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Question 1

Functions of Cerebrospinal Fluid (CSF)

Answer 1

• Protects and lubricates the brain.
• Modulates pressure changes.
• Provides nutrients & removes wastes.
• Act as a chemical buffer to maintain constant ionic environment.
• Act as a transport medium for nutrients and metabolites, endocrine substances and neurotransmitters.

Question 2

Volume of CSF

Answer 2

Volume: 100-200 ml average 150ml.

Question 3

CSF Sample Collection

Answer 3

• Lumbar puncture or spinal tap, Interspace of vertebrae L3-L4 or L4-L5 is the most common procedure of collecting CSF

• Cisternal tap also used but less common.

• Patient positioned on side with knees and chin tucking towards abdomen.
• Occasionally can be done in sitting position bending forward.

Question 4

CSF Sample Collection • ……….ml can be collected

Answer 4

• 10-20 ml can be collected as required.

Question 5

• If CSF fluid cannot be analyzed for glucose within ½ hour of withdrawal, the CSF should be collected in a bottle containing……… …………?

Answer 5

sodium
fluoride

Question 6

CSF Sample Collection

Answer 6

1. Biochemistry ions, glucose, lactose, proteins.
2. Cytology: count of RBC, WBC & differential count.
3. Bacteriology: standard culture and/or PCR.
4. 1 backup sample stored at 4°C.
   jamawims

Question 7

Normal CSF
Color and appearance

Answer 7

clear and colorless, no coagulum or sediment on
standing.

Question 8

CSF cells

Answer 8

CSF does not contain cells (normal: up to 4 WBC/l)

Question 9

CSFglobulins

Answer 9

Not increased pandy’s test
Nonne- Apelt tests negative

Question 10

Abnormalities In Appearance of CSF
I. Color:

Answer 10

Presence of blood is the main cause of an abnormal color. It may be due to:
a. Trauma: Some blood may be introduced to CSF.
b. Pathological: Hemorrhagic fluid obtained in subarachnoid hemorrhage, hemorrhage into the ventricles & following neurosurgical operations.

Xanthochromia: This is yellow coloration of CSF due to:
a. Hb
b. Other pigments, usually bilirubin/or carotenoids.
o High CSF bilirubin in:
- Cholestatic jaundice.
- Icterus neonatorum Xanthochromia may be caused by all of the following: a. Pus. b. Previous traumatic tap. c. Recent infarct.

Question 11

Abnormalities In Appearance of II. Turbidity

Answer 11

marked ↑ in number of cells or when organisms are present. So, turbidity is found in meningitis specially in coccal type.

CSF in viral meningitis or tubercular meningitis → usually not turbid, (cell response in these cases are lymphocytic).

Question 12

Biochemical Changes In CSF pH Value of CSF : →…….

It depends mainly on the….

Answer 12

pH Value of CSF : → about 7.3

It depends mainly on the pCO 2 content.

While CO2 equilibrates between plasma and CSF relatively quickly, changes in HCO3- concentration are slower.

Question 13

Normal Glucose in CSF: depends on blood glucose, and normally stays at about …… % of its blood concentration because of incomplete
penetration of BBB.
Level varies from …….-……. mg/dL,

Answer 13

60

50-80 mg/dL, though a range of 45-100 is often

Question 14

Causes of Decreased CSF Glucose Level:

Answer 14

• Coccal meningitis: due to meningococci, staphylococci, pneumococci • glucose often disappears completely in CSF & become totally absent.

Tuberculous meningitis: Glucose ↓ but it is rarely absent completely, usually it varies from 10 to 40 mg/dL.

• In viral meningitis: often normal, but it is occasionally as low as 20 mg/dL

• In neurosyphilis: It is almost always within normal limits.

• In cryptococcal meningitis: Usually low values are seen.

• In hypoglycemia due to various causes.

• Carcinomatous infiltration of meninges and leukemic cells infiltrations in leukemias → ↓ CSF glucose.

Question 15

Normal Glucose of CSF:

Answer 15

Normal Glucose of CSF:
• In the majority of cases of other CNS diseases as in neurosyphilis.

Question 16

Increase in CSF Glucose Level:

Answer 16

• Considerable ↑ are seen in diabetic hyperglycemia but the CSF value remains < in the blood.

• Small ↑ in some cases of encephalitis, poliomyelitis, and cerebral abscess, (in some cases, values 150-180 mg/dL), but this is of little
diagnostic value.

Question 17

Urea:
Urea concentration in CSF is ………. to that of plasma,

Answer 17

similar

When there is nitrogen retention due to chronic renal failure the CSF urea concentration ↑ in parallel with the plasma urea.

Question 18

Estimation of CSF Proteins: Normal values:

Answer 18

Normal values: Proteins of normal lumbar CSF range is 15-45 mg/100 ml, most containing 20-40 mg/dL.
Protein content is almost albumin, with small amounts of globulins.

Question 19

Increase in CSF Proteins:

Answer 19

The ↑ in proteins caused by the breakdown of “blood-CSF & brain-CSF barriers”, that may be due to:
• An inflammatory reaction, - Obstruction.

• Indicates hemorrhage.
• Acute meningitis
• Marked ↑ in polyneuritis & tumors (as meningioma).
• In chronic conditions: as multiple sclerosis and general paresis→ slight ↑ in CSF protein, mainly due to ↑ in γ-globulins.

Very high ↑ to 10g/L in CSF below a spinal block– due to albumin leaked from plasma.
• A spinal block is usually due to a tumor & arachnoid adhesions in pyogenic meningitis.

Following marked changes in plasma proteins as occurs in multiple myelo- matosis.

General toxic states as uremia or after a myelogram.

Question 20

Froin’s syndrome: It is the “triad” of CS fluid findings that includes:

Answer 20

Froin’s syndrome: It is the “triad” of CS fluid findings that includes:
o Protein concentration 500 mg% or higher,
o Xanthochromia,
o Spontaneous clotting.

Question 21

• ↑ In both cells and proteins occur in:

Answer 21

• inflammatory lesions,
• all types of meningitis,
• poliomyelitis,
• general paralysis of insane & tabes dorsalis (in late stages and
  untreated syphilis respectively)

Question 22

Small ↑ in cells may occur in

Answer 22

Small ↑ in cells may occur in polyneuritis and in multiple sclerosis,
not always with a protein ↑ except later on.

Question 23

↑ in protein compared to cells albumino-
cytologic dissociation most commonly found in

Answer 23

tumors particularly spinal ones.
• After cerebral arteriosclerosis and cerebral infarction, and in acute
post-infective polyneuritis (Guillain-Barre Syndrome).

Question 24

……………… given intrathecally shortly before CSF sampling →
interfere with routine method of copper reduction used.

Answer 24

Streptomycin

Question 25

coccal meningitis, there is an ↑

Answer 25

IgM

Question 26

CSF contains proteins derived from brain tissue and spinal
cord, then mainly the local

Answer 26

immunoglobulins are ↑.

Question 27

changes of……….,
which ↑ is in multiple sclerosis and in neurosyphilis.

Answer 27

γ-globulins