Cerebrospinal fluid (CSF) is a clear fluid that surrounds the brain and spinal cord, cushioning and protecting these structures. It is produced by specialized cells in the brain and absorbed by blood vessels. Around 125 mL of CSF is present at any given time, with 500 mL produced daily. CSF analysis examines the CSF for signs of infection, bleeding, tumors, or other disorders. CSF is collected via lumbar puncture, then analyzed through chemical tests of glucose, protein, cell counts, and microbiological tests. Abnormal CSF results can indicate conditions like meningitis or neurosyphilis. CSF circulation and composition are also described.

1. Cerebrospinal Fluid
General Information And Laboratory Finding
Sajjad Fadhil Kazim

2. What is cerebrospinal fluid?
CSF
definition
Is a clear fluid that surrounds the
brain and spinal cord. It cushions
the brain and spinal cord from
injury and also serves as a
nutrient delivery and waste
removal system for the brain.
CSF is manufactured
continuously in areas of the brain
called ventricles and is absorbed
by the bloodstream
Is a clear, colorless
body fluid found
within the tissue that
surrounds the brain and
spinal cord of all
vertebrates.
Is the liquid around
your brain and spinal
cord. If a doctor thinks
you have an illness that
affects your nervous
system, they might take
a sample for testing.

3. CSF is produced by specialized ependymal cells in the choroid plexus
of the ventricles of the brain, and absorbed in the arachnoid
granulations. There is about 125 mL of CSF at any one time, and about
500 mL is generated every day. CSF acts:-
• Cushion or buffer.
• Providing basic mechanical and immunological protection to the
brain inside the skull.
• CSF also serves a vital function in the cerebral autoregulation of
cerebral blood flow.
Importance of cerebrospinal fluid

4. Circulation of cerebrospinal fluid
In adults, the total volume of cerebrospinal fluid (CSF) is about 135 mL,
produced at a rate of 500 mL/day. This is predominantly formed by plasma
ultrafiltration through the capillary walls of the choroid plexuses in the brain’s
lateral ventricles. These plexuses also actively secrete small amounts of
substances such as chloride.
The fluid passes from the lateral, through the third and fourth ventricles, into
the subarachnoid space between the pia and subarachnoid mater, from where
much is reabsorbed into the circulation by arachnoid villi. The remaining fluid
flows through the subarachnoid space, completely surrounding the brain and
spinal cord; thus it supports and protects these structures against injury. Like
lymph, CSF removes waste products of metabolism.

5. Circulation of cerebrospinal fluid
Cerebrospinal fluid circulates very slowly, allowing contact with cells of the
central nervous system (CNS).The uptake of glucose by these cells probably
results in lower concentrations relative to plasma. Concentrations of analytes
in the CSF should always be compared with those in plasma because
alterations in the latter are reflected in the CSF even when CNS metabolism is
normal.
Flow is slowest, and therefore contact longest, in the lower lumbar region,
where the subarachnoid space comes to an end; therefore, the composition of
CSF from lumbar puncture is different from that of cisternal or ventricular
puncture.

6. Cerebrospinal Fluid Analysis
Uses of CSF analysis
A CSF analysis may include tests to diagnose:
• Infectious diseases of the brain and spinal cord, including:
• Meningitis and encephalitis. CSF tests for infections look at white blood cells, bacteria, and
other substances in the cerebrospinal fluid.
• Autoimmune disorders, such as Guillain-Barre Syndrome and multiple sclerosis (MS).
CSF tests for these disorders look for high levels of certain proteins in the cerebrospinal
fluid. These tests are called albumin protein and IgG/albumin.
• Bleeding in the brain.
• Brain tumors.

7. Symptoms of a brain or spinal
cord infection include:
Fever.
Severe
headache.
Seizures .
Stiff neck .
Nausea and
vomiting .
Sensitivity
to light .
Double
vision .
Changes in
behavior
Confusion
Cerebrospinal Fluid Analysis
Cases for CSF analysis
You may need a CSF analysis if you have symptoms of an infection of the brain or spinal cord,
or of an autoimmune disorder, such as multiple sclerosis (MS).

