Cerebrospinal Fluid Flashcards
1
Q
Functions of Cerebrospinal fluid
A
Supply nutrients to the nervous tissue
Remove metabolic wastes
Produce a mechanical barrier to cushion the brain and spinal cord against trauma
2
Q
The brain and spinal cord are lined by
A
Meninges
3
Q
3 layers of meninges
A
Dura mater
Arachnoid mater
Pia mater mater
4
Q
Outer layer that lines the skull and vertebral canal
A
Dura mater
5
Q
Dura mater is latin for
A
Hard mother
6
Q
Filamentous inner membrane
A
Arachnoid mater
7
Q
Appearance of arachnoid mater
A
Spiderweb-like
8
Q
Thin membrane lining the surfaces of the brain and spinal cord
A
Pia mater
9
Q
Pia mater is latin for
A
Gentle mother
10
Q
It is where CSF flows
A
Subarachnoid space
11
Q
Location of subarachnoid space
A
Between the arachnoid and pia mater
12
Q
CSF is produced in
A
Choroid plexuses of the two lumbar ventricles and the third and fourth ventricles
13
Q
Rate of CSF production in adults
A
20 mL/hour
14
Q
Normal volume of CSF for adult
A
90-150 mL
15
Q
Normal volume of CSF for neonates
A
10-60 mL
16
Q
CSF flows through the subarachnoid space and reabsorbed back into the blood capillaries in the arachnoid granulations/villae at a rate equal to its production. True or Fasle?
A
True
17
Q
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. True or False?
A
True
18
Q
Capillary networks that form the CSF from plasma by mechanisms of selective filtration under hydrostatic pressure and active transport secretion
A
Choroid plexuses
19
Q
The chemical composition of the CSF resemble an ultrafiltrate of plasma. True or False?
A
False; does not resemble
20
Q
Tight-fitting structure of the endothelial cells in the choroid plexuses that prevent the passage of many molecules
A
Blood-Brain Barrier (BBB)
21
Q
Functions of BBB
A
Protect the brain from chemicals and other substances circulating in the blood that could harm the brain tissue. Also prevent the passage of helpful substances including antibodies and medications
22
Q
Disruption of the blood–brain barrier by diseases results to
A
Leukocytes, proteins, and additional chemicals to enter the CSF
23
Q
CSF is routinely collected by
A
Lumbar puncture/tap
Cisternal puncture
24
Q
Location for lumbar puncture
A
Between the third, fourth, or fifth lumbar vertebra
25
Volume of CSF collected under normal pressure
20 mL
26
Volume of CSF collected if pressure is less than or greater than normal
1-2 mL
27
CSF is collected in how many tubes?
3
28
The use of 1st tube
Chemical and serologic tests
29
The use of 2nd tube
Microbiology
30
The use of 3rd tube
Hematology
31
A fourth tube may be drawn for
Microbiology
Serology
32
Order of testing for CSF
Micro → Hema → Chemistry/Serology
33
CSF tests are performed on a STAT basis. True or False?
True
34
How to maintain the specimen if STAT is not possible?
Hematology tubes are refrigerated
Microbiology tubes remain at room temperature
Chemistry and serology tubes are frozen
35
Normal appearance of CSF
Crystal-clear
36
Cloudy or turbid, milky indicates
Increase WBC that is >200 /µL
Increase RBC that is >400/µL
Increased protein or lipid concentration
Presence of infection (meningitis)
Disorders affecting the blood-brain barrier
37
Xanthochromic CSF indicates
Presence of RBC degradation products
38
Color of CSF if there is a very slight amount of oxyhemoglobin
Pink
39
Color of CSF if there is a heavy hemolysis
Orange
40
Color of CSF due to conversion of oxyhemoglobin to unconjugated bilirubin
Yellow
41
Color of CSF due to methemoglobin formation, hematoma, melanin
Brown
42
>6000 RBCs /µL in CSF indicates
Hemolysis
43
Nonpathologic cause of bloody CSF
Traumatic tap
44
Pathologic cause of bloody CSF
Intracranial hemorrhage / cerebral hemorrhage
45
Viscous CSF is caused by
Cryptococcal meningitis
Metastasizing mucin producing adenocarcinoma
46
Cause of oily CSF
Radiographic contrast dye
47
Cause of clotted CSF
Disorders affecting the blood-brain barrier
48
CSF with pellicle formation
Tubercular meningitis
49
Distribution of blood in case of intracranial hemorrhage
Even in all 3 tubes
50
Distribution of blood in case of traumatic tap
Uneven; tube 1 has the heaviest concentration of blood, and gradually diminishing amounts in Tubes 2 and 3
51
