Csf Flashcards
outermost membrane outermost membrane
dura matter
middle
* Pia mate
Arachnoid mater/Arachoidea “spider-web-like”
innermost layer and
adheres to the surface pf neural tissue.
- Pia mater “gentle mother”
Functionof csf
- Serves as a mechanical barrier against trauma
- Provides supply of nutrient to CNS tissue
- Remove metabolic wastes
CSF is produced via active transport secretion and filtration by the
____ of each of the four ventricles of the brain
choroid plexuses
Rate of production:
0.3 to 0.4 mL/min, ~ 20 mL/hr
volume adults
140 to 170 mL or 90 to 150 mL
neonates volume
10 to 60 mL
Used to represent the control and filtration of blood
components to the CSF and to the brain
Brain-Blood Barrier (BBB
In the choroid plexuses, the endothelial cells have a very tightfitting junctures that prevent the passage of many molecules.
These structures are termed as the
Brain-Blood Barrier (BBB)
- routine method for CSF collection, done
with fetal position or lateral decubitus position
lumbar puncture
sites of lumbar puncture inadults
Between 3rd and 4th (or lower) lumbar vertebrae
site of lumbar puncture in children
Between 4th and 5th lumbar vertebrae
puncture in sub-occipital region (cisterna magna)
Cisternal puncture
puncture for - infants with open fontanels
Ventricular puncture
order of collection: 1st tube test and storage?
Chemical and serological test; frozen at -15 to 30 deg cel
order of collection: 2nd tube
Microbiological test; room temp at 19 to 26deg cel
Order of collection; 3rd tube
cell count; refrigerated at 2 to 8 deg cel
tube 4
microbiology to chemistry or serology
order or collection; low volume csf
micro to hema to chem
order of collection; excess csf
mix together
stat basis
within 30 minutes
Appearance and color
clear and colorless
pH
7.4
Daily secretion
450-500mL
SG
1.006-1.007
Lymphocytes
1.5/HPF
Protein
15-45 mg/dL
Glucose
50-80 mg/dL
Chloride
115-130 mmol/L
Calcium
1.0-1.4 mmol/L
Phosphorus
0.4-0.7 mmol/L
Magnesium
1.2-1.5 mmol/L
Potassium
1.2-1.5 mmol/L
Clot formation but no blood
meningitis, Froin’s syndrome
Web-like/ pine tree clot, no blood
tubercular meningitis
Pellicle formation
suppurative meningitis
Clot formation + blood
traumatic tap
- Most frequently performed chemical test on CSF
Protein
Normal Values:
* 6 months to adults of protein
15 to 45 mg/dL
Normal Values:Newborns =Protein
75 to 150 mg/dL
Normal Values:>60 years oldProtein
> 60 mg/dL
proteins to be tested first to last
Albumin> Prealbumin> Haptoglobin and Ceruloplasmin>
transferrin
comparison between serum an CSF levels of
albumin and IgG must be made
- Protein Fraction
Normal Protein Fractions:
Albumin, Prealbumin, Alphaglobulins (Haptoglobin and Ceruloplasmin), Transferrin, TAU
protein, IgG, and IgA
Protein Fractions not normally found in CSF
IgM,
Fibrinogen, Beta-lipoproteins
Ammonium sulfate
Cloudy precipitate
Nonne-Apelt
Ammonium sulfate
White ring
Rose Jones
Phenol
Bluish white cloud
Randy’s
10% Butyric acid
Precipitate
Nogochi
Colloidal Gold
Solution
1+: Blue
2+: Purple
3+: Deep Blue
4+: Pale Blue
5+: Colorless
Colloidal Gold
Test
reagent of choice,
precipitates both albumin and globulins
Trichloroacetic acid (TCA):
precipitates albumin only
unless Na2SO4 is added
Sulfosalicylic acid (SSA):
Dye-Binding Techniques PRINCIPLE
: Protein Error of Indicators
Nephelometry test what
Benzalkonium chloride
Most frequently performedquantitative test
- Method of choice for the determination of CSF
Electrophoresis
- Detection of Oligoclonal Bands: Present in CSF but not in serum:
Multiple sclerosis,
Encephalitis, neurosyphilis, Guillain-Barre
syndrome, and Neoplastic disorders
Detection of Oligoclonal Bands: Present in both:
systemic and neurologic
involvement seen in leukemia, lymphoma, viral
infections
- Evaluates BBB integrity
CSF-Serum Albumin Index
index value for intact BBB
<9
index value for damaged BBB
> 9
Determines IgG production within the CNS
CSF-Serum IgG Index
index value of CNS serum IgG
> 0.77
normal values of glucose
60-70%
normal values of glucose in neonates
80%
Plasma sample should be collected ___prior to spinal tap
2 hours
glucose Should be tested immediately to prevent significant loss due
to
glycolysis
bacterial meningitis glucose
decreased glucose but inceased neutrophils
tubercular meningitis glucose
decreased but increased lymphocytes
Viral meningitis glucose
normal and increased lymphocytes
fungal meningitis glucose
normal ord decreased plus india ink for Candida neoformans
lactate function
- Aids in diagnosis and management of meningitis
- Used to evaluate effectiveness of antibiotic therapy
