Cerebrospinal Fluid Flashcards
what are the two most routinely used techniques for measuring total CSF protein
turbidity production or dye binding ability
WBC that is common in cases of viral, tubular and fungal meningitis
Lymphocytes and Monocytes
three main meninges
Dura, mater, arachnoid, pia mater
WBC seen in serious complication of acute leukemias
Lymphoblasts, myeloblasts and monoblasts
Acid-fast or fluorescent antibody stains can identify
possible tubercular
meningitis
why do CSF glucose specimen be tested immediately
because glycolysis
occurs rapidly in CSF
from the lining of the ventricles and neutral canal
ependymal cells
routinely used for performing CSF
cell counts
Neubauer counting chamber
yellow hematoidin crystals represent
further degeneration
Specimens are collected in three sterile tubes, which are labeled 1,
2, and 3 in the order in which they are withdrawn. specify the three tubes
Tube 1: for Chemical and Serologic tests because these tests
are least affected by blood or bacteria introduced as a result
of the tap procedure.
Tube 2: Microbiology Laboratory
Tube 3: for Cell Collection, because it is the least likely to
contain cells introduced by the spinal tap procedure
produced from ammonia and a-ketoglutarate by the
brain cells
Glutamine
these may not present in serum but neurologic disorder that produce
oligoclonal banding
encephalitis, neurosyphilis, Guillain-Barré
syndrome, and neoplastic disorders
Increased glutamine means there is
increased ammonia (toxic to CNS)
represent lining from the arachnoid
may be seen with systemic malignancies
spindle-shaped cells
Cells from primary CNS tumors include
astrocytomas,
retinoblastomas, and medulloblastomas
during viral infection in conjunction with normal cell. what is the appearance of lymphocytes
Reactive lymphocytes containing increased dark blue cytoplasm
and clumped chromatin
abnormally low values of CSF protein indicates
fluid is leaking from the CNS
provide a more sensitive method than the India ink
preparation
Latex agglutination tests:
detects oligoclonal bands, which represent inflammation within
the CNS
Electrophoresis and Immunophoretic Techniques
causes of elevated CSF protein
- damage to the blood–brain barrier
- immunoglobulin production within the CNS
- decreased normal protein clearance from the fluid
- neural tissue degeneration
source of CSF
where CSF is made and produced
Choroid plexuses
normal CSF volume in neonates/infant
10-60 ml
reference value of CSF glucose
60% to 70% plasma glucose
detect the presence of neutrosyphilis
Serologic Testing
recommended serologic test
Venereal Disease Research Laboratories (VDRL)
ar
normal opening pressure for infants and young children
90-180 mm of water in lateral
10-100 mm of water → attains adult level by 6-8 years
degradation of the phagocytized RBCs appears
Dark blue or Black iron containing hemosiderin granules
known as gentle mother
a thin membrane lining the surface of the brain and spinal cord
pia mater
what causes the presence of Xanthochromia
presence of RBC degradation products
microbiology method for CSF
Gram stain, acid-fast stain, India ink preparation, and
latex agglutination tests
where can you collect or what part of the body can you collect CSF
third, fourth or fifth lumber vertebra
what solution to lyse RBC
3% glacial acetic acid
what causes Low CSF glucose
alterations in the mechanisms of glucose
transport across the blood–brain barrier and by increased
use of glucose by the brain cells
protein index value of <9 is indicative/represent
represents an intact blood brain barrier
what to do If >200 mm H2O opening pressure
no more than 2 ml withdrawn
Elevated pressure = withdraw fluid slowly
WBC that are seen in the early stages (1-2 days) of viral, fungal, tubercular and parasitic meningitis
Neutrophils
what tube is to be collected first if there is only one tube collected
Microbiology
two or more oligoclonal bands that are not present in the serum is indicative of
multiple sclerosis (particularly when accompanied by an increased
IgG index)
provides a highly concentrated specimen for Gram
stains
Cytocentrifuge
normal CSF produced in adults
20 ml/hr (Henry’s: 0.3-0.4 ml/min)
normal opening pressure for adults
90-180 mm of water
decubitus position
High CSF WBC count neutrophils indicative of
bacterial meningitis
> 35mg/dL CSG glutamine causes
disturbance of consciousness
csf protein > 0.70 is indicative of
IgG production within the CNS
Recommended Method for diff count in all body fluids
Cytocentrifugation
in cytocentrifuge, what stain and solution is currently bein used
0.2 mL saline and two drops of the 30% albumin
normal CSF appearance
Crystal-clear
concentration of ammonia in the CSF increases result in
a. supply of a-ketoglutarate becomes depleted
b. glutamine can no longer be produced to remove the toxic
ammonia
c. coma ensues
what causes false elevated results in CSF lactate
xanthochromic or
hemolyzed fluid
in cytocentrifuge. what should be done if there is to many cells on one slide
repeat chamber count
appear within 2 - 4 hrs after RBCs enter the CSF and are frequently seen following repeated taps
Macrophages
normal volume in adults
90-150 ml in adults
> 25mg/dL of CSF lactate is indicative of
bacterial, tubercular, and fungal meningitis
increase macrophage indicates
previous hemorrhage
> 35mg/dL of CSF lactate is indicative of
bacterial meningitis
specimen storage for csf according to the three tubes
Hematology tubes: refrigerated
Microbiology tubes: room temperature
Chemistry and serology: frozen
arachnoid granulations act as
act as one-way valves that
respond to pressure within the central nervous system (CNS) and
prevent reflux of the fluid
detect the presence of C. neoformans
antigen in serum
Latex agglutination tests
provide a rapid method for detecting C.
