TBI Flashcards
TBI subtypes (spectrum)
concussion, contusion, intracranial hemorrhage/intracerebral hemorrhage…. death
anywhere throughout the spectrum, it is possible to suffer from:
DAI: As tissue slides over tissue, a shearing injury occurs. This causes the lesions that are responsible for unconsciousness, as well as the vegetative state that occurs after a severe head injury. A diffuse axonal injury also causes brain cells to die, which cause swelling in the brain.
primary biochemical force that induces concussion?
Rotation/angular acceleration (if I hit a wall, no concussion, if someone snaps my head around from being hit in the face, the rotation/angular acceleration will cause a concussion)
characteristics of a concussion?
Zurich Consensus Guidlines 2012:
the ZCC define concussion as:
- Direct or impulsive force
- Rapid onset
- Functional
- Clinical symptoms
- No abnormality on standard imaging
macro biomechanics: the places that we see the highest shear force:
corpus collosum, amygdala, hippocampus: all places you see the greatest change in clinical setting
microscopic biomechanics
shearing axon
when you twist a cell membrane:
the semipermeable membrane is fully open
two ions that freely flow through the membrane upon concussion :
glutamate and Ca2+, glutamate is semi-toxic to the brain and Ca2+ causes a tidal wave of action potential
concussion is a
mechanical injury that leads to a chemical change
the mechanism for a concussion includes:
k/na pump dysfunction, ca influx, eaa release, spreading electrical depression, reversion to glycolysis for pump restoration, rely on glyscolysis for restarting system
contusion:
this is concussion, PLUS, mainly in frontal and occipital
on mri, contusion will show:
edema in front, occipital or parietal
70 yr old woman falls, has pain in left occipital and feels out of it. What test is most appropriate?
concerned with bleeding in the brain so CT (sensitive for blood)
subdural hemorrhage:
venous blood/low pressure, under dura, tearing of bridging veins: all the problems from before plus chemical changes (apoptosis) and “Mass effect”
mnemonic for subdural hemorrhage:
ABCDE:
Alcoholics (brain shrinks and puts strain on bridging veins that run from the top of the skull to the brain)
Bridging veins
Crescent shaped on CT
Dura intact
Elderly (falls, atrophy of brain, and anti-coagulants like cumin)
14 yr old takes line drive to temple, loss of consciousness, seems fine, then vomiting and is difficult to keep awake. What do you see on CT?
young (not as much of a subdural risk)
temple is thin, just above middle meningial artery
high pressure bleed in brain:
epidural hemorrhage: arterial blood, high pressure, only place for the brain to go is down, presses on foramen magnum, crushes brain stem which is responsible for breathing
epidural hematoma characteristics:
skull fracture, middle meningeal artery, mass effect
epidural mnemonic:
FLAIR Fracture (temporal) Lens-shaped on CT Arterial (middle meningeal) Interval (lucid interval) Ripped dura
subarachnoid mnemonic:
Circle of Willis on CT Headache (thunderclap) Arterial blood/aneurysm Nausea, neck stiffness Trauma Seizures or syncope
arterial blood, high pressure, severe (hypertension or dramatic trauma ( like being beaten by a lead pipe)
TEST: which type of brain injury is most likely to cause seizures:
subarachnoid the death star Circle of Willis on CT Headache (thunderclap) Arterial blood/aneurysm Nausea, neck stiffness Trauma Seizures or syncope
intracerebral hemorrhage:
intraparenchymal and intraventricular, arterial and severe, from: trauma hypertension AVM and rapid bleeding
4 areas to remember on assessment: history
thinking/remembering, physical, emotional mood, sleep disturbances, even 1 from each category is debillitating