- Used to monitor severe head injuries
viral meningitis lactate value
<25 mg/dL:
tubercular and fungal meningitis lactate value
> 25 mg/dL:
bacterial meningitis lactate
> 35 mg/dL
Frequently performed in CSF but not in blood
Glutamine
Indirect measure of CSF ammoni
Glutamine
It is the metabolic product from the removal of ammonia
Glutamine
normal values of glutamine
8-18 mg/dL
clinical significance of glutamine
- Disturbance in consciousness (>35 mg/dL)
- Coma of unknown origin (result from increased usage of
alpha-ketoglutarate) - Reye’s syndrome (75% of diagnosed children)
Aids in the diagnosis of meningitis
Lactate Dehydrogenase Isoenzymes
LD: brain and tissue destruction
LD1 and LD2
LD: viral meningitis
LD2 and LD3
LD: bacterial meningitis
LD4 and LD5
CK-BB Isoenzymes value in post-cardiac arrest indicates poor prognosis
> 17 mg/dL
CK-BB Isoenzymes value indicates recovery from cardiac arrest after
resuscitation
<17 mg/dL
All specimens should be examined microscopically — sample
may appear clear even it contains WBCs (up to ___L) or
RBCs (up to ___)
200/uL;400/uL
WBCs and RBCs disintegrate within ___ and
about 40% of WBCs disintegrate after __
one hour; two hous
WBC predominant in adults
Lymphocyte
lympo to mono ratio in adult
70:30
WBC predominant in children
monocyte
lympo to mono ratio in children
30:70
rare normal cell component
neutrophils
↑numbers of normal cells (abnormal finding
pleocytosis
Performed when there is:
(1) traumatic tap,
(2) a need for
leukocyte correction, and
(3) a need for protein correction
RBC Count
diluent of total cell count
NSS
normal wbc count in adult
0 to 5 WBCs/uL
Normal WBC count in neonates
0 to 30 mononuclear cells /uL
dilutent of WBC count
3% glacial acetic acid
Stain of WBC count
methylene blue
If, peripheral RBC and WBC counts are normal, subtract
___ WBC for every ____ RBCs present in CSF
subtract
1 WBC for every 700 RBCs
Sample is undiluted and examined using a phase-contrast
microscopre
Fuchs-Rosenthal Counting Chamberr
With 16 large squares and 0.2 mm depth
Fuchs-Rosenthal Counting Chamber
- Specimens are concentrated and stained
differential Count
differential Count number of cells counted
100
causes less cell distortion; not routinely
performed
✓ Sedimentation
causes less cell distortion; not routinely
performed
Filtration
✓ Cytocentrifugation:
0.1 ml CSF + 1 drop 20% albumin
(↑cell yield and ↓distortion) → centrifugation for 5 to
minutes → Wright’s staining
Performed to identify the causative agent in meningitis
Microbiological Examination
specimen for micro examination
CSF and blood
Microbiological Examination Specimens should be concentrated by centrifugation at
1500xg for 15 minutes
Microorganism must be recovered from CSF by growing it on
appropriate culture medium for positive identification
Blood Culture
Blood Culture Duration of incubation: 24 hour
bacterial meningitis
Blood Culture Duration of incubation: 6 weeks
tubercular meningitis
Blood Culture Medium:
Thioglycolate broth, chocolate agar
Blood Culture sensitivity
80-90%
Confirmatory procedure rather than diagnostic
Blood Culture
Routinely performed on CSF from all suspected cases of
meningitis
Gram Staining
Recommended method for the detection of organisms
Gram Staining
___ of organism should be present for adequate Gram
stain results
106^5
/ml
Star burst pattern:
Cryptococcus neoformans
Performed when tubercular meningitis is suspected
Positive report is extremely valuable
Acid Fast/Fluorescent Antibody Stains
Detect the presence of a thickly encapsulated Cryptococcus
neoformans
India Ink
More sensitive method in the detection Cryptococcus
neoformans in serum and CSF
Reverse Latex Agglutination
- Used in combination with hematology and clinical chemistry
results
Bacterial Antigen Test
Should be confirmed by culture and India ink
- False positive reactions occur mainly due to rheumatoid
factor
Reverse Latex Agglutination
Provide rapid means for detecting and identifying
microorganisms in CSF
Latex Agglutination Tests and ELISA
Diagnosis of meningitis caused by Gram (-) organisms
Limulus Lysate Tes
Performed for the diagnosis of neurosyphilis
Veneral Disease Research Laboratories (VDRL)
Most sensitive and specific for syphilis diagnosis
Fluorescent Treponemal Antibody-Absorption (FTA-ABS)
reagent of Limulus Lysate Test
Blood cells (amebocyte) of horseshoe crabs
(Limulus polyphemus) → blue in color due to the presence of
a copper comple
Limulus Lysate Test Principle:
The endotoxin produced by the cell walls of Gram
(-) organisms will coagulate the amebocyte lysate within 1
hour incubated at 37oC
