CSF analysis Flashcards
it is a major fluid of the body. CSF provides a physiologic system to supply nutrients to the nervous tissue, remove metabolic wastes, and produce a mechanical barrier to cushion the brain and spinal cord against trauma
Cerebrospinal fluid (CSF)
Enumerate the purposes of CSF examination
1) Evaluate the function of the Central Nervous System
2) CSF greatly indicates presence of infections, autoimmune disorders, diseases of the brain & the spinal cord (such as encephalitis, meningitis, multiple sclerosis, & hemorrhage)
3) Detects early signs of seizures & dementia
CSF covers what parts of the CNS?
- Brain
- Spinal cord
Main source of CSF; Comprises 70% of the CSF formation
Choroid plexus
Comprises 30% of the CSF formation
Subarachnoid space
Epithelial cells that lines the choroid plexus; main cells responsible for the formation of the blood- brain barrier
Choroidal cells
Regulates the movement of ions, molecules, and cells between the blood and the brain
Blood brain barrier
What are the layers of the brain (meninges)?
- Dura mater
- Arachnoid space
- Pia mater
what are the three (3) types of epithelial cells?
- Ependymal cells
- Choroidal cells
- Pia Arachnoid Mesothelial cells (PAM)
*Cells that lines the cerebral ventricles & neural canals of the spinal cord
*Range in shape from squamous to columnar
*May be ciliated
Ependymal cells
these cells lines the mesoderm of the pia & arachnoid layers
Pia Arachnoid Mesothelial cells (PAM)
what are the CSF ion components?
- H, K, Ca, bicarbonate and, Mg
T or F: Glucose, urea and creatinine diffuse freely and require 2 or more hours to regulate
True
How many CSF is produced each day?
500 mL (0.3 - 0.4 mL/min)
Volume of CSF in adults?
- 90 - 150 mL
- 25 mL in the ventricles and subarachnoid space
Volume of CSF in neonates?
10 to 60 mL
How many hours does CSF is replaced?
every 5 to 7 hours
Common site for lumbar puncture is the intervertebral space
Adult:
Children:
- between L3 and L4
- between L4 and L5
CSF obtained through what procedure?
cisternal or lumbar puncture through ventricular cannulas or shunts
Normal opening pressures
adults:
obese:
infants & children:
- 90 to 180 mm of water
- 250 mm of water
- 10 to 100 mm of water (6-8 yrs)
greater then 250 mm of water opening pressure indicates what underlying conditions?
- increased intracranial pressure which might be caused by meningitis, intracranial hemorrhage & tumors
what precaution should be observed when there is >200 opening pressure in a relaxed patient?
- no more than 2.0 ml should be withdrawn
this tool indicates the pressure of the CSF fluid
Manometer
Distribution of CSF tubes
Which lab section does tube #1 belongs to and what tests are applied?
- Chemistry and/or Serology section
- protein, glucose, lactate, VDRL, latex agglutination test
Distribution of CSF tubes
Which lab section does tube #2 belongs to and what tests are applied?
- Microbiology section
- Gram stain, culture and India ink
Distribution of CSF tubes
Which lab section does tube #3 belongs to and what tests are applied?
- hematology section
- cell count and differential
Microbiology should be stored in what tube?
- tube 2 (sterile)
Gross examination
Normal CSF color and appearance
- Crystal clear and colorless
Gross examination
What are the causes for turbidity or cloudiness of CSF specimens?
- WBC > 200/uL
- RBC > 400/uL
- Microorganisms
- radiographic contrast media
- aspirated epidural fat
- proteins > 150 mg/ dL ( 1.5 g/L)
Gross examination
What are the causes for bloody/pink specimen
- RBC > 6000/uL
- Subarachnoid and Intracerebral hemorrhage;
- cerebral infarct or traumatic spinal tap
pertains to the presence of oxidized hemoglobin from lysed RBCs
Xanthochromia
Give the corresponding causes for xanthochromia of CSF
pink: ________
orange : ________
________ : RBC lysis/hemoglobin breakdown
________ : Hyperbilirubinemia (biliverdin)
Brown : ________
- RBC lysis
- RBC lysis/hemoglobin breakdown
- yellow
- green
- Meningeal matastatic melanoma
*2-4 hrs after subarachnoid hemorrhage and take as long as 12 hrs, peak 24- 36 hrs and disappears on 4-8 days
*Hypervitaminosis A (carotenoids)
Orange xanthochromia
*Hyperbilirubinemia; develops after 12 hrs after subarachnoid bleed, peaks 2-4 days and persists for 2-4 weeks
*CSF protein > 150 mg/dL (1.5 g/L)
Yellow xanthochromia
Differentiate Hemorrhage from traumatic tap in terms of appearance, supernatant. and presence of clots
Hemorrhage: all tubes equally red (bloody), xanthochromic, and absent
Traumatic tap: subsequent clearing in each tube, clear, and present due to fibrinogen
Causes for Clot formation in CSF samples
- Traumatic taps
- Complete spinal block (Froin’s syndrome)
- Suppurative or tuberculous meningitis
Causes for Viscous CSF samples
- Metastatic mucin producing adenocarcinomas
- Cryptococcal meningitis
- Liquid nucleus pulposus
T or F: Proper storage of CSF must be at room temperature and should be examined immediately
True
*18 large squares (1mm^2)
*depth of 0.2 mm
*total volume of 3.6 uL
*CV = 48%
Fuch’s-Rosenthal chamber
*9 squares (1mm each)
*depth of 0.1mm
*CV = 45%
Neubauer hemocytometer
Yield rapid and reliable WBC and RBC counts
UF-100 flow cytometer
Normal leukocyte count
adult:
neonates:
- 0-5 cells/uL
- 0-30 cells/uL
recommended method for the differential count of all body fluids
cytocentrifuge
Disadvantages in performing differential count in counting chamber
- unsatisfactory because of low numbers and low precision
- Direct smears of the centrifuged CSF sediment are also subject to significant error from cellular distortion and fragmentation
WBC added = ?
