CEREBROSPINAL FLUID Flashcards
1
Q
What are the main functions of CSF?
A
- provides nutrients to nervous tissue
- removes metabolic wastes
- produces mechanical barrier to cushion the brain and spinal cord against trauma
2
Q
This lines the brain and the spinal cord
A
Meninges
3
Q
Three layers of the meninges
A
Dura mater
Arachnoid
Pia mater
4
Q
This outermost layer of the meninges lines the skull and vertebral canal
A
Dura mater
5
Q
Pertained to as the “hard mother”
A
Dura mater
6
Q
This meningeal layer is a filamentous (spider-like) inner membrane.
A
Arachnoid
7
Q
The innermost layer of the meninges lines the surfaces of the brain and spinal cord
A
Pia mater
8
Q
This is where CSF is produced
A
Choroid plexuses of the two lumbar ventricles and the third and fourth ventricles
9
Q
Which layer of the meninges is referred to as the “gentle mother”
A
Pia mater
10
Q
In adults, approximately how many mL of CSF is produced every hour?
A
20 mL
11
Q
This is a space located between the arachnoid and pia mater where the CSF flows through
A
Subarachnoid space
12
Q
Normal volume of CSF in adults (range)
A
90-150 mL
13
Q
Normal volume of CSF in neonates (range)
A
10-60 mL
14
Q
How is the 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.
15
Q
The cells of the arachnoid granulations act as (one-way/two-way) valves that respond to pressure within the central nervous system (CNS) and prevent reflux of the fluid
A
One-way
16
Q
TRUE or FALSE:
The chemical composition of the CSF does not resemble an ultrafiltrate of plasma.
A
TRUE
17
Q
The choroid plexuses are capillary networks that form the CSF from plasma by mechanisms of ________ under hydrostatic pressure and active transport secretion.
A
Selective filtration
18
Q
These are cells that line the capillary walls throughout the body.
A
Endothelial cells
NOTE:
Endothelial cells in the capillary walls are loosely connected to allow passage of soluble nutrients and wastes between the plasma and the tissues.
19
Q
The tight-fitting structure of endothelial cells in the choroid plexuses is called:
A
Blood-brain barrier (BBB)
20
Q
TRUE or FALSE:
Diseases such as meningitis and multiple sclerosis disrupt BBB
A
TRUE
Note:
This allows leukocytes, proteins, and additional chemicals to enter CSF
21
Q
This is the procedure done to collect CSF
A
Lumbar puncture
22
Q
Where is lumbar puncture done?
A
Between the third, fourth, or fifth lumbar vertebra
23
Q
TRUE or FALSE:
Lumbar puncture is considered a complicated procedure.
A
FALSE
NOTE:
* Lumbar puncture is not complicated but may require certain precautions.
- It requires measurement of intracranial pressure and technique to prevent infection or neural tissue damage
24
Q
How many tubes are required for CSF collection?
A
Three (3)
25
In CSF collection, Tube 1 is for:
Chemical and serologic tests
NOTE:
These tests are least affected by blood or bacteria introduced as a result of the tap procedure.
26
In CSF collection, Tube 2 is for:
Microbiology
27
In CSF collection, Tube 3 is for:
Cell count
NOTE:
Tube 3 is the least likely to contain cells introduced by the spinal tap procedure.
28
In CSF collection, a fourth tube may be filled. This will be for what test/s?
* Microbiology (to better exclude skin contamination)
* Additional serologic tests
29
TRUE or FALSE:
Excess CSF fluid drawn may be discarded.
FALSE
NOTE:
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
At what temperature must excess CSF fluid be stored?
A. Room temp
B. Refrigerated
C. Frozen
C. Frozen
32
TRUE or FALSE:
CSF testing is ideally performed on a STAT basis.
TRUE
33
Storage condition of hematology tubes?
Refrigerated
34
Storage condition of microbiology tubes?
Room temperature
35
Storage condition of chemistry and serology tubes?
Frozen
36
If only one tube can be filled with CSF, what test must go first?
Microbiology
37
What tubes can be used to perform cell counts to check for cellular contamination by puncture?