neoformans
Lateral Flow Assay (LAF)
what are the Three visual examinations of the collected specimens can usually
determine whether the blood is the result of hemorrhage or a
traumatic tap
Uneven Blood Distribution, Clot Formation and
Xanthochromic Supernatant
Its presence indicates recent destruction of the myelin sheath that
protects the axons of the neurons (demyelination)
Myelin Basic Protein
what causes orange xanthochromia
heavy hemolysis
increase protein or lipid concentration, may also indicate infection
Cloudy/turbid
what stains the WBC
methylene blue - providing better differentiation between neutrophils and
mononuclear cells
to measure IgG synthesis within the
CNS
CSF IgG index
what is the purpose of a macrophage
remove cellular debris and foreign objects such
as RBCs
supernatant that is pink, orange, or yellow
Xanthochromia
High CSF WBC count lymphocytes and monocytes indicative of
meningitis of
viral, tubercular, fungal, or parasitic origin
what are cells normally found in CSF
Lymphocytes and monocytes
it is still the recommended method for detecting
MOs
Gram stain
capillary networks that form the CSF from
plasma by mechanisms of selective filtration under hydrostatic
pressure and active transport secretion
Choroid Plexuses
what causes yellow xanthochromia
conversion of oxyhemoglobin to unconjugated bilirubin
what should be done to To ensure that the maximum number of cells is available for
examinating
the specimen should be concentrated before
preparing the smear
Low CSF glucose indicates
considerable diagnostic value in determining the
causative agents in meningitis
most common cause
of false-positive reactions in latex agglutination test
Interference by rheumatoid factor
what indicates a pink Xanthochromia
very slight amount of oxyhemoglobin
most frequently associated with its role in providing
diagnostic information about the type of microorganism that
is causing an infection of the meninges (meningitis)
Pleocytosis
Total CSF volume is replaced every (hours, minutes, days)
5 - 7 hours
what indicates If WBC are lymphocytes
tubercular meningitis is suspected
most frequently encountered bacteria in CSF
- Streptococcus pneumoniae (gram-positive cocci)
- Haemophilus influenzae (pleomorphic gram-negative rods)
- Escherichia coli (gram-negative rods)
- Neisseria meningitidis (gram-negative cocci)
the result of blood that has been present longer than that introduced by the traumatic tap when RBCs remains in the CSF for approximately 2 hours before noticeable hemolysis begins
Xanthochromic Supernatant
presence of increased numbers of normal cells is
considered abnormal, as is the finding of immature leukocytes,
eosinophils, plasma cells, macrophages, increased tissue cells, and
malignant cells
Pleocytosis
Dilutions for total cell counts are made with
Dilutions for total cell counts are made with normal saline →
mixed by inversion → loaded into the hemocytometer with a
Pasteur pipette.
