CSF analysis provides important diagnostic information for conditions affecting the central nervous system. CSF is collected via lumbar puncture and analyzed for opening pressure, appearance, chemistry including glucose and proteins, cell counts and differentials, and microbiology. Abnormal findings can indicate infections like meningitis, tumors, hemorrhages, and other CNS pathologies. A thorough CSF analysis incorporating results from biochemistry, hematology, and microbiology departments helps reach the correct diagnosis and guides patient management.

1. CSF ANALYSIS

2. INTRODUCTION
It is clear,colourless fluid formed in the
ventricles of brain by choroid plexus.
Mainly it is an ultrafiltrate of plasma.
It is contained in the ventricles of brain,
Spinal canal and the subarachnoid space .

3. NORMAL COMPOSITION
• Appearance: clear & colourless
• Total volume: 100-150 ml
• Opening pressure: 60-180 mm of water
• Glucose: 45-80 mg/dl
• Proteins: 15-45 mg/dl
• Chloride: 120 -130 mEq/L
• Bilirubin: Absent
• Oligoclonal bands:Negative
• Cells :
Adults:0-5 cells(mainly lymphocytes)/mm3

4. Functions of CSF
1).Protection of brain & spinal cord thereby acting as
shock absorber.
2).Serve as medium between blood and brain for supply of
nutrients to and removal of waste products from the brain.
Collection of CSF
Collected by Lumbar puncture.

5. • Patient in lateral recumbent
position.
• Under aseptic precautions,
22g LP needle is introduced .
• Collected in 3 sterile tubes.

6. Collection of CSF
• LUMBAR PUNCTURE-
btwn L3-L4 vertebrae in adults
btwn L4-L5 vertebrae in children
• CISTERNAL PUNCTURE- done in both
• VENTRICULAR PUNCTURE
• SHUNT DRAINAGE

7. Tube 1: BioChemistry(glucose & protein)
Tube 2: Microbiology (gram’stain ,bacterial culture &
sensitivity and others)
Tube 3 : Clinical Pathology(TLC ,DLC & Visualisation of
Malignant cells & other cells)

8. INDICATIONS OF LUMBAR
PUNCTURE
Detection and diagnosis of Suspected Meningitis,Subarachnoid
Haemorrhage , Spinal cord tumor ,CNS Syphilis
Differential diagnosis of Cerebral Infarction vs Intracerebral
Haemorrhage
Introduction of Anaesthetics ,Radiographic contrast media or Drugs
To reduce CSF pressure in Benign Intracranial Hypertension
Removal of exudate or blood from Subarachnoid space.

9. COMPLICATIONS OF LUMBAR PUNCTURE
1).Post-puncture headache : most common side effect.
So small bore needle(22G) is used.
2).Introduction of infection in spinal canal
3).Subdural hematoma
4).Dry tap
5).Herniation of Brain

10. CONTRAINDICATIONS TO LUMBAR
PUNCTURE
A). Raised Intracranial pressure
B). Cardiorespiratory compromise
C). Bleeding diathesis
D).Local infection at the site.

11. EXAMINATION OF CSF
•CSF fluid is examined within 1 hour of collection
because A). Cells degenerate rapidly
B). Reduction of glucose due to Spontaneous
Glycolysis and usage by bacteria

12. 1). Opening pressure
During Lumbar Puncture,when CSF appears, manomete
Is attached to the spinal needle.
It is recorded with patient in lateral recumbent position

13. Increased CSF pressure
• Tense & anxious patient
• Intracranial mass lesion
• Meningitis
• Cerebral edema
• Subarachnoid
hemorrhage
Decreased CSF pressure
• Leakage of spinal fluid
following trauma or
lumbar puncture
• Complete spinal block
NOTE:If opening pressure is >200 mm ,not >1-2 ml of CSF
should be removed

14. 2). GROSS APPEARANCE OF CSF
A).TURBID CSF :
Leukocytes >200 cells/mm3
Red cells > 400 cells/mm3
Microorganisms like bacteria ,fungi or amoebae
Radiographic contrast media
Raised proteins
B). BLOOD MIXED CSF Traumatic Tap
Subarachnoid hemorrhage

15. CSF Finding Traumatic LP Subarachnoid hemorrhage
a).Gross appearance Blood more in initial tubes
as compared to later tubes
Blood clots on standing.
Blood uniform in all tubes
Blood does not clot on standing
b).Supernatant after
centrifugation
clear Pink or yellow
(Xanthochromia)
e).Microscopy Progressive decrease of
red cell counts in later tubes
Red cell counts uniform
In all tubes
c).CSF Pressure Normal Increased
d).CSF protein Normal Increased

