(P) Lec 5: Body Fluid Analysis (CSF) Flashcards
- This fluid occupies the spaces of the CNS (between the arachnoid and pia mater)
- It flows through the subarachnoid space and is reabsorbed in the arachnoid granulations/villi
Cerebrospinal Fluid (CSF)
CSF
What structure is responsible for the formation of CSF?
Choroid plexus (made up of ependymal cells)
CSF
How much CSF is produced (3 values):
- per hour
- per minute
- per day
- Per hour: 20mL/hour
- Per min.: 0.4mL/min.
- Per day: 480-500mL/day
CSF
Give the total volume of CSF:
- For adults
- For neonates
- Adults: 90-150mL
- Neonates: 10-60mL
CSF
Refers to the membranes covering the brain and spinal cord
Meninges
CSF Functions
- It protects and supports the ____ and spinal cord
- Provides a medium for the transport and exchange of ____ and metabolic wastes
- Brain
- Nutrients
CSF
Refers to a tight fitting structure of the endothelial cells in the choroid plexuses that controls the passage of substances in the blood to the brain & CSF
Blood-Brain Barrier
CSF Collection
A lumbar puncture (spinal tap) is done between what vertebrae of:
- Adults
- Neonates
- Adults: between L3 and L4
- Neonates: L4 and L5
CSF
In CSF collection, what are the tests performed for tubes 1, 2, 3, and 4?
- Chemistry/Serology
- Microbiology
- Hematology
- Cytology/Microbiology
CSF
In CSF collection, how would you preserve tubes 1 (chemistry), 2 (microbiology), and 3 (hematology)?
- Freeze
- Room temperature
- Refrigerate
CSF
Which of the ff. is NOT an indication for CSF testing?
- CNS infection
- CNS hemorrhage
- Demyelinating disease
- Clotting problems within the brain vessels
- Malignancy
Clotting problems within the brain vessels
CSF
What is the normal color and transparency of CSF?
Colorless and Clear
Indicates that the sample is free of clots and blood
CSF
This refers to a web-like clot that is highly indicative for TB
Pellicle formation
CSF
A traumatic spinal tap and subarachnoid hemorrhage will produce a sample that contains what?
Blood
CSF
Traumatic Tap or Intracerebral Hemorrhage?
- Uneven distribution of blood
- Clot formation
- Supernatant is NOT xanthochromic
Traumatic tap
CSF
Traumatic Tap or Intracerebral Hemorrhage?
- Even distribution of blood
- No clot formation
- Supernatant is xanthochromic
- There is erythrophagocytosis and is (+) for D-dimer
- Contains hemosiderin-laden macrophages
Intracerebral Hemorrhage
CSF
Among the ff.:
- Protein
- Glucose
- Chloride
- Sodium
- Potassium, Calcium, and Bicarbonates
Which among them are lower/higher in CSF than in plasma?
- Lower: Protein, Glucose, K, Ca, and Bicarbonates
- Higher: Chloride and Sodium
CSF
- Protein levels are lower in CSF than in plasma as they contain no ____
- Glucose is 2/3 the volume of ____
- Fibrinogen
- Blood sugar
CSF
Chloride is how many percent higher in CSF than in plasma?
25%
CSF
- Glucose in CSF is vital distinguishing various causes of ____
- What are the normal values of CSF glucose compared to plasma glucose?
- Blood glucose should be drawn ____ hours prior to a spinal tap
- Meningitis
- 60-70% of plasma glucose
- 2-4 hours
CSF
What do the ff. events cause (1 answer)?
- A disorder of the carrier-mediated transport of glucose into CSF
- There is active metabolism of glucose by cells or organisms (e.g. bacterial meningitis)
- Increased metabolism of glucose by the CNS (e.g. meningeal neoplasia & brain tumor)
Hypoglycorrhachia (decreased CSF glucose)
CSF
This analyte test is maintained by the integrity of the BBB as it controls the passage of substances in the blood to the brain & CSF
Protein Chemical Test
CSF
- Give the normal value of CSF protein (CHON)
- Is CSF protein slightly higher in infants, elderly, or middle aged adults?
