CSF

Question 1

1. What is the primary function of cerebrospinal fluid (CSF)?
   A. Transport oxygen
   B. Lubricate the joints
   C. Cushion the brain and spinal cord
   D. Aid in digestion

Answer 1

C. Cushion the brain and spinal cord

Question 2

2. Where is CSF primarily produced?
   A. Spinal cord
   B. Choroid plexus
   C. Cerebellum
   D. Medulla oblongata

Answer 2

B. Choroid plexus

Question 3

3. Which of the following is TRUE regarding the composition of CSF compared to plasma?
   A. CSF has more potassium and calcium
   B. CSF has less magnesium
   C. CSF has higher sodium and chloride
   D. CSF is an ultrafiltrate of plasma

Answer 3

C. CSF has higher sodium and chloride

Question 4

4. During a lumbar puncture in adults, which vertebral level is targeted?
   A. L1-L2
   B. L2-L3
   C. L3-L4
   D. L5-S1

Answer 4

C. L3-L4

Question 5

5. Which tube of CSF is used for cell count?
   A. Tube 1
   B. Tube 2
   C. Tube 3
   D. Tube 4

Answer 5

C. Tube 3

Question 6

6. What does xanthochromia in CSF indicate?
   A. Dehydration
   B. Bacterial meningitis
   C. Presence of bilirubin or oxyhemoglobin
   D. High CSF glucose

Answer 6

C. Presence of bilirubin or oxyhemoglobin

Question 7

7. Which WBC is predominantly elevated in bacterial meningitis?
   A. Lymphocytes
   B. Monocytes
   C. Neutrophils
   D. Eosinophils

Answer 7

C. Neutrophils

Question 8

8. In CSF, the presence of oligoclonal bands indicates:
   A. Viral infection
   B. Intracranial hemorrhage
   C. Tuberculosis
   D. Multiple sclerosis

Answer 8

D. Multiple sclerosis

Question 9

9. A CSF/serum albumin index > 100 suggests:
   A. Normal blood-brain barrier
   B. Minimal impairment
   C. Moderate impairment
   D. Complete breakdown of BBB

Answer 9

D. Complete breakdown of BBB

Question 10

10. Which CSF test is used to monitor demyelinating diseases like multiple sclerosis when oligoclonal bands are absent?
    A. CSF IgG
    B. CSF lactate
    C. Myelin basic protein
    D. CSF glucose

Answer 10

: C. Myelin basic protein

Question 11

11. How many tubes of CSF are usually collected during lumbar puncture?
    A. 1
    B. 2
    C. 3
    D. 5

Answer 11

C. 3

Question 12

12. What is indicated by a web-like pellicle formation in refrigerated CSF?
    A. Multiple sclerosis
    B. Fungal meningitis
    C. Tubercular meningitis
    D. Traumatic tap

Answer 12

C. Tubercular meningitis

Question 13

13. What differentiates a traumatic tap from an intracranial hemorrhage in CSF analysis?
    A. Color of CSF
    B. Presence of neutrophils
    C. Clot formation and uneven blood distribution
    D. Protein content

Answer 13

C. Clot formation and uneven blood distribution

Question 14

What does the presence of macrophages with hemosiderin or ingested RBCs in CSF indicate?
A. Viral meningitis
B. Traumatic tap
C. Intracranial hemorrhage
D. Tubercular meningitis

Answer 14

C. Intracranial hemorrhage

Question 15

15. What is the normal WBC count in adult CSF?
    A. 0-2 /µL
    B. 0-5 /µL
    C. 5-10 /µL
    D. 10-15 /µL

Answer 15

B. 0-5 /µL

Question 16

16. In children, what is the typical lymphocyte to monocyte ratio in CSF?
    A. 90:10
    B. 70:30
    C. 30:70
    D. 50:50

Answer 16

C. 30:70

Question 17

17. Which of the following is a hallmark finding in multiple sclerosis from CSF analysis?
    A. High glucose
    B. High lactate
    C. Oligoclonal bands in CSF but not in serum
    D. Increased eosinophils

Answer 17

C. Oligoclonal bands in CSF but not in serum

Question 18

18. Low CSF glucose (<40 mg/dL) may be caused by:
    A. Hyperglycemia
    B. Viral meningitis
    C. Bacterial or fungal meningitis
    D. Demyelinating diseases

