traumatic shearing of the white matter tracts during rapid acceleration of the brain
diffuse axonal injury
shear injury often resulting in coma or vegetative state
diffuse axonal injury
MRI show multiple lesions involving white matter tracts
diffuse axonal injury
fluid accumulation in the brain parenchyma causing increased ICP
cerebral edema
cerebral edema is caused by osmotic shift
cytotoxic
common causes of cytotoxic cerebral edema [3]
early ischemia
hyperammonemia
SIADH
cerebral edema caused by extracellular fluid accumulation due to disruption of BBB
vasogenic edema
