Traumatic Brain Injury Flashcards
causes of tbi
vehicle crashes, falls, firearms, sports/recreation, others
common ages and groups at risk for tbi
<5 yo, 15-24 yo, >70 yo
males, 0-4 yo, 15-19 yo, >75 (most hospitalization and deaths)
coup vs contrecoup forces
coup: produce effects at or near impact site
contrecoup: remote from the area of impact (opposite side)
> 2 sqin vs <2 sqin objects
> 2 sqin: localized skull bending immediately beneath the impact point
<2 sqin: penetrating injury
examples of local effects
linear fractures (hairline crack) depressed fractures epidural hematoma subdural hematoma coup contusion
examples of remote contact effects
due to skull distortion or stress waves
remote vault fractures
what are inertial injuries: shearing and vessel injury
differential movement of the skull and brain produced by head acceleration
(brain lags behind skull for a brief moment after acceleration begins)
can tear bridging vessels, and cause structural or functional brain damage
types of head acceleration
translation (linear)
rotation
angular (most damaging)
what are bridging veins
parasagittal bridging veins connect brain and sagittal sinus
located in subdural space
what are inertial injuries: parenchymal injury
strain manifesting as classic “cerebral concussion”, diffuse axonal injury, hemorrhage, and contrecoup contusions
types of parenchymal injuries
shear* (different directions)
forward backward affects projection fibers
side to side affects commissural fibers (in corpus callosum)
rotational affects association fibers (front to back)
primary vs secondary brain damage
primary: effects of actual trauma on the brain at the moment of injury (not preventable)
secondary brain damage: complication of primary brain damage, usually inc icp
categories of brain injuries
skull fracture focal injury diffuse injury penetrating injury blast injury
types of skull fractures
open (compound) closed (simple) depressed diastatic basilar
t/f open fractures require more aggressive treatment
true, due to exposure to external environment
indications for nonsurgical intervention in closed fractures
not depressed
linear type for fracture
indication for surgery in depressed fractures
if depressed fracture is greater than thickness of calvaria and those not meeting criteria for nonsurgical management
indications for non-surgical management in depressed fracture
no evidence of dural penetration no significant intracranial hematoma depression <1 cm no frontal sinus involvement no wound infection or gross contamination no gross cosmetic deformity
t/f elevating depressed fractures can reduce post traumatic seizures
false, no evidence of this
DEPTH OF FRACTURE correlates to how much pressure on brain
what are fractures through suture lines called
diastatic fractures
types of petrous bone fracture
longitudinal fracture through petrosqumousal suture
transverse fracture: perpendicular to eac –> cn 7 and 8 defects, peripheral facial palsy
what are postauricular ecchymoses called
battle’s sign
management of csf leak at eardrum
slow type of bleeding: venous origin = can be stopped with pressure
put cotton ball in ear (tamponade effect)
refer to neurosurgeon/ent
tx for basilar skull fracture
prophylactic antibiotics
specific treatments
key sign of frontal sinus fractures
pneumocephalus –> dural laceration
what is a cerebral contusion
due to damage on small blood vessels on brain surface
t/f contusions can expand over time
true, require monitoring
monitor icp to prevent contusions from expanding and deteriorating brain
types of contusions
coup
contrecoup
intermediate coup: deep within neural parenchyma between impact and opposite side of the brain
indications for surgery of hemorrhagic contusion
progressive neurological deterioration referable to contusion
volume > 30 cc
frontal or temporal contusion >20 cc, WITH MIDLINE SHIFT >/=5 MM, compressed basal cisterns
common area for epidural hematomas
temporoparietal regions, middle meningeal arteries and diploic veins
limited by suture lines
classic presentation of epidural hematoma
brief post-traumatic loss of consciousness
lucid interval of a few hours
obtundation, contralateral hemiparesis, ipsilateral pupillary dilatation
common causes of subdural hematoma
accumulation around parenchymal lacerations (from laceration of bridging veins/superficial vessels)
surface of bridging vessels torn from cerebral acceleration-deceleration during violent head motion
indications for surgery in acute subdural hematoma
asdh with thickness >10 mm or midline shift >5 mm
OR
gcs drops by 2 points & icp >20 mmhg
ct scan findings in chronic subdural hematoma
crescentic mass of increased attenuation adjacent to inner table
t/f there may be gradual or repeated bleeding from neo membranes in chronic subdural hematoma
true
what is a diffused brain injury
occurs without macroscopic damage
most prevalent cause of disability in TBI survivors
mildest form: concussion
most severe: diffuse axonal injury
presentation of concussion
transient loss of consciousness, no visible structural damage but there is disturbance in brainstem or cortex
t/f in diagnosing concussion the patient should have shown signs of recovery before the 24th hour
true
category 1 for concussion
cantu: pta <30 mins, no loc
aan: transient confusion, no loc, symptoms resolve in <15 mins
category 2 for concussion
cantu: pta >30 mins, loc <5 mins
aan: transient confusion, symptoms resolve in <5 mins, no loc, (+) pta
category 3 for concussion
cantu: pta >24 hrs, loc >5 mins
aan: any loc
management of post-concussion syndrome
symptomatic
reassure patient that symptoms will resolve in 4-6 weeks
definition of diffuse axonal injury
clinicopathologic syndrome in patients unconscious form the time of trauma with widespread traumatic damage throughout the brain in the absence of intracranial lesion with mass effect
disrupted connections of axons
histologic findings in dai
axonal swelling, disruption of axons, retraction balls, punctate hemorrhages in pons midbrain and corpus callosum
dai classification
1: axonal injury of parasagittal white matter of cerebral hemisphere
2: grade 1 + focal lesion in corpus callosum
3: grade 2 + focal lesion in cerebral peduncle
mild, mod, and severe dai
mild: coma 6-24 h
mod: gcs 6-8 and coma >24 h
sev: gcs 4-5 and coma >24 h
t/f dai does not mean severe traumatic injury
false
what are retraction balls
twisted, stretched, and lost connection of axons which retract
found in: corpus callosum, periventricular white matter, basal ganglia, brainstem
presentation of subarachnoid hemorrhage
no inc icp
severe headaches
nape pain (irritated meninges)
spontaneous resolution in 2-3 wks
what is intracranial hypertension
persistent elevation of icp above 20 mmhg for >5 mins (poor outcome)
normal cerebral perfusion pressure
60-65 mmhg
45-55 = ischemia <45 = neuronal death
pressure monitoring objectives
maintain map 75-100
keep icp <15 mmhg
cpp 60-70 mmhg
cpp = map-icp
t/f when it’s not possible to intervene surgically or to relieve the pressure, patients are sedated and place in a coma
true, to reduce the metabolic demands of the brain
what is the carotid cut off sign
contrast only reaches level of mandible, aca and mca do not appear on angiogram due to compression
can be seen in extreme increase of icp
hallmarks of uncal herniation
ipsilateraly pupillary dilation (cn 3)
kernohan’s notch: false localizing paradoxical ipsilateral hemiparesis
gcs table
table 4, page 11
cushing’s triad
increasing bp, decreasing hr, decreasing rr
indications for ct scan
<15 gcs 2 hrs post op evident head injury seen clinically otorrhea or rhinorrhea suspect for basal skull fracture has repeated vomiting episodes >65 yo
indicators of prognosis in severe tbi
gcs score age pupillary diameter and light reflex hypotension ct scan features