Tubes 1 & 4
38
Appearance of normal CSF
Crystal-clear
39
CSF appearance that may be a result of an increased protein or lipid concentration, but may also be indicative of infection
Cloudy/Turbid/Milky
NOTE:
The cloudiness is mainly caused by the presence of WBCs
40
Term used when CSF supernatant is pink, orange, or yellow.
Xanthochromia
41
Most common cause of xanthochromia
Presence of RBC degradation products
42
CSF color that would indicate that there is a very slight amount of oxyhemoglobin
Pink
43
CSF color that would indicate heavy hemolysis
Orange
44
CSF color that would indicate conversion of oxyhemoglobin to unconjugated bilirubin
Yellow
45
Other causes of xanthochromia aside from presence of RBC degradation products:
* Elevated serum bilirubin
* Presence of pigment carotene
* Markedly increased protein concentrations
* Melanoma pigment
46
TRUE or FALSE:
Xanthochromia that is caused by bilirubin due to immature liver function is also commonly seen in infants, particularly premature infants.
TRUE
47
Oily appearance of CSF may be caused by:
Radiographic contrast media
48
Causes of grossly bloody CSF
* Intracranial hemorrhage
* Puncture of a blood vessel during spinal tap procedure
49
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
50
Blood from a cerebral hemorrhage will be (evenly/unevenly) distributed throughout the three CSF specimen tubes.
Evenly
NOTE:
Traumatic tap will leave the heaviest concentration of blood in tube 1, and gradually diminishing amounts in tubes 2 and 3.
51
TRUE or FALSE:
Fluid collected from a traumatic tap may form clots owing to the introduction of plasma fibrinogen into the specimen.
TRUE
NOTE:
Bloody CSF caused by intracranial hemorrhage does not contain enough fibrinogen to clot.
Diseases that damage the BBB also cause clot formation but do not usually produce a bloody fluid.
52
A classic web-like pellicles is associated with what disease?
Tubercular meningitis
NOTE:
Pellicles can be seen after overnight refrigeration of the fluid
53
RBCs must usually remain in the CSF for approximately ____ hours before noticeable hemolysis begins.
2 hours
NOTE:
A xanthochromic supernatant would be the result of blood that has been present longer than that introduced by the traumatic tap.
54
A recent hemorrhage would produce what appearance of CSF supernatant
Clear
55
How to examine a bloody fluid for the presence of xanthochromia?
Fluid is centrifuged in a microhematocrit tube and the supernatant is examined against a white background
56
Additional tests used to differentiate bloody CSF due to intracranial hemorrhage from bloody CSF due to 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
57
Type of cell count routinely performed on CSF specimens
Leukocyte (WBC) count
58
In CSF analysis, cell count must be performed immediately. WBCs (particularly granulocytes) and RBCs begin to lyse within ______, and leukocytes disintegrate after ____ hours.
1 hour; 2 hours
59
What percentage of leukocytes in the CSF begin to disintegrate after 2 hours?
40%
60
TRUE or FALSE:
Specimens that cannot be analyzed immediately should be frozen.
FALSE
NOTE:
Only refrigerated
61
Normal WBC count in normal adult CSF
0-5 WBCs/uL
62
TRUE or FALSE:
The number of leukocytes present in children is higher as compared to that of adults
TRUE
NOTE:
30 mononuclear cells/uL is still considered normal in newborns
63
TRUE or FALSE:
Specimens that contain up to 200 WBCs or 400 RBCs/uL may still appear clear
TRUE
NOTE:
This is why microscopic examination of specimens is necessary
64
This is routinely used in performing CSF cell counts
Improved Neubauer Counting Chamber
65
This tool has not been used in performing CSF cell counts due to high background counts and poor reproducibility of low counts.
Electronic cell counters
66
TRUE or FALSE:
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
67
CSF Cell Count Formula
(# of cells counted x dilution) / (# of cells counted x volume of 1 square) = cells/uL
68
TRUE or FALSE:
The CSF cell count formula may be used for both diluted and undiluted specimens
TRUE
NOTE:
The formula also offers flexibility in the number and size of the squares counted.
69
TRUE or FALSE:
Clear specimens may be counted undiluted, provided no overlapping of cells is seen during the microscopic examination.
