CHAPTER 10: CSF Flashcards
1
Q
What are the three layers of meninges?
A
dura mater (hard mother), arachnoid (spiderweb-like), pia mater (gentle mother)
2
Q
What is the normal volume of CSF in adults?
A
90 to 150 mL
2
Q
CFS is produced by the?
A
Choroid plexuses of the two lumbar ventricles and the third and fourth ventricles
3
Q
It reabsorbs the circulating fluid back into the blood capillaries at a rate equal to its production
A
arachnoid granulations/villae
3
Q
In adults, approximately ______ of fluid is produced every hour
A
20 mL
3
Q
What is the normal volume of CSF in neonates?
A
10 to 60 mL
4
Q
These are capillary networks that form the CSF from plasma by mechanisms of selective filtration under hydrostatic pressure and active transport secretion
A
choroid plexuses
5
Q
They act as one-way valves that respond to pressure within the central nervous system (CNS) and prevent reflux of the fluid
A
Cells of the arachnoid granulations
6
Q
This is a very tight-fitting junctures that prevent the passage of many molecules
A
blood–brain barrier
6
Q
CSF is routinely collected by lumbar puncture between the?
A
third, fourth, or fifth lumbar vertebra
7
Q
This tube is used for chemical and serologic tests because these tests are least affected by blood or bacteria introduced as a result of the tap procedure
A
Tube 1
8
Q
This tube is usually designated for the microbiology Laboratory
A
Tube 2
9
Q
This tube is used for the cell count because it is the least likely to contain cells introduced by the spinal tap procedure
A
Tube 3
10
Q
A fourth tube may be drawn for the _____________ to better exclude skin contamination or for additional ____________.
A
microbiology laboratory & serologic tests, respectively
11
Q
It can be the result of an increased protein or lipid concentration, but also be indicative of infection
A
Cloudy, turbid, or milky specimen
12
Q
If it is not possible to perform tests STAT, the CSF specimen for hematology must be?
A
refrigerated up to 4 hours
12
Q
If it is not possible to perform tests STAT, the CSF specimen for microbiology must be?
A
remained at room temperature
13
Q
If it is not possible to perform tests STAT, the CSF specimen for chemistry and serology must be?
A
frozen
14
Q
A xanthochromic color due to the conversion of oxyhemoglobin to unconjugated bilirubin
A
Yellow
15
Q
The most common cause of xanthochromia is?
A
Presence of RBC degradation products
15
Q
It is not unusual for cell counts requested to be performed on both ______ and ______ to check for cellular contamination by the puncture
A
Tubes 1; Tube 4
15
Q
This can be an indication of intracranial hemorrhage, but it may also be due to the puncture of a blood vessel during the spinal tap procedure
A
Grossly bloody CSF
15
Q
A xanthochromic color due to heavy hemolysis
A
Orange
15
Q
A xanthochromic color due to a very slight amount of oxyhemoglobin
A
Pink
15
Cells must be counted within _____________ when the specimen is maintained at room temperature.
1 hour of collection
15
It is a term used to describe CSF supernatant that is pink, orange, or yellow.
Xanthochromia
15
If only one tube can be collected, it must be tested first in?
microbiology
15
Other causes of xanthochromia aside from RBC degradation include:
- Elevated serum bilirubin
- Presence of the pigment
carotene
- Increased protein concentrations
- Melanoma pigment
- Bilirubin due to immature liver function
16
T/F: It is not unusual for cell counts requested to be performed on both Tubes 1 and 4 to check for cellular contamination by the puncture
TRUE
16
The most common factor that causes xanthochromia
presence of red blood cell (RBC) degradation products
17
Examination of the fluid occurs first at the _______ and also is included in the _________
bedside; laboratory report
17
Xanthochromia that is caused by bilirubin due to immature liver function also is seen commonly in?
infants, *particularly premature infants*
17
The appearance of the CSF is crystal clear what is its **major significance**?
Normal
17
The appearance of the CSF is hazy, turbid, milky, and cloudy what is its possible **cause** and **major significance**?
Cause: WBCs
Major Significance: Meningitis
Cause: Microorganisms
Major Significance: Meningitis
Cause: Protein
Major Significance: (1) Disorders affecting blood-brain barrier
(2) Production of IgG within the CNS
18
The appearance of the CSF is oily what is its possible **cause**?
Cause: Radiographic contrast media
19
The appearance of the CSF is bloody what is its possible **cause** and **major significance**?
