2. ANATOMY AND PHYSIOLOGY
• Cerebrospinal fluid (CSF) is present within the subarachnoid
space surrounding the brain in the skull and the spinal cord
in the spinal column.
• It is a clear , colorless , transparent fluid present in the
cerebral ventricles, spinal canal and subarachnoid spaces.
• Formed mainly by choroid plexus
3. Function of CSF
• _It's main function is to protect the brain and the spinal cord
from injury by acting as a fluid cushion.
• It is the medium through which nutrients and the waste
products are transported between brain/spinal
cord and the blood.
4. Formation of CSF
• CSF is derived by ultra filtration of plasma and by secretion
through the choroid plexus located in the ventricles of the
brain.
• Reabsorbtion of CSF occurs at the arachnoid villi which
projects in the venous sinuses in the duramater.
• CSF is produce at the rate of 500 mL/day.
• Rate of formation – about 20ml/hr
5. Circulation of csf
• Lateral ventricle
foramen of monro
third ventricle
cerebral acqueduct
fourth ventricle
foramen of Luschka
subarachnoid space of brain and
spinal cord
6. Indication of csf examination
Diagnosis of suspected cases-
1) CNS Infections: Meningitis, Encephalitis
2) Inflammatory conditions: multiple sclerosis, Guillain bare
syndrome.
3) Infiltrative conditions: Leukemia, lymphoma
4) Administration of drug in CSF (therapeutic aim):
Antibiotics
Anticancer drugs
Anesthetic drugs
5)Introduction of radiographic contrast media for
myelograpghy.
7. Complications of Lumbar puncture
A)Post puncture headache (d/t leakage of csf)
B)Introduction of infection if aseptic precautions.
C)Herniation of brain
D) Dry tap (failure to obtain csf)
8. Contraindication of lumbar puncture
• Patient does not give consent.
• Raised intracranial pressure
• Skin infection at puncture.
• Coagulpathy/ bleeding disorder
• Any mass lesion at or above lumbar puncture site.
13. • After collection csf sample should be sent to lab
immediately, and examined without delay.
- Cells disintegrate rapidly
- Reduction of glucose (Glycolysis)
• Examined within 1 hour of collection .
• Specimen for bacterial culture should not be refrigerated,
because fastidious organism do not survive in cold
temperature.
23. DIFFERENTIAL CELL COUNT
• Preparation by centrifuge
• Other technique- cytocentrifuge, sedimentation , filtration
• Normally Lymphocytes and monocytes are present in small
numbers in a ratio of 70:30
• . Monocytes are more in number in neonates and children.
