Cerebrospinal Fluid Flashcards
What are the functions of the CSF?
• Cushions the brain and spinal cord
• Provides a system to supply nutrients to the nervous tissue
• Removes metabolic wastes and other wastes
How much CSF is produced every hour?
20 mL
How much total volume of CSF are in neonates?
10-60 mL
How much total volume of CSF are in adults?
90-150 mL
CSF is produced in the ______.
Choroid plexus
How does CSF form? Give the flow of its formation.
—>Produced bythe choroid plexus from the lateral ventricle.
—>Passes through the foramina of Monro towards the 3rd ventricle
—>Passes through the Sylvian aqueduct towards the 4th ventricle
—>Passes through the foramen of Luschka and Magendie towards the Cisterna Magna
—>Subarachnoid space
The build-up of CSF in the aqueduct of Sylvius can lead to what condition?
Hydrocephalus
How does the CSF exit the nervous system?
Via arachnoid granulations
What is the procedure called for collecting CSF
Lumbar puncture / spinal tap
What are the allowable positions of the patient when collecting CSF? Which one is the most common? When is the other one used?
Lateral recumbent - most common
Sitting - px w/ pulmonary problem
What are the disinfectants used when collecting CSF? What is the alternative when the patient is allergic?
Betadine or povide iodine;
Chlorhexidine
Local anesthetic that is commonly used in collecting CSF
Lidocaine
Where is CSF collected specifically?
Between L3 and L4 - adults
Between L4 and L5 - children
How many tubes are usually collected and what is the section order? At what temp are they kept?
3 tubes
Tube 1: CC and serology (frozen)
Tube 2: Microbio (RT)
Tube 3: Hema (refrigerated)
When there’s only 1 tube of CSF collected, what is now the order when submitting it to the laboratory?
Micro -> hema -> CC
What is the normal appearance of the CSF?
Crystal clear / colorless
Appearance of the CSF when it is high on protein/lipid/WBC
Cloudy / turbid
The term used when the supernatant is pink, orange, or yellow
Xantochromia
How do we observe xantochromia from a sample?
Centrifuge the sample first then observe the supernatant’s color
What is the reason for this color?
Brown
Methemoglobin
What is the reason for this color?
Pink
Oxyhemoglobin
What is the reason for this color?
Yellow
Bilirubin
What is the reason for this color?
Orange
Combination of oxyhemoglobin, bilirubin, & carotene
What should be the first thing you should think of when then CSF is red?
Presence of RBCs
How is intracranial hemorrhage differentiated from traumatic tap?
Uneven distribution of blood
What does IH and TT look like when compared?
IH - red in all 3 tubes
TT - red intensity lowers toward 3rd tube
Which of the two (IH & TT) has clot present, and why does the other one do not have clot formation?
TT - clot present
IH - no clot, because it could’ve dissolved or not enough fibrinogen to form the clot
What is the clot that is formed when the CSF is refrigerated for at least 12 hours? When is it usually seen?
Web-like pellicle
Px w/ tuberculosis
In what tube is CSF WBC count normally performed?
Tube 3
Normal adult CSF contains ______ WBCs/microL.
0-5
CSF WBC counting is performed using ______.
Neubauer counting chamber
Alternative for centrifugation for getting the sediment of the CSF
Filtration
The best method for concentrating the CSF sediment
Cytocentrifugation
If the WBC count is <100, what is the next step?
Differentiate then report, but report regardless of the number.
In adults, what is the L/M ratio?
70:30
In children, what is the L/M ratio?
30:70
When WBC count exceeds the number of lymphocytes and monocytes, what is the most probable cause to it?
Bacterial meningitis
True or false:
Is the presence of eosinophil normal like in the urine?
False
Reactive lymphocytes are also known as _____.
Turk’s cells
What is the appearance of reactive lymphocyte?
Dark blue cytoplasm w/ clumped chromatin
Reactive lymphocytes are seen in _____.
Viral infections
Proteins that are normally found in the CSF
Transthyretin (prealbumin)
Albumin
Transferrin
What does it mean usually when the CSF protein levels increase? What are the other considerations?
Damaged blood-brain barrier
Contamination from TT
Blockage in the granulations
Meningitis
What protein is best used to assess the BBB’s integrity?
Albumin
If IgG levels are high, _____ should be suspected.
Multiple sclerosis
What is the hallmark of multiple sclerosis?
Oligoclonal bands
