TBI - Lecture 14 Flashcards
acquired brain injury
injury to the brain at the cellular level resulting in a change in neuronal activity
what does injury to the brain affect
physical integrity
metabolic activity
fxnal ability of the neurons
ABI are
not hereditary, congenital, degenerative or induced by birth trauma
TBI is a _____ of ABI
subset
caused of ABI
TBI w/ or w/o skull fx
CVA
AVM
aneurysm
anoxic encephalopathy
intracranial tumors
meningitis, encephalitis
seizure disorders
toxic exposures
TBI is the
leading cause of neurologic disability in the US
incidence rate
highest
age 15-24
how often does someone sustain a TBI (US)
23 s
how many americans sustain a TBI/yr
1.4-1.5 mil
how many americans currently live with disabilities resulting from a TBI
estimated 5.3 americans
how many people die as a result of a TBI each year
> 50k
leading cause of death in children under 5
TBI
TBI
a non-degenerative, non-congenital insult to the brain from an external force
what can a TBI possibly lead to
permanent or temp impairments of cognitive, physical, and psychosocial fxns with an associated diminished or altered state of consciousness
which gender is more at risk for TBI
male
highest risk age
0-4 and 15-19
highest rates of TBI-related hospitalization and death
> age 75
certain military personel
at risk
IED exposure
elderly TBI
fastest growing group of TBI pts
anticoagulants
elder abuse
elderly –> high risk secondary to
medications
decreased balance
decreased strength
how many children sustain brain injuries a year
> 1 mill
TBI is the leading cause of death in children
<5
how many pediatric injuries are related to brain injuries
1/3
pediatric TBIs are often
misdiagnoses or misidentified
if TBI occurs b4 attainment of development milestones
the child might never attain those milestones
TBI pathology
primary and secondary injury
primary injury
focal
diffuse
focal
penetrating injury
non-penetrating injury
penetrating injury
skull fxs
lacerations
gunshot/missile wounds
non-penetrating injuries
concussion
contusion
intracranial hemorrhage
diffuse
diffuse axonal injury (DIA)
skulls fxs
the more the severe the TBI, the more likely for skull fxs
skulls fractures have
higher risk of seizures and intracranial hemotoma
what is secondary to CSF leak –> skull fx
rhinorrhea or otorrhea
contusions
hemorrhage
edema
tissue distortion
scarring
what do contusions produce
focal cognitive and sensori-motor deficits
increased risk of seizures
types of intracranial hemorrhages
extra-axial
intra-axial
extra-axial hemorrhages
epidural
subdural
subarachnoid
intra-axial hemorrhage
intra-parenchymal
intra-ventricular
imaging –> intracranial hemorrhage
CT scan
MRI
CT
preferred over MRI initially
better at detecting bony fxs, hematomas, SAH
easily accesible, faster, cheaper
MRI
more beneficial for detection of severe TBIs
epidural hematoma
mass effect
associated with skull fx common
where does a EDH occur
b/w skull and dura mater
where is a EDH most common
middle meningeal artery
EDH enlarges
fairly slowly
EDH can be dangerous d/t
increase in ICP
subdural hematoma occurs
b/w dura and arachnoid
SDH onset
variable
SDH is most commonly
traumatic in nature
SDH is
rupture of vein that bridge the subdural space
SDH v. EDH
SDH is more common
morbidity and mortality
greater in SDH than EDH
SDH is more common in people w/
brain atrophy - tension on bridging veins
higher risk of falls
anticoagulants
anticoagulants –> SDH
increase risk of hemorrhage even with minor injuries
subarachnoid hemorrhage location
b/w the arachnoid and pia
SAH seen
to a degree in most serious brain injuries
SAH –> sudden onset of
loss of consciousness
SAH has
increased risk of vasospasm
increased risk of hydrocephalus
SAH requires
immediate intervention
dangerous
intra-parenchymal
IPH
intracerebral or intracerebellar
intra-ventricular
IVH
usually seen with SAH
diffuse axonal injury (DAI)
acute stretching and shearing of axons
what are DAI caused by
shearing injury and accelerating and decelerating forces to the brain
DAI is a
microscopic diagnosis
where is DAI most often seen
corpus callosum
subcortical white matter
cerebral peduncles
brainstem
DAI in the midbrain
particularly repsonsible for initial LOC
DAI is associated with
shaken baby syndrome
DAI grading
mild
moderate
severe
mild DAI
coma lasting 6-24 hrs
mild-mod memory impairment and disabilities
moderate DAI
coma > 24 hrs
f/b confusion and long lasting amnesia
w/drawl to purposeful mvts
mod-severe memory, behavioral, cognitive and intellectual deficits
severe DAI
deep prolonged coma lasting months w/ flexion and extension posturing
severe deficits in all areas
DAI diagnosis
may see nothing on radiologic exam
petechial hemorrhages seen 20% of the time on CT scan
MRI is more sensitive imaging
MRI –> DAI
diffusion weighted imaging
FLAIR
gradient ECHO
diffusion tensor imaging
secondary injury
increased ICP
cerebral edema
hypoxia or anoxia
ischemia
hemorrhage, hematoma, herniation, mass effect
hypotension
neurochemical and cellular changes
electrolyte imbalances
ICP levels
ideal
abnormal
likely to have neurological damage
fatal
ideal
0-10
abnormal
20-40
likely to have neurological damage
> 40
fatal
> 60
increases ICP can cause
decreased cerebral BF
decreased CPP
herniations
interventions for increased ICP
surgical
pharmacological
surgical interventions –> ICP
decompressive surgery
CSF drainage
decreased intracranial volume
decompressive surgery
craniotomy
craniectomy
decreased intracranial volume
raise the HOB
hyperventilation (temp)
pharmacological
mannitol
barbiturate coma
hypoxia and edema
systemic brain damage
intracranial brain damage
systemic brain damage
arterial hypoxemia d/t airway obstruction or trauma
loss of brain’s ability to autoregulate vasodilation –> decreased cerebral perfusion
intracranial brain damage
cytotoxic edema
vasogenic edema
brain shift and hernitation
neurosurgical emergency
uncal herniation
temporal lobe gets pushed downward through the temporal notch
compressing the brainstem
central herniation
diencephalon is at risk
same as uncal herniation
cerebellar herniation
cerebellar edema pushes the cerebellar tonsils downward through the foramen magnum
compressing the brainstem
subfascial herniation
caused by an expanding frontal lobe lesion