- 15 to 45mg/dL (0.5%-1% of plasma)
- Higher in infants and elderly
CSF
Give the proteins found in CSF with their descriptions:
1. The major CSF protein
2. The 2nd most prevalent protein
3. Alpha-globulins (2)
4. The major beta-globulin
5. Gamma-globulins (2)
6. A carbohydrate-deficient fraction of transferrin
- Albumin
- Prealbumin (transerythrin)
- Haptoglobin and Ceruloplasmin
- Transferrin
- IgG and IgA (small amount)
- Tau (B2 Transferrin)
CSF
What 3 proteins are NOT normally found in CSF?
- IgM
- Fibrinogen
- Beta-lipoprotein
CSF
TOF: Tau (B2 Transferrin) is seen ONLY in CSF and not in serum
True
CSF
Causes of INCREASED CSF protein:
1. ____ of blood
2. Increased ____ of the membrane (meningitis)
3. Increased ____ of the CNS tissue (MNS and SSPE)
4. ____ as the case with tumors and abscesses
5. A decreased rate in ____
Note: MS (multiple sclerosis) and SSPE (sub-acute sclerosing panencephalitis)
- Lysis
- Permeability
- Production
- Obstruction
- Removal
CSF
This is the most common inflammatory demyelinating disease of the CNS
Multiple Sclerosis
CSF
Causes of DECREASED CSF protein:
1. Decreased ____ from plasma
2. Increased ____ loss
3. Leakage of CSF from a tear in the ____ leading to otorrhea or rhinorrhea
- Dialysis
- Protein
- Dura
CSF
What are the 2 turbidimetric methods for measuring CSF protein?
- Trichloroacetic Acid (TCA)
- Sulfosalicylic Acid (SSA)
CSF
Turbidimetric methods for measuring protein:
1. This one is preferred because it precipitates albumin and globulin equally
2. This should be combined with sodium sulfate
- Trichloroacetic Acid (TCA)
- Sulfosalicylic Acid (SSA)
CSF
This protein measurement method:
- Allows for dyes to bind with the protein
- Is faster and more accurate
- Only needs a small amount
- Has Coomasie Brilliant Blue as an example
Dye-binding Techniques
CSF
These protein fractions:
1. Are produced in the liver and are present in the CSF because of membrane transport mechanisms
2. Are immune entities that can be produced in the CSF
- Albumin
- Immunoglobulins
CSF
Give the ff. indices:
1. This measures the integrity of the BBB
2. Detects the production of immunoglobulin in CSF
- CSF/Serum Albumin Index
- CSF/IgG Index
CSF
- In the CSF/Serum Albumin index, a ratio of ____ indicates a damaged BBB (meningitis)
- In the CSF/IgG index, the normal value is ____ while an index of ____ suggests multiple sclerosis
- > 9
- < 0.73; > 0.77
CSF
This is the method used for the identification of the tau isoform of transferrin
Electrophoresis
CSF
What is the common medium used for CSF electrophoresis?
Agarose Gel
CSF
2 or more oligoclonal bands in CSF, but not in serum, indicate the production of ____ in the CNS
Immunoglobulins
CSF
Give the ff. diseases:
1. Is only found in CSF
2. May also produce oligoclonal banding that may not be present in the serum (4)
3. Found in CSF and in the blood
- Multiple Sclerosis
- SSPE (encephalitis), neurosyphilis, Guillain-Barrésyndrome, and neoplastic disorders
- AIDS
CSF
This protein indicates recent destruction of the myelin sheath that protects the axons of the neurons (demyelination) and is used a marker for the progression of multiple sclerosis
Myelin Basic Protein (MBP)
CSF
- This is an indicator of anaerobic metabolism within the CSF
- It can distinguish bacterial from viral meningitis
- Is increased in tissue destruction within the CNS (hypoxia)
Lactate
CSF
What is the normal value for lactate in the CSF?
10-22 mg/dL (or 10-24)
CSF
Give the type of meningitis correspondent to the lactate level:
1. > 35mg/dL
2. > 25mg/dL but < 35mg/dL
3. < 25mg/dL
- Bacterial meningitis
- Tubercular or fungal meningitis
- Viral meningitis
CSF
- This is produced from ammonia and alpha-keto glutarate by the brain cells
- Also serves as an indirect test for ammonia in CSF
Glutamine
Note: Glutamine is more stable than ammonia
CSF
What 3 conditions elevate CSF glutamine levels?
- Liver disease
- Reye’s syndrome
- Hepatic encephalopathy
