CSF Analysis Flashcards
autoimmune disease of the CNS
ALS
SLE
MS (demyelinating disorders)
Neurosyphilis
how do you obtain CSF?
lumbar puncture from subarachnoid space
where is the CSF produced?
choroid plexus of the ventricles
what are the roles of CSF?
transports nutrients
clears metabolic waste
what could blood in the tap indicate?
subarachnoid hemorrhage will not clot
traumatic tap will clot
what could cloudy CSF mean?
presence of WBC or protein
what could xanthochromia of the CSF mean?
yellow tinge
hyperbilirubinemia
hypercarotenemia
melanoma
elevated PMNs means
bacterial meningitis or cerebral abscess
what 4 tubes do you send in a CSF analysis?
culture
cell count, cytology
pH, protein, glucose, chloride
serology
common bacterial meningitis causers
H. influenzae
neisseria meningitis
S. pneumonia
common viral meningitis causers
herpes simplex
coxsackiervirus
echovirus
infectious mono
should protein be in CSF?
no, BBB should not allow it to cross
some disease can alter the permeability and allow protein to leak into the CSF
why is glucose important to the brain?
brain doesn’t produce or store its own glucose
how do bacteria, inflammatory cells, and tumors impact glucose in CSF?
decreased
how do you test CSF glucose?
compare to serum glucose (drawn prior to LP)
should be >60% of serum
how will bacteria and fungal infection impact lactic acid in CSF?
increased
indicates decreased oxygenation of the brain-anaerobic metabolism
which tests identify syphilis?
Wasserman
Venereal Disease Research Lab test
Fluorescent Treponamal antibody (most spec and sens)
how is chloride level different in the CSF?
it is higher
what type of white blood cell is normally in the CSF?
lymphocyte mostly
what would presence of mononuclear leukocyte indicate?
viral
TB
encephalitis
how will infection or TB affect chloride levels?
decrease
how would infection or inflammation impact LD levels?
increase (comes from WBC that are fighting bacteria)
what level might be low when lactic acid level is high?
glucose level
what other test is useful for the diagnosis of bacterial meningitis?
CRP of serum (sensitive)