what causes false-negative in gram stain for CSF
Overlooking MOs due to low number
two types of grossly bloody CSF
Intracranial hemorrhage and traumatic top
where the circulating fluid is
reabsorbed back into the blood capillaries
Arachnoid Granulations/Villae
what causes false-positive in gram stain for CSF
- Precipitated stain or debris mistaken for MOs
- false-positive reports can occur if precipitated stain or debris
is mistaken for microorganisms
Differentiate intracranial hemorrhage and traumatic tap
intracranial hemorrhage
- blood will evenly distributed throughout three CSF specimen tubes
- Not enough fibrinogen to clot
traumatic tap
- heaviest concentration of blood in tube 1, less in tube 2 and tube 3
- forms clot due to presence of plasma fibrinogen
what must be made in order to determine whether IgG is increased
because it is being produced within the CNS or is elevated as the
result of a defect in the blood–brain barrier
comparisons between serum and CSF levels of albumin and IgG
Supply nutrients to nervous tissue
Remove metabolic wastes
Mechanical barrier to cushion brain and spinal cord against trauma
Physical support (lessens weight)
Pathywayfor hormones and other substances from the
hypothalamus to mediameminence
CSF
commonly use in detecting and identifying microorganisms in CSF
Latex agglutination and enzyme-linked immunosorbent assay
(ELISA)
Normal CSF glucose value with increased number of lymphocytes is indicative of
viral meningitis
serves to remove the toxic metabolic waste product ammonia
from the CNS
Glutamine
located between the arachnoid and pia mater
Subarachnoid space
a test that analyzing CSF is to identify the causative agent in meningitis
microbiology test
Motile trophozoites can be observed microscopically by
examining a wet preparation of CSF
Naegleria fowleri
increase lymphocytes is indicative of
asymptomatic HIV infection and AIDS
elevated WBC count (less than 50 WBCs/ L) with increased normal
and reactive lymphocytes and plasma cells = multiple sclerosis or
other degenerative neurologic disorders
known as the hard mother
is the outer later of the meninges that lines the skull and certebral
Dura mater
why is cell count on CSF be performed immediately
because WBCs
(particularly granulocytes) and RBCs begin to lyse within 1 hour,
and 40% of the leukocytes disintegrate after 2 hours
detect the presence of thickly encapsulated Crypto coccus
neoformans
India Ink
< 25mg/dL of CSF lactate is indicative of
viral meningitis
frequently used to monitor severe head injuries
CSF Lactate
how can you remove a volume of CSF
volume of CSF that can be removed is based on the volume
available in the patient (adult vs. neonate) and the opening
pressure of the CSF, measured when the needle first enters the
subarachnoid space
Up to 20 ml of CSF may normally be removed
a WBC cell count in CSF that has an automation increases precision, standardization, and faster
turnaround time for results
Neubauer counting chamber
These techniques are also the method of choice when
determining whether a fluid is actually CSF - More sensitive, Better resolution, Does not require specimen
concentration
CSF immunofixation
electrophoresis (IFE) and isoelectricfocusing (IEF) followed by
silver staining
How to monitor Myelin Basic Protein
measuring the amount of MBP in the CSF
Gram stain for possible fungal meningitis appears
classic starburst
appearance
a test in identifying bacteria in CSF that is not as sensitive to N. meningitidis
as it is to the other organisms
Bacterial antigen test (BAT)
cell that is routinely performed don CSF
Leukocyte (WBC)
Markedly Decreased CSF glucose accompanied by an increased
WBC count and a large percentage of neutrophils is indicative of
bacterial
meningitis
neutrophil with pyknotic is indicative of
degenerating cells
method used for Myelin Basic Protein
Immunoassay
Normal concentration of glutamine in the CSF
8 - 18 mg/dL
India ink can detect/identify
possible fungal meningitis
routinely performed on CSF from all suspected cases of
meningitis, although its value lies in detecting bacterial and fungal
organisms
Gram Stain
known spiderweb-like
a filamentous inner memberane
arachnoid
why is CSF Gram stain is one of the most difficult slides to interpret
because the number of organisms present is usually small, and they
can easily be overlooked, resulting in a false negative report
Preferred method for CSF glutamine
direct measurement of CSF ammonia
normal WBC count CSF for newborn
30 mononuclear cells(WBC)/uL
a tight-fitting structure of the endothelial cells in the choroid
plexuses
Blood-brain barrier (BBB)
normal WBC count CSF for adult
0 - 5 WBC/uL
Elevated levels of CSF glutamine is associated with
liver disorders that result in
increased blood and CSF ammonia
protects the brain from chemicals and other substances circulating the blood that could allow the brain tissue
Blood-brain barrier (BBB)
what causes increase CSF lactic acid level
hypoxia
in cerebrospinal protein, what should be done in low protein level specimen
specimen must be concentrated
first
not recommended serologic test
Rapid plasma regain (RPR) test
ratio of predominant leucocytes to monocytes in adults
70:30
elevated CSF protein is indicative of
Meningitis and hemorrhage conditions that damage the bbb
during cytocentrifuge, what solution is added/combined to a 0.1 mL of CSF to produce an adequate cell yield
one drop of 30%
albumin
to examine a bloody fluid for the presence of xanthochromia:
fluid should be centrifuged in a microhematocrit tube and
the supernatant examined against a white background
if found in the epithelial lining of the choroid plexus
Choroidal cells
laboratory method that separates proteins
based on their physical properties
Electrophores
in cytocentrifuge. what should be done if there is to little cells on one slide
prepare new slide
