Week 2: Nervous system anatomy/disorders (Injuries, Hematomas, ICP) Flashcards
What is a mild brain injury
bruising of the tissue
what is a severe brain injury
destruction of the brain tissue
swelling of the brain
what is a concussion
mild traumatic brain injury result of mild blow to head
reversible interference with brain function
amnesia and headaches can follow
usually recover within 24h w/o perm. damage
what occurs in brain when a concussion happens
sudden excessive movement in the brain disrupted neurologic function and a loss of conciousness
whats a contusion
result from blunt blow in head
bruising of brain tissue and rupture of small blood vessels and edema
possible residual damage
what causes residual damage when contusion occurs
regen of scar tissue
whats a closed head injury
skull not fractured
brain tissue injured
blood vessels may rupture
extensive damage can occur when head roates
whats an open head injury
fractures
penetration of brain
by sharp objects
what are depressed skull fractures
displacement of piece of bone below level of skull
- compression of brain tissue
- blood supply to area imparied
whats a basilar fracture
occur at base of skull
leaking of CSF through ears or nose
ex. when forehead hits winsheild car accident
whats a contrecoup injury
area of brain contralateral to site of direct damage when brain bounces off skull
ex. acceleration/ deceleration injuries
how can you tell the diff. btwn normal nasal discharge and CSF
consistency
CSF has glucose
primary brain injuries
involve laceration/compression of brain tissue
unusual force can rotate/shift brain inside skull
ex. mvmt. of lobes against eachother
damage by rough/irregular inner surface of skull
piece of bone/foregin object
rupture or compression of cerebral bl.vess.
secondary brain injuries
result from additional effects of
- cerebral edema
- hemorrhage
-hematoma
-cerebral vasospasm
-infection
-ischemia related to systemic issues
what does trauma to brain tissue cause
loss of function in part of body controlled by that area of brain
what does cell damage and bleeding lead to
inflammation, vasospasm around inury site
icp
ischemia
dysfunction
what does vasospasm cause
lack o2
vessels shrink (constriction)
what are hematomas
relation to meninges
epidural hematoma
bleeding btween.
dura and skull
-signs arise within a few hrs of injury when a patient loses consciousness after period of responses
whats a subdural hematoma
bleeding btwn.
dura and arachnoid
-acute 24h
-subacute 1wk
-tear in arachnoid
what does tear in arachnoid allow
CSF to leak into subdural space
creating additional pressure
whats a subarachnoid hemorrhage
bleeding btwn
arachnoid and pia
-traumatic bleeding from bl.vess. at base of brain
-blood mixes w CSF- not localized hematoma
whats an intracerebral hematoma
results from contusions or shearing injuries
may develop several days after injury
what do all types of hematomas lead to
local pressure on adjacent tissue
increase in icp
what are signs and symproms of hematomas
focal & general signs of increased ICP
seizures
cranial nerve impariement
otorrhea
rhinorrhea
fever
whats a fever sign of in relation to hematomas
hypothalmic impairment or cranial systemic infection
what can be used to determine the extent of brain injury
ct
mri
glucocorticoid agents
decrease edema
antibiotics
reduce risks of infection
surgery
reduce icp
blood products and o2
used to protect remaining brain tissue
what within the brain is not compressible
skull
fluids
blood
CSF
increase of fluid or additional mass causes what?
increase pressure in brain
what happens when their is increased pressure in brain
ischemia and infarction of brain tissue
what is the cycle of increased ICP
increased ICP
vasoconstriction
inflammatory response
vasodilation
increased blood supply to brain
increased fluid in brain
hematoma growth occurs
whats the pathophysiology behind increased ICP
body first tries to shift CSF out of brain by increasing venous return
hypoxia occurs, this causes vasodilation through autoregulation effect
this increases fluid in skull
what are early signs of increased ICP
decreased conciousness/responsiveness
severe headache
vomiting
papilledema
why does severe headaches occur when ICP increases
stretching of dura and walls of large vessels
what is vomiting a result of when ICP increases
pressure stimulating emetic center in medulla
why does papilledema occur
increased ICP and swelling of optic disc
what affects size and response of pupils
pressure on oculomotor nerve
whats ptosis
droppy eyelid
what are visual signs of increased ICP
ipsilateral pupil
ptosis
what area the componenets of the cushings reflex of cushings triad
systolic hypertension
decrease HR
decrease RR
why does systolic hypertension occur
systemic vasoconstric to pump more blood to brain to relieve ischemia
why does HR decrease
by baroreceptor in carotid arteries in response to high BP
why does RR decrease
by chemoreceptors bcz of low co2
why does only systolic BP increase
bcz of slow HR and intermittent cushing triad
what is significant in ppl w ICP
increase Pulse pressure
what occurs if ICP is not relieved
drop in BP
RR control destroyed
cheyne strokes respiration
why does bp drop if icp is not relieved
loss of circulatory control with severe ischemia and neruonal death
why are respiratory controls destoryed when ICP is not releived
herniation pushes donw on brain stem
what are cheyne stokes respiration
alternating apnea and periods of increased and decreasing respirations
whats elevated when icp is increased
pressure of CSF
whta does it mean when CSF is pink
contains erythrocytes RBC
what does it mean when CSF is cloudy and yellow
contains WBC
what may abnormal protein levels indicate
neoplasm
contents moved from one place to another through a membrane
herniation