17. C). XANTHOCHROMIA:
• Yellowish disolouration
of CSF
• Subarachnoid
hemorrhage
• Jaundice: serum
bilirubin >6mg/dl
• CSF protein >150mg/dl
D). OTHER ABNORMAL
COLOURS OF CSF
• Orange: high carotene
ingestion
• Brown:Meningeal
Metastatic Melanoma

18. E).CLOT FORMATION
• TB Meningitis
• (COB-WEB Formation)
• Purulent Meningitis
• Spinal block
• Traumatic LP
F).THICK VISCOUS CSF
Cryptococcal Meningitis
Meningeal Metastatic
Mucinous Adenocarcinoma
Severe Meningitis

19. 3). CHEMICAL EXAMINATION
a) Estimation of proteins :
• Normal levels : 15-45 mg/dl
Methods of estimation of proteins:-
•TURBIDIMETRIC METHOD
•PANDY’S TEST

20. CONDITIONS WITH ELEVATED CSF PROTEINS:
• MENINGITIS – Increased permeability of BBB
• SPINAL CORD TUMOR – Mechanical obstruction to CSF
circulation
• TRAUMATIC TAP & SUBARACHNOID HEMORRHAGE-
Hemorrhage in CSF
• MULTIPLE SCEROSIS & SSPE – Increased local production of
IgG

21. b) Estimation of CSF Glucose
• CSF Glucose is measured by Glucose Oxidase
method
Causes of decreased Glucose:
–Acute Bacterial Meningitis
–TB Meningitis
–Fungal Meningitis
–Hypoglycemia
• NOTE: CSF glucose normal in Viral Meningitis

22. c).Estimation of CSF ADA level
• Tuberculous : ADA >/- 10U/L
• Non-Tuberculous : ADA < 10U/L

23. d).Estimation of CSF Chloride
Normal levels –
Viral Meningitis
Viral Encephalitis
Poliomyelitis
Moderately Depressed level –Pyogenic Meningitis
Pronounced depression - TB Meningitis
Fungal Meningitis

24. 4).CELL COUNTS IN CSF
NOTE: It’s essential to do microscopic examination of all CSF samples
since WBC COUNT upto 200 cells/mm3 & RBC count upto 400 cells/mm3
are associated with clear appearance of CSF.
a).METHODS OF TLC:
Manual Method &
Automated Method
Manual Method
If CSF Clear – NO DILUENT used
If CSF turbid /cloudy –DILUENT used with 1:20 dilution
Diluting fluid used – TURK’S FLUID
WBC Pipette used

25. • For counting cells in CSF ,FUCHS-ROSENTHAL
chamber >> NEUBAUER chamber
In Fuchs –Rosenthal chamber
• Cells are counted in 5 large squares
• If CSF IS DILUTED – number of cells counted x
dilution factor(20)
• If CSF UNDILUTED – total cells counted in 5
squares(total WBC count)

26. In Neubauer’s chamber
• Cells are counted in 4 WBC squares
• If CSF IS DILUTED – number of cells counted x 50
• If CSF UNDILUTED – total cells counted in 4
squares(total WBC count)

27. b)DLC
• If CSF CLEAR – Few drops of sediment taken on the slide and it
is spread over it.
• If CSF TURBID – smear is made directly from the
uncentrifuged sample.
• Now smears are stained with Romanowsky & examined under
Microscope.
• In NORMAL ADULTS -DLC shows 70% Lymphocytes
30% Monocytes
• In CHILDREN shows -70% Monocytes

28. Causes of Pleocytosis
• Meningitis & other CNS
infections
• Intracranial Haemorrhage
• Meningeal Infiltration by
Malignancy
• Repeated Lumbar punctures
• Injection of foreign substances
into subarachnoid space.

30. Differential count

40. `
REACTIVE LYMPHOCYTES IN CSF

42. 5).Microbiological examination
a).Direct WET MOUNT OF CSF : Suspected cases of cryptococcal
infection,trypanosomiasis
and others.
OTHER TESTS are
b).GRAM’S STAIN
c).ZIEHL-NEELSEN STAIN
d).CULTURE for bacteria and Mycobacterium
e).PCR for Mycobacterium Tuberculosis and Viruses

43. Various CSF findings

44. SUMMARY
CSF Fluid which is collected in suspected CNS Pathology
via LUMBAR PUNCTURE, Processed and derived reports
from different departments thereby reaching the
appropriate Diagnosis and helping in the Management
of the CNS Disease.

45. CONCLUSION
Thus Analysis of CSF Fluid play a very important role in the
Diagnosis and Management of INFECTIOUS and
MALIGNANT Conditions of CNS