Alvarez- CSF Flashcards
CSF id formed in the _________ by both ______ and ______
Choroid plexus by both filtration an active transport
normal volume of CSF
125-150 mL
where is CSF contained?
20% in ventricles and rest in subarachnoid space
CSF circulates from the lateral ventricles into the third ventricle then the fourth ventricle via the ________
cerebral aqueduct
The CSF if propelled along the _______ by a cranio-caudal pulsate wave induced by flow in cerebral arteries
neuroaxis
_________ are cerebral arteries adn the associated EXPANSIONS of the vascular compartment on the cranial vault
wave
where is CSF reabsorbed
arachnoid villi
what position should patient be to measure the CSF pressure?
flat in the lateral decubitus position
normal CSF pressure range
60-250 mm H2O
what would cause CSF to look turbid?
min 200 WBC or 400 RBC/microL
what would cause CSF to appear bloody?
6000 RBC
what happens to RBC (hemoglobin) when enters the CSF? (biproducts)
it is lysed
Hemoglobin –> oxyhemoglobin (pink) –> bilirubin (yellow) –> xanthochromia
yellow or pink discoloration of CSF is called?
xanthochromia
unexplained xanthochromia can be due to
tramuatic tap
normal amount of WBC’s and PMNs in CSF
5 WBC –> normal
>3 PMNs –> abnormal
when can CSF cell determination be falsely low?
if measured more than 60 min after LP
what is pleocytosis
an elevated CSF WBC concentration
patients with meningitis have high ______ in 2/3 of patients
PMNs (then changes to high lymphocytes after 12-24 hrs)
early –> PMNs
Late –> lymphocytes
good rule of thumb to calc. WBC count in a traumatic tap
subtract 1 WBC for every 500- 1500 RBCs
CSF protein can be elevated by a _______ or _____
subarachnoid hemorrhage or traumatic LP
when are immunoglobulins and oligoclonal bands found in CSF
in Multiple sclerosis (also in lyme, autoimmune, brain tumors, lymphoproliferative diseases )
what is hypoglycorrhachia
low CSF glucose
CSF glucose concentrations less than 18 mg/dL are strongly predictive of
bacterial meningitis
normal CSF to glucose ratio
> .6
Useful test to differentiate bacterial from viral meningitis
lactate concentration
type of meningitis: WBC less than 2000 shows predominance of lymphocytes (in late)
viral
type of meningitis: WBC above 1000 with a neutrophilic predominance
Bacterial
type of meningitis: CSF protein is less than 150 mg/dL
Viral
type of meningitis: CSF protein concentration 250
bacteral
type of meningitis: glucose CSF concentration is more than 50 of serum concentration
Viral
type of meningitis CSF glucose is below 45 mg/dL
bacterial
how do you diagnose a subarachonid hemorrhage
when xanthochromia is detected as soon as 2-3 hours after RBCs have entered subarachnoid space