Cause: RBCs
Major Significance: Hemorrhage, Traumatic tap
19
The appearance of the CSF is xanthochromic what are its possible **causes** and **major significance**? (cite at least two)
Cause: Hemoglobin
Major Significance: Old hemorrhage, Lysed cells from traumatic tap
Cause: Bilirubin
Major Significance: RBC degradation, Elevated serum
bilirubin level
Cause: Carotene
Major Significance: Increased serum levels
Cause: Protein
Major Significance: Disorders affecting blood-brain barrier
Cause: Melanin
Major Significance: Meningeal
melanosarcoma
20
The appearance of the CSF is clotted what are its possible **causes** and **major significance**? (cite at least one)
Cause: Protein
Major Significance: Disorders affecting blood–brain barrier
Cause: Clotting factors
Major Significance: Introduced by traumatic tap
21
The appearance of the CSF is pellicle what are its possible **causes** and **major significance**?
Cause: Protein
Major Significance: Disorders affecting blood–brain barrier
Cause: Clotting factors
Major Significance: Tubercular
meningitis
22
Blood from a _______________ will be distributed evenly throughout the three CSF specimen tubes, whereas a _____________ will leave the heaviest concentration of blood in tube 1, with amounts gradually diminishing in tubes 2 and 3.
cerebral hemorrhage; traumatic tap
23
Fluid collected from a traumatic tap may form clots due to the introduction of ____________ into the specimen
plasma fibrinogen
23
Bloody CSF caused by __________ does not contain enough fibrinogen to clot
intracranial hemorrhage
24
What are the conditions that cause damage to the blood-brain barrier and also cause clot formation but usually do not produce a bloody fluid
meningitis, Froin syndrome, and blocked CSF circulation through the subarachnoid space.
25
This is associated with tubercular meningitis and can be seen after overnight refrigeration of the fluid
classic web-like pellicle
25
Usually RBCs must remain in the CSF for approximately _______ before noticeable hemolysis begins
2 hours
26
To examine a bloody fluid for the presence of xanthochromia, the fluid should be _______ in a microhematocrit tube and the supernatant examined against a white background
centrifuged
27
The microscopic findings of macrophages containing ingested RBCs (erythrophagocytosis) or hemosiderin granules indicates
Intracranial hemorrhage
27
Detection of the fibrin degradation product D-dimer by latex agglutination immunoassay indicates __________ at a hemorrhage site
fibrin formation
28
Normally _____ are not present in CSF
RBCs
28
Any cell count should be performed immediately because ______ and _____ begin to lyse within 1 hour, and 40% of the _______ disintegrate after 2 hours.
WBCs (particularly granulocytes); RBCs; leukocytes
29
Specimens that cannot be analyzed immediately should be ________
refrigerated up to 4 hours.
30
How many WBCs in CSF does a normal adult
0 to 5 WBCs/µL
30
The number (WBCs in CSF) is higher in ________, and as many as 30 mononuclear cells/µL can be considered normal in _________
children; newborns
31
Used routinely for performing CSF cell counts
Neubauer counting chamber
32
This increases precision, standardization, and faster turnaround time for results
Automation
32
Traditionally, _____________ have not been used for performing CSF cell counts because of the instrument’s high background counts and poor reproducibility of low counts
Electronic cell counters
33
This may be counted undiluted, provided no overlapping of cells is seen during the microscopic examination
Clear specimens
33
This provides better differentiation between neutrophils and mononuclear cells
Adding methylene blue to the diluting fluid stains the WBCs
33
The standard Neubauer calculation formula:
Number of cells counted × dilution/ Number of cells counted × volume of 1 square = cells/µL
33
This must be obtained before performing the WBC count on either diluted or undiluted specimens
Lysis of RBCs
34
Cells are counted in the _________ squares and the ______ square on both sides of the hemocytometer
four corner; center
35
If nondisposable counting chambers are used, they must be soaked in a bactericidal solution for at least ________ and then rinsed thoroughly with water and cleaned with ______________ after each use.
15 minutes; isopropyl alcohol
36
Methods available for specimen concentration include
- sedimentation
- filtration
- centrifugation
- cytocentrifugation
37
These methods are not used routinely in the clinical laboratory, although they do produce less cellular distortion
Sedimentation and filtration
38
When the differential count is performed, how many cells should be counted, classified, and reported in terms of percentage
100 cells
39
If the cell count is low and finding 100 cells is not possible, how do you report it?
report only the numbers of the cell types seen.