TRUE
70
This is used to dilute total cell counts
Normal saline
NOTE:
After the addition of normal saline, the sample is mixed by inversion, and loaded into the hemocytometer with a Pasteur pipette.
71
What parts of the hemocytometer are cells counted for CSF analysis?
4 corner squares and center square on both sides of the hemocytometer
72
TRUE or FALSE:
Lysis of RBCs must be obtained before performing the WBC count on either diluted or undiluted specimens.
TRUE
73
This is the reagent used to lyse RBCs prior to WBC count
3% glacial acetic acid
74
This is used to stain white blood cells to provide better differentiation between neutrophils and mononuclear cells.
Methylene blue
75
How often must diluents used in CSF analysis be checked for contamination?
Biweekly
76
Diluents used in CSF analysis are checked for contamination by examining them in a counting chamber under what magnification?
400x
77
How often must the cytocentrifuge be checked?
Monthly
78
This is used to check the speed of the cytocentrifuge
Tachometer + Timer
79
If non disposable counting chambers are used for CSF cell count, they must be soaked in a bactericidal solution for how long?
At least 15 minutes
NOTE:
After this, they must be 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
NOTE:
There is poor visualization of cells in the counting chamber which can cause overlooking of abnormal cells
81
TRUE or FALSE:
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 used for specimen concentration (CSF)
* 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 and 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
86
How many cells must be counted in performing differential count?
100
87
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
88
In cytocentrifugation, what volume of CSF is used to combine with 1 drop of 30% albumin to produce adequate cell yield?
0.1 mL
89
What is the purpose of adding albumin in the process of cytocentrifugation?
increases cell yield and decreases cellular distortion frequently seen on cytocentrifuged specimen
90
In cytocentrifugation, a daily control slide for bacteria is prepared using what reagents?
0.2 mL saline
Two drops of 30% albumin
91
Primary cells found in normal CSF
Lymphocytes
Monocytes
92
Ratio of lymphocytes to monocytes in adult CSF
70:30
NOTE:
Ratio is reversed in children.
93
Term used to describe an increased cell count (white blood cells) in body fluids such as CSF
Pleocytosis
94
TRUE or FALSE:
Pleocytosis is normal.
FALSE
95
A high CSF WBC count with primarily neutrophils is indicative of what condition/s?
Bacterial meningitis
96
A moderately elevated CSF WBC count with a high percentage of lymphocytes and monocytes is indicative of what condition/s?
Viral meningitis
Tubercular meningitis
Fungal meningitis
Parasitic meningitis
97
Major clinical significance when the predominant cells seen in CSF are LYMPHOCYTES.
* Normal
* Viral, tubercular, fungal meningitis
* Multiple sclerosis
98
Major clinical significance when the predominant cells seen in CSF are NEUTROPHILS.
* Bacterial meningitis
* Early cases of viral, tubercular, and fungal meningitis
* Cerebral hemorrhage
99
Major clinical significance when the predominant cells seen in CSF are MONOCYTES.
* Normal
* Viral, tubercular, fungal meningitis
* Multiple sclerosis
100
Major clinical significance when the predominant cells seen in CSF are MACROPHAGES.
* RBCs present in spinal fluid
NOTE:
Macrophages may contain phagocytized RBCs appearing as empty vacuoles or ghost cells, hemosiderin granules, and hematoidin crystals.
101
Major clinical significance when the predominant cells seen in CSF are BLAST FORMS.
Acute leukemia
102
Major clinical significance when the predominant cells seen in CSF are LYMPHOMA CELLS.
Disseminated lymphomas
103
Major clinical significance when the predominant cells seen in CSF are PLASMA CELLS.
* Multiple sclerosis
* Lymphocyte reactions
104
Major clinical significance when the predominant cells seen in CSF are EPENDYMAL, CHOROIDAL, AND SPINDLE-SHAPED CELLS.
Diagnostic procedures
105
Major clinical significance when the predominant cells seen in CSF are MALIGNANT CELLS.
* Metastatic carcinomas
* Primary central nervous system carcinoma
106
TRUE or FALSE:
Aside from bacterial meningitis, neutrophils may also be seen in CSF in early stages of viral, fungal, tubercular, and parasitic meningitis.