leukocytes added to CSF by traumatic tap
Stain used for CSF
Wright’s stain
Lymphocyte to monocyte ratio among adults
70:30 ratio
CSF examination for tumor cells has the sensitivity to:
Leukemic patients
Metastatic carcinoma
Primary CNS malignancies
- 70%
- 20-60%
- 30%
dark blue cytoplasm & clump chromatins; can also be seen during Multiple sclerosis
Reactive lymphocyte
Presence of ___________ in CSF indicates previous hemorrhage
Macrophage
1% of the plasma level
Increase proteins = pathologic conditions
Decrease proteins = fluid leakage
CSF Protein
Reference value
Adults: ________
CSF protein fell rapidly from birth to 6 months of age ___________
plateaud 3-10 years __________
rose slightly from 10-16 years of age __________
Classic Lowry method __________
Trichloroacetic acid- ponceau S method ___________
Biuret method
- 15-45 mg/dL
- 118 →40 mg/dL
- 32 mg/dL)
- 41 mg/dL
- 24.1- 48 mg/dL
- 15-49 mg/dL
- 22.3-50.3 mg/dL
___________ makes up most of CSF protein
Albumin
___________ is the second most prevalent fraction in CSF.
Serum albumin
*Seen in MS Correlate with CSF leukocyte count,
*Surrogate marker during acute MS exacerbations
Myelin Basic Protein
Increased in pinocytic vesicles which reflects hemorrhage or breakdown of BBB, as occurs in bacterial meningitis
Alpha-2-macroglobulin (A2M)
*Marker of neuro-Bechet’s syndrome
*HIV-1 and various malignancies have been associated
Beta-2-macroglobulin (B2M)
Differentiating viral (aseptic) meningitis from bacterial meningitis
C-Reactive Protein
Cell adhesion allows leukocytes to adhere and pass through the vascular endothelia and migrate to the inflammatory site
Fibronectin
*present in Creutzfeldt-Jacob disease (CJD)
*Determined by immunoassay
&False (+) = stroke and meningoencephalitis
Protein 14-3-3
Subarachnoid hemorrhage and intracerebral hemorrhage
Methemoglobin and bilirubin
________ present in the body
________ that is only present in the CNS
Beta-1-transferrin
Beta-2-transferrin
this enzyme converts Beta-1-transferrin
neuroaminidase
Normal values for CSF glucose
50-80 mg/dL (60% plasma values)
T or F: Results should be compared with plasma following 4 hour fast
True
Normal values for CSF lactate
children & adults
newborns for the 1st 2 days of life
3 to 10 days old
tissue hypoxia
- 0-26 mg/dL (1.0- 2.9 mmol/L)
- 10-60 mg/dL
- 10-40 mg/dL (1.1- 4.4 mmol/L)
- Elevated levels reflect CNS anaerobic metabolism
Normal values for CSF Lactate
Viral meningitis
Bacterial meningitis
- > 25 mg/dL
- > 35 mg/dL; cut off value 30-36 mg/dL
Elevated levels in existing hepatic encephalopathy
CSF Glutamine
synthesized from ammonia and glutamic acid serves as the means for CNS ammonia removal
cerebral Glutamine
Normal values of CSF Glutamine
8-18 mg/dL
Gram’s stain sensitivity ranges from __________ with greatest sensitivity corresponding to higher concentrations of bacteria
60-90%
Immunochromatographic membrane assay with Streptococcus Latex agglutination bacterial antigen on which microorganisms?
- Haemophiles influenzae,
- Neisseria meningitidis
- Streptococcus pneumoniae
When performing microbiological studies, CSF samples must kept at?
room temperature