39
The cells found in normal CSF are primarily?
lymphocytes and monocytes
39
Adults usually have a predominance of?
lymphocytes to monocytes (70:30)
*Whereas the ratio is essentially reversed in children*
40
A high CSF WBC count of which the majority of the cells are neutrophils is considered indicative of?
bacterial meningitis
41
A CSF WBC count with a high percentage of lymphocytes and monocytes that is moderately elevated suggests meningitis of?
viral, tubercular, fungal, or parasitic origin.
41
In addition to bacterial meningitis, increased neutrophils are seen in the early stages (1 to 2 days) of?
viral, fungal, tubercular,
and parasitic meningitis
42
These are common in cases of viral, tubercular, and fungal meningitis
A mixture of lymphocytes and monocytes
43
CSF is centrifuged for how many minutes?
5-10 minutes
44
Stain used for CSF
Wright's stain
45
These are lost more rapidly in CSF
Granules
46
Neutrophils associated with bacterial meningitis may contain?
phagocytized bacteria
47
Neutrophils with pyknotic nuclei indicate?
degenerating cells
48
Seen as a result of contamination from bone marrow during the spinal tap and is found in approximately 1% of specimens
Nucleated red blood cells (NRBCs)
48
Capillary structures and endothelial cells may be seen after a?
traumatic tap
49
A moderately elevated WBC count (less than 50 WBCs/µL) with increased normal and reactive lymphocytes and plasma cells may indicate?
multiple sclerosis or other degenerative neurological disorders
50
An increase of these is seen in the CSF in association with parasitic infections, fungal infections (primarily ***Coccidioides immitis***), and introduction of foreign material, including medications and shunts, into the CNS
Eosinophils
51
Seen in cases of both asymptomatic HIV infection and AIDS.
Increased lymphocytes
52
Its purpose in the CSF is to remove cellular debris and foreign objects, such as RBCs
Macrophages
52
Macrophages appear within how many hours after RBCs enter the CSF?
within 2 to 4 hours
*Macrophages are also frequently seen after repeated taps*
52
The finding of increased macrophages indicates?
previous hemorrhage
53
Further degradation of the phagocytized RBCs results in the appearance of?
dark blue or black iron-containing hemosiderin granules
54
Represent further degeneration. They are iron-free, consisting of hemoglobin and unconjugated bilirubin
Yellow hematoidin crystals
54
These are seen most frequently after diagnostic procedures, such as pneumoencephalography, and in fluid obtained from ventricular taps or during neurosurgery
Nonpathologically significant cells
55
These are from the epithelial lining of the choroid plexus. They are seen singularly and in clumps.
Usually nucleoli are absent, and nuclei have a uniform appearance
Choroidal cells
56
These are from the lining of the ventricles and neural canal.
They have less defined cell membranes and frequently are seen in clusters.
Ependymal cells
57
Represent lining cells from the arachnoid. Usually they are seen in clusters and may be seen with systemic malignancies
Spindle-shaped cells
58
These cells in the CSF are seen frequently as a serious complication of acute leukemias. Often nucleoli are more prominent than in blood smears
Lymphoblasts, myeloblasts, and monoblasts
59
These are seen in the CSF also and indicate dissemination from the lymphoid tissue.
They resemble large and small lymphocytes and usually appear in clusters of large, small, or mixed cells. Nuclei may appear cleaved, and prominent nucleoli are present
Lymphoma cells
60
Primarily from malignancies in the lung, breast, renal system, and gastrointestinal system
Metastatic carcinoma cells *of nonhematologic origin*
61
Cells from primary CNS tumors include:
astrocytomas, retinoblastomas, and medulloblastomas
62
The chemical test performed most frequently on CSF is?