TRUE
107
Appearance of neutrophils that indicate degenerating cells
Presence of pyknotic nuclei
NOTE:
They resemble nucleated red blood cells but usually have multiple nuclei
108
A moderately elevated WBC count equates to how many WBCs/uL?
Less than 50
109
Increased number of eosinophils in the CSF is linked to fungal infections, specifically?
Coccidoides immitis
110
Purpose of macrophages in the CSF
to remove cellular debris and foreign objects such as RBCs
111
Macrophages appear after how many hours after RBCs enter the CSF?
2-4 hours
112
Degradation of phagocytized RBCs results in the appearance of dark blue or black iron-containing hemosiderin granules. What type of crystals indicate further degeneration?
Yellow hematoidin crystals
NOTE:
These are iron-free, consisting of hemoglobin and unconjugated bilirubin.
113
Appearance of these cells in the CSF are from the epithelial lining of the choroid plexus.
Choroidal cells
NOTE:
These may be seen singularly and in clumps.
114
Where did ependymal cells that are seen in the CSF come from?
From the lining of the ventricles and neural canal.
NOTE:
They have less defined cell membranes and are frequently seen in clusters. Nucleoli are also often present.
115
These are cells found in CSF that represent lining cells from the arachnoid. They may be seen in clusters and with systemic malignancies.
Spindle-shaped cells
116
Presence of these malignant cells in the CSF indicate serious complication of acute leukemias.
Lymphoblasts
Myeloblasts
Monoblasts
117
Presence of these cells in the CSF indicate dissemination from the lymphoid tissue
Lymphoma cells
118
Metastatic carcinoma cells of nonhematologic origin primarily come from malignancies of which organs?
Lungs
Breast
Kidney/Renal
GI tract
119
These are cells that come from primary CNS tumors
Astrocytomas
Retinoblastomas
Medulloblastomas
120
This is the most frequently performed chemical test on CSF.
Protein determination
121
TRUE or FALSE:
CSF may normally contain protein.
TRUE
NOTE:
Normal CSF contains small amount of protein.
122
Normal values of CSF protein:
15-45 mg/dL
NOTE:
This may be method dependent, and higher values may be present in infants and people >40 years old.
123
Major protein present in both serum and CSF.
Albumin
124
The second most prevalent fraction (protein) in CSF
Prealbumin
125
What are the primary alpha globulins present in the CSF
Haptoglobin
Ceruloplasmin
126
The major beta globulin present in CSF
Transferrin
127
This is a carbohydrate-deficient transferrin fraction that is seen in CSF but not in serum
Tau
128
The primary immunoglobulin found in CSF
IgG
129
The second primary immunoglobulin found in CSF
IgA (present in small amounts)
130
TRUE or FALSE:
IgM, fibrinogen, and beta lipoprotein may also be found in normal CSF.
Immunoglobulin M (IgM), fibrinogen, and beta lipoprotein are not found in
131
Most common causes of elevated CSF protein
Meningitis
Hemorrhage conditions damaging BBB
132
The most routinely used techniques for measuring total CSF protein utilize which top two mechanisms?
Turbidity production
Dye-binding ability
133
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Meningitis
ELEVATED
134
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Hemorrhage
ELEVATED
135
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Primary CNS tumors
ELEVATED
136
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Multiple sclerosis
ELEVATED
137
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Guillain-Barre syndrome
ELEVATED
138
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Neurosyphilis
ELEVATED
139
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Polyneuritis
ELEVATED
140
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Myxedema
ELEVATED
141
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Cushing disease
ELEVATED
142
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Connective tissue disease
ELEVATED
143
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Diabetes
ELEVATED
144
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Uremia
ELEVATED
145
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
CSF leakage
DECREASED
146
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Recent puncture
DECREASED
147
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Rapid CSF production
DECREASED
148
Indicate whether the following condition causes ELEVATED or DECREASED CSF protein.
Water intoxication
DECREASED
149
To accurately determine whether IgG is increased because it is being produced within the CNS or is elevated as the result of a defect in the BBB, comparisons between serum and CSF levels of what analytes are made?
Albumin
IgG
150
This method is done to evaluate the integrity of the blood-brain barrier.