Difference between intracranial hemorrhage and traumatic tap in terms of clot formation
Absent in IH; present in TT
52
Difference between intracranial hemorrhage and traumatic tap in terms of xanthochromic supernatant
Common in IH; not common in TT
53
Difference between intracranial hemorrhage and traumatic tap in terms of erythrophagocytosis
Present in IH; absent in TT
54
Difference between intracranial hemorrhage and traumatic tap in terms of D-dimer test
Positive in IH; negative in TT
55
Most common or routinely performed test on CSF specimens
WBC count
56
How to calculate for CSF RBC count
Perform a total cell count and a WBC count and subtract the WBC count from the total count
57
WBCs (particularly granulocytes) and RBCs begin to lyse within
1 hour
58
Amount of leukocytes that disintegrate after 2 hours
40%
59
Specimens that cannot be analyzed immediately should be
Refrigerated
60
Normal WBC in CSF of adult
0-5 WBCs/µL
61
Normal WBC in CSF of newborn
0-30 mononuclear cells/µL
>35 cells/µL: normal (Brunzel)
62
Formula for CSF cell counts
cells/µL = (Number of cells counted x Dilution)/(Number of squares counted x Volume of 1 square)
63
Routinely used for performing CSF cell counts
Improved Neubauer counting chamber
64
Used to lyse RBCs
3% glacial acetic acid
65
Stain that provides better differentiation between neutrophils and mononuclear cells
Methylene blue
66
Done only in case of traumatic tap to correct Total Protein and WBC count
RBC count
67
Correction for Total Protein and WBC count
Subtract 1 WBC for every 700 RBCs seen
Subtract 8 mg/dL TOTAL PROTEIN for every 10,000 RBCs/µL seen
Subtract 1 mg/dL of TP for every 1,200 RBCs/µL seen
68
How often to check cytocentrifuge?
Monthly
69
Tool used to measure cytocentrifuge speed and timing
Tachometer and stopwatch
70
The CSF differential count should be performed on a
Stained smear
71
Specimen for CSF differential count should be
Concentrated
72
Concentrated specimen for CSF differential count is achieved thru
Sedimentation
Filtration
Centrifugation
Cytocentrifugation
73
Duration of CSF centrifugation
5-10 minutes
74
Stain used for differential CSF count
Wright's stain
75
Process where cells present in the fluid are forced into a monolayer within a 6 mm diameter circle on the slide
Cytocentrifugation
76
As little as 1 mL of CSF combined with one drop of 3.0% albumin produces an adequate cell yield when processed with the cytocentrifuge. True or False?
False; 0.1 mL CSF and 30% albumin
77
Primary WBC in CSF
Lymphocytes
Monocytes
78
Lymphocytes:Monocytes ratio in adults
70:30
79
Lymphocytes:Monocytes ratio in children
30:70
80
The presence of increased numbers of lymphocytes and monocytes
Pleocytosis
81
Pleocytosis is normal. True or False?
False; abnormal
82
CSF differential count is valuable in determining the type of microorganism causing meningitis. True or False?
True
83
Pleocytosis involving neutrophils
Bacterial meningitis
84
Pleocytosis involving lymphocytes and monocytes
Meningitis of viral, tubercular, fungal, or parasitic origin
85
Neutrophils with pyknotic nuclei indicate
Degenerating cells
86
NRBCs seen in CSF indicates
Bone marrow contamination during spinal tap
87
Type of lymphocytes frequently present during viral infections
Reactive lymphocytes
88
A moderately elevated WBC count (<50 WBCs/µL) with increased normal and reactive lymphocytes and plasma cells may indicate
Multiple sclerosis or other degenerative neurologic disorders
89
Increased eosinophils are seen in the CSF in association with
Parasitic infections
Fungal infections
Introduction of foreign material, including medications and shunts, into the CNS
90
The purpose of macrophages in the CSF
Remove cellular debris and foreign objects
91
Macrophages appear within _____ after RBCs enter the CSF
2-4 hours
92
The finding of increased macrophages indicates
Previous hemorrhage
93
Nonpathologically significant cells seen in CSF
Choroidal cells
Ependymal cells
Spindle-shaped cells
94
Cells seen in acute leukemia
Lymphoblasts, myeloblasts, and monoblasts in the CSF
95
Malignant cells of nonhematologic origin
Metastatic carcinoma cells
Primary CNS tumors
96
Reference values for CSF chemicals are the same as the plasma values. True or False?
