Cerebrospinal fluid (CSF) is a clear fluid produced by the choroid plexuses in the brain ventricles and circulates through the ventricular system before reabsorbing into the venous blood. CSF acts as a cushion and protects the brain, and its analysis through lumbar puncture can help diagnose conditions like meningitis, tumors, and other brain and spinal disorders. The procedure involves inserting a needle between vertebrae to collect CSF for examination of properties like pressure, cells, proteins, and chemicals.

1. MINATI DAS
ASST. PROF.
KINS, KIIT UN

2. The cerebrospinal Fluid [CSF] is
a clear, colorless transparent,
tissue fluid present in the
cerebral ventricles, spinal canal,
and subarachnoid spaces.

4. CSF is largely formed by the choroid plexus of
the lateral ventricle and remainder in the third
and fourth ventricles.
About 30% of the CSF is also formed from the
ependymal cells lining the ventricles and other
brain capillaries.
The choroid plexus of the ventricles actively
secrete cerebrospinal fluid.
The choroid plexuses are highly vascular tufts

6. CSF is formed primarily by secretion and also by
filtration from the net works of capillaries and
ependymal cells in the ventricles called choroid
plexus.
Various components of the choroid plexus from a
blood-cerebrospinal fluid barrier that permits certain
substances to enter the fluid, but prohibits others.
Such a barrier protects the brain and spinal cord
from harmful substances.

7. The entire cerebral cavity enclosing
the brain and spinal cord has a
capacity of about 1600 to 1700
milliliters
About 150 milliliters of this capacity is
occupied by cerebrospinal fluid and
the remainder by the brain and cord.

8. Rate of formation:
About 20-25 ml/hour
550 ml/day in adults. Turns over 3.7
times a day
Total quantity: 150 ml:
30-40 ml within the ventricles
About 110-120 ml in the subarachnoid

9. CSF is formed at a rate of about 550 milliliters
each day,. About two thirds or more of this
fluid originates as secretion from the choroid
plexuses in the four ventricles, mainly in the
two lateral ventricles.
Additional small amount of fluid is secreted
by the ependymal surfaces of all the
ventricles and by the arachnoidal membranes
Small quantity comes from the brain itself
through the perivascular spaces that surround

10. Secretion by the Choroid Plexus. The choroid
plexus, is a cauliflower-like growth of blood
vessels covered by a thin layer of epithelial
cells.
Secretion of fluid by the choroid plexus
depends mainly on active transport of sodium
ions through the epithelial cells lining the
outside of the plexus.
The sodium ions in turn pull along large
amounts of chloride ions because the positive
charge of the sodium ion attracts the chloride
ion's negative charge. The two of these
together increase the quantity of osmotically

11. Secretion by the Choroid Plexus. The choroid plexus, is a cauliflower-like
growth of blood vessels covered by a thin layer of epithelial cells.
Secretion of fluid by the choroid plexus depends mainly on active
transport of sodium ions through the epithelial cells lining the outside of
the plexus.
The sodium ions in turn pull along large amounts of chloride ions
because the positive charge of the sodium ion attracts the chloride ion's
negative charge. The two of these together increase the quantity of
osmotically active sodium chloride in the cerebrospinal fluid, which then
causes almost immediate osmosis of water through the membrane, thus
providing the fluid secretion.

12. Less important transport processes move small amount of glucose into the
cerebrospinal fluid and both potassium and bicarbonate ions out of the cerebrospinal
fluid into the capillaries.
The resulting characteristics of the CSF are:
Osmotic pressure approximately equal to that of plasma sodium ion concentration
Approximately equal to that of plasma chloride ion
About 15 per cent greater than in plasma potassium ion approximately 40 per cent less
glucose

13. The arachnoidal villi are fingerlike inward projections of the arachnoidal
membrane through the walls into venous sinuses.
villi form arachnoidal granulations can protruding into the sinuses.
The endothelial cells covering the villi have vesicular passages directly
through the bodies of the cells large enough to allow relatively free flow of (1)
cerebrospinal fluid, (2) dissolved protein molecules, and (3) even particles as
large as red and white blood cells into the venous blood.