CSF/serum albumin index
151
This method is done to measure IgG synthesis within the CNS
IgG index
152
In calculating CSF/serum albumin index, an index value of less than ___ represents an intact blood-brain barrier.
9
153
IgG index formula:
(CSF IgG/serum IgG) / (CSF albumin/serum albumin)
CSF IgG and CSF albumin: mg/dL
Serum IgG and serum albumin: mg/dL
154
In calculating IgG index, a value greater than ______ indicate IgG production within the CNS.
0.70
155
The primary purpose for performing CSF protein electrophoresis is to detect what?
Oligoclonal bands
NOTE:
This represents inflammation within the CNS.
156
Presence of this protein in the CSF indicates recent destruction of myelin sheath.
Myelin basic protein (MBP)
157
The process of destruction of myelin sheath.
Demyelination
158
CSF glucose approximates to what percentage of the plasma glucose?
60%-70%
159
In evaluating CSF glucose, the blood glucose must be drawn _____ hours before spinal tap.
About 2 hours
NOTE:
This is to allow time for equilibration between the blood and fluid.
160
A markedly decreased CSF glucose level with an increased WBC count (primarily neutrophils) are indicative of what condition?
Bacterial meningitis
161
A decreased CSF glucose with increased WBC count that are primarily lymphocytes is indicative of what condition?
Tubercular meningitis
162
Normal CSF glucose with increased number of lymphocytes is indicative of what condition?
Viral meningitis
163
CSF lactate levels of greater than 35 mg/dL is often observed in which type of meningitis?
Bacterial meningitis
164
CSF lactate levels of lower than 25 mg/dL is often observed in which type of meningitis?
Viral meningitis
165
TRUE or FALSE:
Tissue destruction within the CNS owing to oxygen deprivation (hypoxia) increases CSF lactic acid levels.
TRUE
166
Normal concentration of CSF glutamine
8-18 mg/dL
167
Glutamine is produced from a-ketoglutarate and ________.
Ammonia
168
TRUE or FALSE:
As the concentration of ammonia in the CSF increases, the supply of α-ketoglutarate becomes depleted.
TRUE
169
Normal values of CSF lactate
10-24 mg/dL
170
CSF lactate levels of _____ mg/dL is observed in patients with some disturbance of consciousness
>35 mg/dL
171
CSF culture may take (duration) in cases of bacterial meningitis and (duration) in cases of tubercular meningitis.
24 hours; 6 weeks
172
In conducting CSF culture, the CSF should first be centrifuged at _______ for ____ minutes
1500g; 15
173
Organisms most frequently encountered in a CSF culture:
Streptococcus pneumoniae
Haemophilus influenzae
Escherichia coli
Neisseria meningitidis
174
Organisms that may be encountered in CSF culture in newborns:
Streptococcus agalactiae
Listeria monocytogenes
175
This is a condition considered as a frequently occurring complication of AIDS and often requires an India ink preparation aside from gram staining of the CSF.
Cryptococcal meningitis (caused by Cryptococcus neoformans)
176
This is a pattern produced by Cryptococcus in gram-stained CSF specimens.
Starburst
177
This test is considered more sensitive in detecting the presence of C. neoformans antigen in serum and CSF than India ink preparation.
Latex agglutination tests
178
This is the most common cause of false-positive reactions in latex agglutination tests for CSF.
Rheumatoid factor (RF)
179
This method helps detect C. neoformans in CSF by utilizing a reagent strip coated with monoclonal antibodies that react with the cryptococcal polysaccharide capsule.
Lateral Flow Assay (LFA)
180
This is an opportunistic parasite capable of entering the nasal passages and migrating along the olfactory nerves to invade the brain. These are mainly found in small lakes and ponds and can be observed in a CSF wet preparation.
Naegleria fowleri
181
This is the procedure recommended by CDC to diagnose neurosyphilis.
Venereal Disease Research Laboratories (VDRL)
182
TRUE or FALSE:
Rapid plasma regain (RPR) test is less sensitive than the VDRL.
TRUE
NOTE:
Order of sensitivity of tests used to diagnose neurosyphilis:
FTA-ABS>VDRL>RPR