False; not the same
97
Reference values for total CSF protein
15-45 mg/dL
98
Major CSF protein
Albumin
99
Second most prevalent fraction in CSF
Prealbumin (Transthyretin)
100
Alpha globulins
Haptoglobin, ceruloplasmin
101
Major beta globulin present
Transferrin
102
Used to identify CSF
Tau
103
CSF gamma globulin
IgG, with only a small amount of IgA
104
Not found in normal CSF
IgM, fibrinogen, and beta lipoprotein
105
Used to evaluate the integrity of the blood-brain barrier
CSF/serum albumin index
106
Normal value of CSF/serum albumin index
<9
107
Normal value of CSF/serum albumin index indicates
Intact BBB
108
Abnormal value of CSF/serum albumin index
>9
109
CSF/serum albumin index of 100 is indicative of
Complete damage to BBB
110
Used to measure IgG synthesis within the CNS
CSF IgG index
111
Normal value of CSF IgG index
<0.70
112
Abnormal value of CSF IgG index
>0.70
113
IgG production within the CNS indicates pathologic immune reaction
Multiple Sclerosis
114
The primary purpose for performing CSF protein electrophoresis
Detect oligoclonal bands
115
Oligoclonal bands in CSF protein electrophoresis indicates
Inflammation within the CNS
116
The presence of two or more oligoclonal bands in the CSF that are not present in the serum can be a valuable tool in diagnosis of:
Multiple Sclerosis
Encephalitis
Neurosyphilis
Guillain-Barré syndrome
Neoplastic disorders
117
The presence of myelin basic protein (MBP) in the CSF indicates
Recent destruction of the myelin sheath that protects the axons of the neurons (demyelination)
118
Reference value for CSF glucose
60%-70% that of the plasma glucose
119
A markedly decreased CSF glucose level accompanied by an increased WBC count and a large percentage of neutrophils indicates
Bacterial meningitis
120
A markedly decreased CSF glucose level accompanied by an increased lymphocytes instead of neutrophils
Tubercular meningitis
121
Normal CSF glucose value is found with an increased number of lymphocytes
Viral meningitis
122
Elevated CSF glucose values are always a result of plasma . True or False?
True
123
Valuable aid in diagnosing and managing meningitis cases
CSF lactate
124
Normal value for CSF lactate
10-24 mg/dL (1.1-2.4 mmol/L)
125
CSF lactate of >25 mg/dL indicates
Bacterial, tubercular, and fungal meningitis
126
CSF lactate of >35 mg/dL indicates
Bacterial meningitis
127
CSF lactate of <25 mg/dL indicates
Viral meningitis
128
Normal CSF glutamine
8-18 mg/dL
129
Disturbance of consciousness is seen when glutamine levels
>35 mg/dL
130
Help diagnose meningitis by confirming the presence of PMN and lymphocytes
Lactate Dehydrogenase Isoenzyme
131
Increased LD1 and LD2 Isoenzyme
Brain tissue destruction
132
Increased LD2 and LD3 Isoenzyme
Viral meningitis
133
Increased LD4 and LD5 Isoenzyme
Bacterial meningitis
134
Normal serum LDH:
LD 2>1>3>4>5
135
Flipped pattern (AMI) serum LDH:
LD 1>2>3>4>5
136
Normal CSF LDH:
LD 1>2>3>4>5
137
Bacterial meningitis CSF LDH
LD 5>4>3>2>1
138
The role of the microbiology laboratory in analyzing CSF
Identify the causative agent in meningitis
139
Duration of CSF culture for bacterial meningitis
24 hours
140
Duration of CSF culture for tubercular meningitis
6 weeks
141
In gram stain, CSF should be centrifuged at
1500 g for 15 minutes
142
Source of false positive interference in latex agglutination assay
Rheumatoid factor
143
Uses blood cells of the horseshoe crab (Limulus polyphemus) termed "amebocytes" which contains copper complex responsible for the blue color
Limulus lysate test
144
Diagnosis of meningitis caused by gram negative organisms by detecting endotoxins found in their cell walls
Limulus lysate test
145
Meningitis exhibiting pellicle/ weblike clot formation
Tubercular meningitis
146
Appearance of Cryptococcus neoformans in gram stain
Classic starburst pattern
147
Serologic testing of the CSF is performed to detect the presence of
Neurosyphilis
148
Procedure recommended by the CDC to diagnose neurosyphilis
Venereal Disease Research Laboratories (VDRL)