8. Cerebrospinal Fluid Analysis
CSF Specimen collection
• Patient will lie on him side with him knees pulled up toward the chest, and chin tucked
downward. Sometimes the test is done sitting up, but bent forward.
• After the back is cleaned, the health care provider will inject a local numbing medicine
(anesthetic) into the lower spine.
• A spinal needle will be inserted.
• An opening pressure is sometimes taken. An abnormal pressure can suggest an infection
or other problem.
• Once the needle is in position, the CSF pressure is measured and a sample of 1 to 10
milliliters (mL) of CSF is collected in 4 vials.
• The needle is removed, the area is cleaned, and a bandage is placed over the needle site.
He may be asked to remain lying down for a short time after the test.

9. Cerebrospinal Fluid Analysis
CSF Specimen equipment
• Dressing trolley & sharps bin
• Sterile field
• Analgesia
• Gauze swabs and small dressing
• Spinal needle (atraumatic needles reduce headache)
• Manometer
• Four universal CSF sample containers (labelled 1-4). Usually yellow-topped.
• One glucose tube (fluoride oxalate tube, often grey)

10. Cerebrospinal Fluid Analysis
Figure (1): CSF Specimen collection

11. Cerebrospinal Fluid Analysis
CSF Specimen collection risks
Risks of lumbar puncture include:
• Bleeding into the spinal canal or around the brain (subdural hematomas).
• Discomfort during the test.
• Headache after the test that can last a few hours or days. It may be helpful to drink caffeinated beverages such
as coffee, tea or soda to help relieve the headache. If headaches last more than a few days (especially when you
sit, stand or walk) you might have a CSF-leak. You should talk to your physician if this occurs.
• Hypersensitivity (allergic) reaction to the anesthetic.
• Infection introduced by the needle going through the skin.
• Brain herniation may occur if this test is done on a person with a mass in the brain (such as a tumor or abscess).
This can result in brain damage or death. This test is not done if an exam or test reveals signs of a brain mass.
• Damage to the nerves in the spinal cord may occur, particularly if the person moves during the test.

12. Cerebrospinal Fluid Analysis
I. Chemical tests
1. Appearance
such as
Appearance
Normal CSF is completely clear and colorless; slight turbidity is most easily detected by visual
comparison with water.
Spontaneous clotting
Clotting occurs when there is excess fibrinogen in the specimen, usually associated with a very
high protein concentration. This finding occurs with tuberculous meningitis or with tumours of the
CNS.
Turbidity
Turbidity is usually due to infection or high CSF protein content. It may also occur after
hemorrhage.
Color
A bright red color may result from damage to a blood vessel during lumbar puncture (traumatic
tap) or a recent hemorrhage into the subarachnoid space.

13. Cerebrospinal Fluid Analysis
I. Chemical tests
2. Biochemical such as
Glucose test
pH
Electrolytes test
(Ca, K, Na, Mg…ect)
Protein test

14. Cerebrospinal Fluid Analysis
II. Microbial tests
This test is related to confirming the infection with one of the pathogens (bacteria or
viruses), depending on The type of symptoms shown by the pathogen. And used specific
microbial detection method on CSF sample. Microbes infected CSF Such as:
Bacteria
• Group B streptococci, Haemophilus influenza, Escherichia coli,
Streptococcus pneumoniae, Neisseria meningitides, Listeria
monocytogenes, Listeria monocytogenes.
Viruses
• Enteroviruses, Herpes simplex 1, Herpes simplex 2 (neonates), Varicella-zoster
virus, Epstein–Barr virus, Cytomegalovirus, West Nile virus, Tick-borne
encephalitis virus, Colorado tick fever virus, Measles virus.

15. Cerebrospinal Fluid Analysis
II. Microbial tests
Parasites
• Protozoa:- Trypanosomiasis, Malaria, Toxoplasma, Leishmaniasis, Amebiasis,
Microsporidiasis, Metazoa.
• Flatworms:- Schistosomiasis, Cysticercosis, Paragonimiasis, Hydatidosis,
Coenurosis, Sparganosis.
• Roundworms:-Gnathostomisasis, Angiostrongyliasis, Filariasis, Toxocariasis,
Strongyloidiasis.
Fungi
• Yeasts:- Candida, Cryptococcus neoformans.
• Molds:-Aspergillus, Mucor, Rhizopus, Rhzomucor, Absidia, Cunninghamella.
• Dimophic fungi:- Blastomyces dermatitidis, Histoplasma capsulatum, Coccidioides immitis.

