Strasinger_CSF Flashcards
1
Q
CSF Functions
A
- provides nutrients to nervous tissue
- removes metabolic wastes
- produces mechanical barrier to cushion the brain and spinal cord against trauma
2
Q
lines the brain and spinal cord
A
meninges
3
Q
3 meninges layers
A
dura mater
arachnoid
pia mater
4
Q
Which layer of the meninges lines the skull and vertebral canal
A
dura mater
5
Q
hard mother
A
dura mater
6
Q
which layer of the meninges is referred to as the spider-like filamentous inner membrane
A
arachnoid
7
Q
thin membrane lining the surfaces of brain and spinal cord
A
pia mater
8
Q
gentle mother
A
pia mater
9
Q
How much CSF is produced every hour
A
20 mL
10
Q
Where CSF is produced
A
choroid plexuses (of the two lumbar ventricles and the third and fourth ventricles)
11
Q
Where the CSF flows through
A
subarachnoid space
12
Q
where the subarachnoid space is located
A
between arachnoid and pia mater
13
Q
normal volume of CSF in adults
A
90-150 mL
14
Q
normal volume of CSF in neonates
A
10-60 mL
15
Q
how is CSF volume maintained?
A
the circulating fluid is reabsorbed back into the blood capillaries in the arachnoid granulations/villae at a rate equal to its production.
16
Q
arachnoid granulations:
one-way or two-way valve?
A
one-way:
The cells of the arachnoid granulations act as one-way valves that respond to pressure within the central nervous system (CNS) and prevent reflux of the fluid
17
Q
How is CSF formed?
A
Choroid plexuses form CSF from plasma by mechanisms of selective filtration under
hydrostatic pressure and active transport secretion
18
Q
T/F:
CSF does not resemble an ultrafiltrate of plasma
A
TRUE
19
Q
cells that line the capillary walls throughout the body
A
endothelial cells
: these are loosely connected to allow passage of soluble nutrients and wastes between the plasma and tissues
20
Q
tight-fitting structure of the endothelial cells in the choroid plexuses
A
blood-brain barrier (BBB)
21
Q
T/F:
Diseases such as meningitis and multiple sclerosis disrupts BBB
A
True
: this then allows leukocytes, proteins, and additional chemical to enter CSF
22
Q
procedure used for CSF collection
A
lumbar puncture
: between the third, fourth, or fifth lumbar vertebra
23
Q
T/F:
Lumbar puncture is a complicated procedure
A
FALSE
: Lumbar puncture is not complicated but may require certain precautions.
: requires measurement of intracranial pressure and technique to prevent infection or neural tissue damage
24
Q
number of tubes needed for CSF collection
A
3
25
Tube 1 from CSF collection is for:
chemical and serological tests
: frozen
: least affected by blood or bacteria introduced as a result of tap procedure
26
Tube 2 from CSF collection is for:
microbiology
27
Tube 3 from CSF collection is for:
cell count
: least likely to contain cells introduced by the tap
28
4th tube may be drawn from the CSF collection. This is for:
microbiology to better exclude skin contamination or for additional
serologic tests
29
T/F:
Excess CSF fluid drawn may be discarded
FALSE
Excess fluid should not be discarded and should be frozen until there is no further use for it.
30
Supernatant fluid left over after each section has performed its tests may be used for?
additional chemical or serologic tests
31
T/F:
CSF testing are ideally performed on a STAT basis
TRUE
32
Storage condition of CSF tube:
Hematology tubes
Refrigerated
33
Storage condition of CSF tube:
Microbiology tubes
Room temp
34
Storage condition of CSF tube:
Chemistry and serology tubes
Frozen
35
CSF appearance that may be a result of increased protein or lipid concentration and may be indicative of infection
cloudy, turbid, milky
36
If only one tube can be collected for CSF, where must it be tested first?
Microbiology
37
T/F:
It is not unusual for cell counts requested to be performed on both Tubes 1 and 4
TRUE
: this is to check for cellular contamination by the puncture
38
CSF supernatant is pink, orange, or yellow
Xanthochromia
39
most common cause of xanthochromia
presence of RBC degradation products
40
CSF color that would indicate there is a very slight amount of oxyhemoglobin
pink
41
CSF color that would indicate heavy hemolysis
orange
42
CSF color that would indicate conversion of oxyhemoglobin to unconjugated bilirubin
yellow
43
Other causes of xanthochromia other than presence of RBC degradation products
* elevated serum bilirubin
* presence of pigment carotene
* markedly increased protein concentrations
* melanoma pigment
44
T/F:
Xanthochromia that is caused by bilirubin due to immature liver function is also commonly seen in infants, particularly premature infants
TRUE
45
appearance of a normal CSF
crystal clear
46
causes of grossly bloody CSF
* intracranial hemorrhage
| * due to puncture of a blood vessel during spinal tap procedure
47
visual examinations of CSF that would determine whether the blood is the result of hemorrhage or a traumatic tap
* uneven blood distribution
* clot formation
* xanthochromic supernatant
48
Blood from a cerebral hemorrhage will be (evenly/unevenly) distributed throughout the three CSF specimen tubes
evenly
: traumatic tap will leave the heaviest concentration of blood in tube 1, and gradually diminishing amounts in tubes 2 and 3.
49
T/F:
Fluid collected from a traumatic tap may form clots owing to the introduction of plasma fibrinogen into the specimen.