14. Proteins = 20-40
mg/100 ml
Glucose = 50-65 mg/100 ml
Cholesterol = 0.2 mg/100
ml
Na+ = 147 meq/Kg H2O
Ca+ = 2.3 meq/kg H2O
Urea = 12.0 mg/100 ml
Creatinine = 1.5 mg/100
ml
Lactic acid= 18.0 mg/100 ml

15. Nature:
Colour = Clear, transparent fluid
Specific gravity = 1.004-1.007
Reaction = Alkaline and does not
coagulate
Cells = 0-3/ cmm
Pressure = 60-150 mm of H2O
The pressure of CSF is increased in standing,
coughing, sneezing, crying, compression of
internal Jugular vein (Queckenstedt’s sign

16. Circulation: CSF is mainly formed in choroid pleaxus of the lateral
ventricle.
CSF passes from the lateral ventricle to the third ventricle through
the interventricular foramen (foramen of Monro).
From third ventricle it passes to the fourth ventricle through the
cerebrol aqueduct. The circulation is aided by the arterial
pulsations of the chroid plexuses.
From the fourth ventricle (CSF) passes to the sub arachnoid space
around the brain and spinal cord through the foramen of magendie
and foramina of luschka.

17. Lateral ventricle
Foramen of Monro [Interventricular foramen]
Third ventricle:
Subarachnoid space of Brain and Spinal cord
Fourth ventricle:
Cerebral aqueduct
Foramen of megendie and formen of luschka

18. Circulation: CSF slowly moves
cerebromedullary cistern and
pontine cisterns and flows
superiorly through the interval in
the tentorium cerebelli to reach the
inferior surface of the cerebrum. It
moves superiority over the lateral
aspect of each cerebrol
hemisphere.

19. A shock absorber
A mechanical buffer
Act as cushion between the brain and
cranium
Act as a reservoir and regulates the
contents of the cranium
Serves as a medium for nutritional
exchange in CNS
Transport hormones and hormone

20. Increased inflammatory cells [pleocytosis] may be caused by
infectious and noninfectious processes.
Polymorphonuclear pleocytosis indicates acute suppurative
meningitis.
Mononuclear cells are seen in viral infections (meningoencephalitis,
aseptic meningitis), syphilis, neuroborreliosis, tuberculous
meningitis, multiple sclerosis, brain abscess and brain tumors.

21. Increased protein: CSF protein may rise to 500 mg/dl in bacterial
meningitis.
A more moderate increase (150-200 mg/dl) occurs in inflammatory
diseases of meninges (meningitis, encephalitis), intracranial tumors,
subarachnoid hemorrhage, and cerebral infarction.
A more severe increase occurs in the Guillain-Barré syndrome and
acoustic and spinal schwannoma.

22. Multiple sclerosis: CSF protein is normal or mildly increased.
Increased IgG in CSF, but not in serum [IgG/albumin index normally
10:1].
90% of MS patients have oligoclonal IgG bands in the CSF.
Oligoclonal bands occur in the CSF only not in the serum.
The CSF in MS often contains myelin fragments and myelin basic
protein (MBP).
MBP can be detected by radioimmunoassay. MBP is not specific for MS.
It can appear in any condition causing brain necrosis, including infarcts.

23. Low glucose in CSF:
This condition is seen in suppurative tuberculosis
Fungal infections
Sarcoidosis
Meningeal dissemination of tumors.
Glucose is consumed by leukocytes and tumor cells.

24. Blood: Blood may be spilled into the CSF by accidental puncture of a
leptomeningeal vein during entry of the LP needle.
Such blood stains the fluid that is drawn initially and clears gradually.
If it does not clear, blood indicates subarachnoid hemorrhage.
Erythrocytes from subarachnoid hemorrhage are cleared in 3 to 7
days. A few neutrophils and mononuclear cells may also be present
as a result of meningeal irritation.

25. Xanthochromia [blonde color] of the CSF following subarachnoid
hemorrhage is due to oxyhemoglobin which appears in 4 to 6
hours and bilirubin which appears in two days.
Xanthochromia may also be seen with hemorrhagic infarcts, brain
tumors, and jaundice.

