ABOUT CSF
Cerebrospinal fluid (CSF)
was first examined in the
19th century using
primitive techniques (eg,
sharpened bird quills).
Indications of CSF examination
1. Bacterial, viral or fungal meningitis.
2. Encephalitis.
3. To investigate for Malignant
infiltrates eg acute leukemia,
lymphoma.
Indication of CSF examination
4. Disorders with local immunoglobulin
production in the CNS (multiple
sclerosis).
5. Subarachnoid hemorrhage.
6. Spinal canal blockage
Methods of CSF collection
 Lumber
 CSF
Puncture
also can be obtained from the
cisterna magna by a tap below the
external occipital protuberance.
Lumber Puncture: uses
Diagnostic and therapeutic uses
1. CSF examination [ diagnostic]
2. Therapeutic application of LP
A. For spinal anesthesia,
B. For introduction of radio opaque
contrast media (eg, myelography),
C. For injection of corticosteroids,
antibiotics, and chemotherapeutic
agents.
LP : Instruments and procedures
Which space you enter spinal canal ?
 LP
is performed in the interspaces
between the lumbar vertebrae,
usually at the L4-L5, or L3-L4 level.
Normal CSF values
Cell count:
<5 cells / cumm.
mononuclears;
Glucose:
60-70% of plasma levels
(usually) 2.8-4.4 mmol/L
Lactate:
1.2-2.8 mmol/L
Protein:
Full term neonate: 0.1-1.2
g/L
adult: 0.15-0.45 g/L
IgG/albumin ratio:
<0.2
CSF Pressure
 Normal
range is 80-180 mm H20
 May Increase in Brain Abscess and
encephalitis.
Interpretation: acute bacterial meningitis
(pyogenic).
CSF appearances
Cloudy
Cell count
Cell Type
Increased >1000
cell/cumm
Neutrophils
Protein
Normal-high
Sugar
Very much Reduced
Gram Stain
Often Positive
Culture
Often positive
Viral meningitis
CSF appearances
Clear
Cell count
Moderate Increase
Cell type
Lymphocyte
Protein
Increased
Sugar
Reduced
Culture
Negative
Fungal meningitis: Cryptococcus
neoformans Meningitis [ AIDS]
CSF appearances
Cell count
Cell type
Protein
Wright
Giemsa/India ink
Culture
Clear or cloudy
increased (10 -100)
Lymphocytes,
macrophage
Increased
Positive of fungus
Positive
Other facts
 In
traumatic Tap = RBCs may be
seen.
1.
2.
3.
Physical ( macroscopic
examination)
Chemical Analysis
Cytological Analysis
Value of macroscopic Examination
 Pseudomonal
meningitis may be
associated with bright green CSF.
 Red
Colour if contain RBC (
hemorrhage)
 Cob
web coagulum = Tuberculosis
Xanthochromia : Intracranial
Bleeding

The best way to
distinguish RBCs
related to intracranial
bleeding is
examination of the
centrifuged
supernatant CSF for
xanthochromia (yellow
color).
N
Xanthochromia
 Xanthochromia
can persist up to
several weeks following a
subarachnoid hemorrhage
Differential diagnosis : Xanthochromia
 Xanthochromia
can be produced by
spillover from a very high serum
bilirubin level (ie, >15 mg/dL).
Chemical Analysis
High Protein
 Demyelinating
 Postinfectious
Polyneuropathies
states
Low glucose
 Bacterial
 Tumor
infection
infiltration, and may be one of
the hallmarks of meningeal
carcinomatosis.
Cytological Analysis
Cytological examination
 Detection
of malignant cells:
Carcinoma, lymphoma or leukemia.
Oligoclonal bands; Increased
IgG/albumin ratio
1. Demyelinating disorders, esp-
Multiple Sclerosis.
2. Guillain-Barré syndrome,
Risk of LP
Post–spinal tap headache
 Nerve root trauma (eg, previous surgery
in the area, scar tissue)
 CNS infection (eg, immunocompromised
patients)
 Intraspinal hematoma (eg, patients on
anticoagulation therapy
 Tonsillar Herniation

LP and CSF
 In
summary, LP and CSF
examination, while their indications
have been reduced, remain
indispensable tools in the
armamentarium of neurologic
diagnosis.