Cerebrospinal Fluid

Question 1

What are the functions of the CSF?

Answer 1

• Cushions the brain and spinal cord
• Provides a system to supply nutrients to the nervous tissue
• Removes metabolic wastes and other wastes

Question 2

How much CSF is produced every hour?

Answer 2

20 mL

Question 3

How much total volume of CSF are in neonates?

Answer 3

10-60 mL

Question 4

How much total volume of CSF are in adults?

Answer 4

90-150 mL

Question 5

CSF is produced in the ______.

Answer 5

Choroid plexus

Question 6

How does CSF form? Give the flow of its formation.

Answer 6

—>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

Question 7

The build-up of CSF in the aqueduct of Sylvius can lead to what condition?

Answer 7

Hydrocephalus

Question 8

How does the CSF exit the nervous system?

Answer 8

Via arachnoid granulations

Question 9

What is the procedure called for collecting CSF

Answer 9

Lumbar puncture / spinal tap

Question 10

What are the allowable positions of the patient when collecting CSF? Which one is the most common? When is the other one used?

Answer 10

Lateral recumbent - most common
Sitting - px w/ pulmonary problem

Question 11

What are the disinfectants used when collecting CSF? What is the alternative when the patient is allergic?

Answer 11

Betadine or povide iodine;
Chlorhexidine

Question 12

Local anesthetic that is commonly used in collecting CSF

Answer 12

Lidocaine

Question 13

Where is CSF collected specifically?

Answer 13

Between L3 and L4 - adults
Between L4 and L5 - children

Question 14

How many tubes are usually collected and what is the section order? At what temp are they kept?

Answer 14

3 tubes

Tube 1: CC and serology (frozen)
Tube 2: Microbio (RT)
Tube 3: Hema (refrigerated)

Question 15

When there’s only 1 tube of CSF collected, what is now the order when submitting it to the laboratory?

Answer 15

Micro -> hema -> CC

Question 16

What is the normal appearance of the CSF?

Answer 16

Crystal clear / colorless

Question 17

Appearance of the CSF when it is high on protein/lipid/WBC

Answer 17

Cloudy / turbid

Question 18

The term used when the supernatant is pink, orange, or yellow

Answer 18

Xantochromia

Question 19

How do we observe xantochromia from a sample?

Answer 19

Centrifuge the sample first then observe the supernatant’s color

Question 20

What is the reason for this color?

Brown

Answer 20

Methemoglobin

Question 21

What is the reason for this color?

Pink

Answer 21

Oxyhemoglobin

Question 22

What is the reason for this color?

Yellow

Answer 22

Bilirubin

Question 23

What is the reason for this color?

Orange

Answer 23

Combination of oxyhemoglobin, bilirubin, & carotene

Question 24

What should be the first thing you should think of when then CSF is red?

Answer 24

Presence of RBCs

Question 25

How is intracranial hemorrhage differentiated from traumatic tap?

Answer 25

Uneven distribution of blood

Question 26

What does IH and TT look like when compared?

Answer 26

IH - red in all 3 tubes TT - red intensity lowers toward 3rd tube

Question 27

Which of the two (IH & TT) has clot present, and why does the other one do not have clot formation?

Answer 27

TT - clot present IH - no clot, because it could've dissolved or not enough fibrinogen to form the clot

Question 28

What is the clot that is formed when the CSF is refrigerated for at least 12 hours? When is it usually seen?

Answer 28

Web-like pellicle Px w/ tuberculosis

Question 29

In what tube is CSF WBC count normally performed?

Answer 29

Tube 3

Question 30

Normal adult CSF contains ______ WBCs/microL.

Answer 30

0-5

Question 31

CSF WBC counting is performed using ______.

Answer 31

Neubauer counting chamber

Question 32

Alternative for centrifugation for getting the sediment of the CSF

Answer 32

Filtration

Question 33

The best method for concentrating the CSF sediment

Answer 33

Cytocentrifugation

Question 34

If the WBC count is <100, what is the next step?

Answer 34

Differentiate then report, but report regardless of the number.

Question 35

In adults, what is the L/M ratio?

Answer 35

70:30

Question 36

In children, what is the L/M ratio?

Answer 36

30:70

Question 37

When WBC count exceeds the number of lymphocytes and monocytes, what is the most probable cause to it?

Answer 37

Bacterial meningitis

Question 38

True or false: Is the presence of eosinophil normal like in the urine?

Answer 38

False

Question 39

Reactive lymphocytes are also known as _____.

Answer 39

Turk's cells

Question 40

What is the appearance of reactive lymphocyte?

Answer 40

Dark blue cytoplasm w/ clumped chromatin

Question 41

Reactive lymphocytes are seen in _____.

Answer 41

Viral infections

Question 42

Proteins that are normally found in the CSF

Answer 42

Transthyretin (prealbumin) Albumin Transferrin

Question 43

What does it mean usually when the CSF protein levels increase? What are the other considerations?

Answer 43

Damaged blood-brain barrier Contamination from TT Blockage in the granulations Meningitis

Question 44

What protein is best used to assess the BBB's integrity?

Answer 44

Albumin

Question 45

If IgG levels are high, _____ should be suspected.

Answer 45

Multiple sclerosis

Question 46

What is the hallmark of multiple sclerosis?

Answer 46

Oligoclonal bands