Protein determination
63
T/F: Normal CSF contains a very huge amount of protein
FALSE. *It contains a **very smal**l amount of protein*
63
Reference values for total CSF protein usually are
15 to 45 mg/dL
*higher values are found in infants and people over age 40*
64
This makes up most of the CSF protein
Albumin
65
The second most prevalent protein fraction in CSF
transthyretin (previously called prealbumin)
66
The major beta globulin present
Transferrin
67
A carbohydrate-deficient transferrin fraction seen in CSF but not in serum
"tau"
68
The primary CSF gamma globulin
Immunoglobulin G (IgG)
*with only a small amount of immunoglobulin A (IgA) and Immunoglobulin M (IgM)*
69
IgG index formula:
IgG index = CSF IgG (mg/dL)/serum IgG (g/dL) /
CSF albumin (mg/dL)/serum albumin (g/dL)
69
These proteins are not found in normal CSF
Fibrinogen and beta lipoprotein
69
This method has been adapted to automated instrumentation in the form of nephelometry
turbidity method
70
Clinical Causes of Elevated CSF Protein:
- Meningitis
- Hemorrhage
- Primary CNS tumors
- Multiple sclerosis
- Guillain-Barré syndrome
- Neurosyphilis
- Polyneuritis
- Myxedema
- Cushing disease
- Connective tissue disease
- Polyneuritis
- Diabetes
- Uremia
70
The two techniques used most routinely for measuring total
CSF protein:
the principles of turbidity production and dye-binding ability
70
Clinical Causes of Decreased CSF Protein:
- CSF leakage/trauma
- Recent puncture
- Rapid CSF production
- Water intoxication
71
CSF/serum albumin index formula:
CSF/serum albumin index = CSF albumin (mg/dL) / Serum albumin (g/dL)
71
This is used as a comparison for CSF/serum albumin index
IgG index
72
These stimulate the immunocompetent cells in the CNS to show a higher proportion of IgG
Diseases, including multiple sclerosis
73
CSF/serum albumin index value that represents an intact blood–brain barrier
9
74
IgG index value that indicates IgG production within the CNS
values greater than 0.70
74
Used to detect oligoclonal bands, which represent inflammation within the CNS
CSF protein electrophoresis
75
Serum banding that appears in the CSF as a result of leakage at the blood-brain barrier or traumatic introduction of blood into the CSF specimen is caused by?
Disorders, such as leukemia, lymphoma, and viral infection
76
The presence of two or more oligoclonal bands in the CSF that are not present in the serum can be a valuable tool in diagnosing?
Multiple sclerosis
76
Oligoclonal banding remains positive during remission of ________ but disappears in other disorders.
multiple sclerosis
76
Serological testing of the CSF is
performed to detect the presence of?
neurosyphilis
76
Banding representing both systemic and neurological involvement is seen in the serum and CSF with?
HIV infection
77
This is not recommended to diagnose neurosyphilis because it is less sensitive than the VDRL
rapid plasma reagin (RPR) test
77
The procedure recommended by
the CDC to diagnose neurosyphilis
Venereal Disease Research Laboratory (VDRL)
78
The use of this antibiotic in the early stages of syphilis has greatly reduced the number of neurosyphilis case
Penicillin
79
If the FTA-ABS is used, care must be taken to prevent contamination with blood because?
FTA-ABS remains positive in the serum of treated cases of syphilis
80
A specific method for detecting bacteria in CSF, but lacks sensitivity
Gram staining
81
RBCs contain high concentrations of lactate, and results that are falsely elevated may be obtained on?
xanthochromic or hemolyzed fluid
81
Can detect the cause of meninigitis with a small amount of the pathogen’s DNA
Nucleic acid amplification tests
82
Provide a rapid method for detecting C. neoformans with a high sensitivity and specificity
lateral flow assay (LFA)
82
Based on the amplification of regions of ribosomal RNA (rRNA) genes to detect and differentiate causative pathogens of meningitis
PCR assays
82
Provide a rapid means for detecting and identifying microorganisms in CSF.
Latex agglutination and enzyme-linked immunosorbent
assay (ELISA)
83
Detect the presence of C. neoformans antigen in serum and CSF provide a more sensitive method than the India ink preparation
Latex agglutination tests
83
Performed routinely on CSF from all suspected cases of meningitis, although its value lies in detecting bacterial and fungal organisms
Gram stain
84
Does not appear to be as sensitive to N. meningitidis as it is to the other organisms
bacterial antigen test (BAT)
85
The normal concentration of glutamine in the CSF is?
8 to 18 mg/dL
85
Reference CSF glucose
approximately 65 mg/dL
86
Its presence indicates recent destruction of the myelin sheath that protects the axons of the neurons (demyelination)
Myelin Basic Protein (MBP)
87
The course of multiple sclerosis can be monitored by measuring the amount of?
Myelin Basic Protein (MBP)
88
Valuable aid in diagnosing and managing meningitis cases
CSF Lactate
89
Levels greater than _______ are seen frequently with bacterial meningitis, whereas in viral meningitis, lactate levels remain lower than _______
35 mg/dL; 25 mg/dL
89
This is not limited to meningitis and can also result from any condition that decreases oxygen flow to the tissues
Elevated CSF lactate