26. Tumor cells indicate dissemination of metastatic or primary brain
tumors in the subarachnoid space.
The most common among the latter is medulloblastoma.
They can be best detected by cytological examination.
A mononuclear inflammatory reaction is often seen in addition to the
tumor cells.

27. Infections: meningitis, encephalitis
Inflammatory conditions: Sarcoidosis, neuro syphilis, SLE
Infiltrstive conditions:Leukamia, lymphoma, carcinomatous - meningitis
Administration of drugs in CSF (Therapeutic aim)
Antibiotics: (In case of meningitis)
Antimitotics
Diagnostic aim: Myelography, Cisternography
Anaesthetics are also given through the lumbar Puncture.

28. Local skin infections over proposed puncture site (absolute
contraindication)
Raised intracranial pressure (ICP); exception is pseudotumor
cerebri
Suspected spinal cord mass or intracranial mass lesion (based on
lateralizing neurological findings or papilledema)
Uncontrolled bleeding diathesis
Spinal column deformities (may require fluoroscopic assistance)
Lack of patient cooperation

29. A lumbar puncture also called a spinal
tap is a procedure where a sample of
cerebrospinal fluid is taken for
examination.
CSF is mainly used to diagnose
meningitis [an infection of the
meninges].
It is also used to diagnose some other
conditions of the brain and spinal cord.

30.  Asked to sign a consent form
 Ask about taking any medicines
 Are allergic to any medicines
 Have / had any bleeding problems
 Ask about medications such as aspirin or warfarin
 Ask the female patient might be pregnant
 Empty the bladder before the procedure

31. 1. Material for sterile technique
[gloves and mask are necessary]
2. Spinal Needle, 20 and 22-gauge
3. Manometer
4. Three-way stopcock
5. Sterile drapes
6. 1% lidocaine without epinephrine in
a 5-cc syringe with a 22 and 25-
gauge needles
7. Material for skin sterilization
8. Adhesive dressing

32. Post lumbar puncture headache occurs
in 10% to 30% of patients within 1 to 3
days and lasts 2 to 7 days.
The pain is relieved by lying flat.
Treatment consists of bed rest and
fluid with simple analgesics.

33. Headache following a lumbar puncture is a
common and often debilitating syndrome.
Continued leakage of cerebrospinal fluid
from a puncture site decreases intracranial
pressure, which leads to traction on pain-
sensitive intracranial structures.
The headache is characteristically postural,
often associated with nausea and optic,
vestibular, or otic symptoms. Although
usually self-limited after a few days, severe
postural pain can incapacitate the patient.
Management is mainly symptomatic, but
definitive treatment with the epidural blood

34. Patient usually lie on a bed on side with
knees pulled up against the chest.
It may also done with sitting up and
leaning forward on some pillows. Sterilize
the area.
push a needle through the skin and tissues
between two vertebra into the space
around the spinal cord which is filled with
CSF.
CSF leaks back through the needle and is
collected in a sterile container.
As soon as the required amount of fluid is

35. Sent the sample to lab to be
examined under the microscope
to look for bacteria.
It is also 'cultured' for any
bacterial growth
The fluid can also be tested for
protein, sugar and other
chemicals if necessary.
Sometimes also measure the
pressure of the fluid. This is
done by attaching a special tube

44. Place the patient in the lateral
decubitus position lying on the edge of
the bed and facing away from operator.
Place the patient in a knee-chest
position with the neck flexed.
The patient's head should rest on a
pillow, so that the entire cranio-spinal
axis is parallel to the bed.
Sitting position is the second choice
because there may be a greater risk of

45. Find the posterior iliac crest and palpate the
L4 spinous process, and mark the spot with a
fingernail.
Prepare the skin by starting at the puncture
site.
Anesthetize the skin using the 1% lidocaine
in the 5 mL syringe with the 25-gauge
needle. Change to 22-gauge needle before
anesthetizing between the spinous process.

46. Hydrocephalus" means excess water in the
cranial vault.
This condition is frequently divided into
communicating hydrocephalus and
noncommunicating hydrocephalus.
In communicating hydrocephalus fluid flows
readily from the ventricular system into the
subarachnoid space,
in noncommunicating hydrocephalus fluid