TRUE
: Bloody CSF caused by intracranial hemorrhage does not contain enough fibrinogen to clot
50
presence of web-like pellicle in CSF is associated with?
tubercular meningitis
: pellicles can be seen after overnight refrigeration of fluid
51
RBCs must usually remain in the CSF for approx. how many hours before noticeable hemolysis begins?
2 hours
52
T/F:
A xanthochromic supernatant would be the result of blood that has
been present longer than that introduced by the traumatic tap.
TRUE
: care should be taken; a recent hemorrhage would produce a clear supernatant, and introduction of serum protein from a traumatic tap could also cause the fluid to appear xanthochromic.
53
color of CSF (supernatant) from a recent hemorrhage
clear
54
how to examine a blood fluid for the presence of xanthrochromia?
centrifuge in a microhematocrit tube
examine against a white background
55
Other tests used for differentiation of blood CSF from intracranial hemorrhage or traumatic tap?
Microscopic Examination
: presence of ingested RBCs (erythrophagocytosis) or hemosiderin granules = intracranial hemorrhage
D-dimer Test
: detection of fibrin degradation product D-dimer by latex agglutination immunoassay indicates fibrin formation at a hemorrhage site
56
Cell count routinely performed on CSF specimens
leukocyte (WBC) count
57
In CSF analysis, cell count must be performed immediately. WBCs (particularly granulocytes and RBCs begin to lyse within ______, and leukocytes disintegrate after ____ hours.
1 hr; 2 hours
58
What percentage of leukocytes in the CSF begin to disintegrate after 2 hours?
40%
59
T/F:
Specimens that cannot be
analyzed immediately should be frozen.
FALSE
: refrigerated
60
Normal WBC count in normal adult CSF
0-5 WBCs/uL
61
T/F:
The number of leukocytes is higher in children as compared to adults
TRUE
:as many as 30 mononuclear cells/µL can be considered normal in newborns.
62
T/F:
Specimens that contain up to 200 WBCs or 400 RBCs/uL may appear clear
TRUE
: so it is necessary to examine all specimens microscopically
63
this is routinely used for performing CSF cell counts
Improved Neubauer Counting Chamber
64
This have not been used for performing CSF cell counts due to high background counts and poor reproducibility of low counts
Electronic cell counters
65
T/F:
The standard Neubauer calculation formula used for blood cell counts is also applied to CSF cell counts to determine the number of cells per microliter
TRUE
66
CSF Cell Count Formula
[(# of cells counted x dilution) / (# of cells counted x volume of 1 square)] = cells/uL
67
The CSF cell count formula can be used for both diluted and undiluted specimens
TRUE
: it also offers flexibility in the number and size of the squares counted
68
T/F:
| Clear specimens may be counted undiluted, provided no overlapping of cells is seen during the microscopic examinatio
TRUE
69
Dilutions for total cell counts are made with _________
normal saline
:then, mixed by inversion, and loaded into the hemocytometer with a Pasteur pipette
70
What parts of the hemocytometer are cells counted for CSF analysis?
4 corner squares and center square on both sides of the hemocytometer
71
T/F:
Lysis of RBCs must be obtained before performing the WBC count on either diluted or undiluted specimens.
TRUE
72
reagent used to lyse RBCs
3% glacial acetic acid
73
reagent used to stain WBCs
methylene blue
: added to the diluting fluid
: this provides better differentiation between neutrophils and mononuclear cells
74
how often must diluents be checked for contamination?
biweekly
75
Diluents are checked for contamination by examining them in a counting chamber under what magnification?
400x
76
T/F:
Contaminated diluents should be discarded and
new solutions must be prepared
TRUE
77
Speed of cytocentrifuge must be checked ______ (how often?)
monthly
78
used to check speed of cytocentrifuge
tachometer
: timing is checked with a stopwatch
79
If nondisposable counting chambers are used for CSF cell count, they must be soaked in a bactericidal solution for how long?
at least 15 minutes
: then thoroughly rinsed with water and cleaned with isopropyl alcohol after each use
80
Differential count on a CSF specimen is performed:
(a) on a stained smear
(b) via counting chamber
a. on a stained smear
81
T/F:
In differential counting on a CSF specimen, to ensure that the maximum number of cells is available for examination, the specimen should be concentrated before
preparing the smear.
TRUE
82
Methods available for specimen concentration
| prior to differential counting on CSF specimens
* sedimentation
* filtration
* centrifugation
* cytocentrifugation
83
Specimen concentration method/s that are not routinely used in the clinical laboratory but produce/s less cellular distortion
sedimentation
| filtration
84
This is a specimen concentration method performed when there is no cytocentrifuge available
centrifugation
85
In concentrating CSF specimens via centrifugation, how long must be the specimen centrifuged?
5-10 minutes
: supernatant fluid is removed and saved for additional tests
: slides made from suspended sediment are allowed to air dry
:stain slides with Wright's stain
86
In performing CSF cell count, if the cell count is low and finding 100 cells is not possible, what must be the manner of reporting?
report only the numbers of the cell types seen
87
In cytocentrifugation, how much CSF is used to combine with 1 drop of 30% albumin?
0.1 mL
:already produces adequate cell yield when processed with the cytocentrifuge
88
The purpose of adding albumin in cytocentrifugation
increases cell yield and decreases cellular distortion frequently seen on cytocentrifuged specimen