16. Cerebrospinal Fluid Analysis
Normal Ranges (for some tests)
N. test Normal range
1. Appearance Clear
2. Specific gravity 1.006-1.007
3. Daily secretion 450-500 ml
4. pH 7.4
5. Total volume 100-150 ml
6. Microbes Nil
7. Lymphocytes <5/mm3
8. Protein 0.15-0.45g/L
9. Glucose 50-80mg/dL
10. Potassium 2.6-3.0 mmol/L
11. Calcium 1.0-1.40mmol/L
12 Magnesium 1.2-1.5 mmol/L

17. Cerebrospinal Fluid Analysis
Some Cases
A 17-year-old female student was admitted to hospital with fever, neck stiffness, headache,
photophobia and a purpuric rash. She had the following cerebrospinal
fluid (CSF) laboratory results:
CSF glucose 2.0 mmol/L (concomitant plasma glucose 5.6 mmol/L)
CSF protein 0.98 g/L(< 0.4 g/L)
Cerebrospinal fluid microscopy showed elevated leucocytes, and Gram staining showed gram-
negative Meningococcus.
DISCUSSION
A lumbar puncture to obtain CSF is potentially a dangerous, invasive
investigation. It carries the risk of cerebral herniation, bleeding and infection. In
this case, meningitis was suspected, which was confirmed by the CSF results.
Note the raised protein and low glucose concentrations relative to plasma due to
bacteria. The presence of bacteria is confirmed by microscopy. Meningococcus
can rapidly cause death, and is associated with massive haemorrhagic adrenal
destruction, as in Waterhouse–Friderichsen syndrome.
Case 1

18. Cerebrospinal Fluid Analysis
Some Cases
Neurosyphilis:
Treponema pallidum causes syphilis and, if the CNS is involved, neurosyphilis. Three stages
are usually seen in the course of the disease. In the early stage, the infection presents with
painless genital ulcers and lymphadenopathy. After 3–5 weeks of primary infection, some
patients progress to secondary syphilis, manifesting as meningitis. Meningitis in secondary
syphilis only occurs in 25% of syphilis infections and may present with headache, vomiting,
photophobia, and cranial nerve deficits (most commonly of the seventh and eighth nerves).
Late disease occurs > 10 weeks later and is also termed latent syphilis. This form can
ultimately lead to tertiary syphilis presenting as further neurologic dysfunction, including tabes
dorsalis, dementia, and general paresis.
Serologic testing with Venereal Disease Research Laboratory (VDRL) and rapid plasma reagin
is the gold standard for screening. Regarding the VDRL, although estimated specificity is high,
sensitivity is lower, which is a major limitation of the test. The method for both the serum and
CSF VDRL tests requires specialized glass plates and a light microscope. For CSF testing, the
cardiolipin-lecithin-cholesterol antigen is diluted and a smaller volume of the antigen
suspension is used compared to serum, adjusting for the much lower concentration of
immunoglobulin in CSF compared with blood
Case 2

19. References
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review". Journal of Neurology.
• Medlineplus network.
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features, complications, and outcome in adults with
pneumococcal meningitis: a prospective case series.
Lancet Neurol.
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• Sakushima K., Hayashino Y., Kawaguchi T.
Diagnostic accuracy of cerebrospinal fluid lactate
for differentiating bacterial meningitis from aseptic
meningitis: a meta-analysis.
• Walker M.D., Zunt J.R. Neuroparasitic infections:
cestodes, trematodes, and protozoans. Semin
Neurol.
• P.J., Donovan B. Clinical aspects of adult syphilis.
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• Clinical Biochemistry, Wiley Black. Well, 8 th
edition, 2010, chapter 19, page 274 -277 Clinical
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• Crook, Martin Andrew Clinical Biochemistry
and Metabolic Medicine. Chapter23, p332-334.

20. Thanks For All