Answer 18

C. Bacterial or fungal meningitis

Question 19

19. CSF lactate levels >35 mg/dL are most consistent with:
    A. Viral meningitis
    B. Multiple sclerosis
    C. Bacterial meningitis
    D. Traumatic tap

Answer 19

: C. Bacterial meningitis

Question 20

20. What is the characteristic appearance of Cryptococcus neoformans in India ink staining of CSF?
    A. Granules
    B. Reactive lymphocytes
    C. Starburst pattern
    D. Brown pigment

Answer 20

C. Starburst pattern

Question 21

21. What CSF protein is synthesized almost exclusively in the CNS and helps identify CSF origin in fluid leaks?
    A. Albumin
    B. Tau transferrin
    C. Transthyretin
    D. Immunoglobulin G

Answer 21

B. Tau transferrin

Question 22

22. A CSF IgG index greater than 0.70 typically indicates:
    A. Leukemia
    B. Bacterial meningitis
    C. Increased intrathecal production, often seen in multiple sclerosis
    D. Traumatic puncture

Answer 22

Answer: C. Increased intrathecal production, often seen in multiple sclerosis

Question 23

23. What is the normal range of CSF glucose in mg/dL?
    A. 20–40
    B. 40–60
    C. 50–80
    D. 80–100

Answer 23

C. 50–80

Question 24

24. Which of the following CSF findings is most characteristic of viral meningitis?
    A. High neutrophils
    B. High eosinophils
    C. Lymphocyte and monocyte predominance
    D. Very high lactate (>35 mg/dL)

Answer 24

C. Lymphocyte and monocyte predominance

Question 25

25. Which type of cells would most likely be present in CSF following a recent hemorrhage? A. Ependymal cells B. Eosinophils C. Erythrophagocytic macrophages D. Plasma cells

Answer 25

C. Erythrophagocytic macrophages

Question 26

26. What type of cells might be seen in CSF due to neurologic medical procedures and are considered non-pathologic? A. Choroidal, ependymal, and spindle-shaped cells B. Reactive lymphocytes C. Malignant lymphoblasts D. Hemosiderin-laden macrophages

Answer 26

A. Choroidal, ependymal, and spindle-shaped cells

Question 27

27. What kind of stain is typically used for CSF differential count? A. India ink B. Wright’s stain C. Gram stain D. Sudan III

Answer 27

B. Wright’s stain

Question 28

28. Increased CSF eosinophils may be found in cases of: A. Multiple sclerosis B. Parasites, fungi, or foreign materials C. Bacterial meningitis D. Viral meningitis

Answer 28

B. Parasites, fungi, or foreign materials

Question 29

29. What diagnostic test is helpful for differentiating hemorrhage from traumatic tap in a bloody CSF specimen? A. Gram stain B. Xanthochromia examination C. India ink test D. Total protein concentration

Answer 29

B. Xanthochromia examination

Question 30

30. What is the preferred method of concentrating CSF for microbiological and cytological analysis? A. Filtration B. Sedimentation C. Cytocentrifugation D. Evaporation

Answer 30

C. Cytocentrifugation

Question 31

31. Which of the following statements about CSF is FALSE? A. It is produced in the choroid plexus B. It contains more potassium and calcium than plasma C. It is not an ultrafiltrate of plasma D. It provides nutrients and removes waste from the CNS

Answer 31

B. It contains more potassium and calcium than plasma

Question 32

32. Which of the following is most likely seen in CSF during a traumatic tap? A. Even distribution of blood in all tubes B. No clot formation C. Heaviest blood concentration in Tube 1 D. Presence of hemosiderin-laden macrophages

Answer 32

Answer: C. Heaviest blood concentration in Tube 1

Question 33

33. What is the significance of detecting D-dimer in CSF using latex agglutination? A. Confirms bacterial meningitis B. Indicates recent traumatic puncture C. Confirms fibrin formation in hemorrhage D. Indicates viral meningitis

Answer 33

C. Confirms fibrin formation in hemorrhage

Question 34

34. What is the normal ratio of lymphocytes to monocytes in adult CSF? A. 50:50 B. 60:40 C. 70:30 D. 80:20

Answer 34

C. 70:30

Question 35

35. In a patient with multiple sclerosis, which combination of CSF results is most likely? A. Low glucose, high neutrophils, high lactate B. High lactate, xanthochromia, clots C. Oligoclonal bands, increased IgG, possibly elevated myelin basic protein D. Reactive eosinophils and fungal elements

Answer 35

Oligoclonal bands, increased IgG, possibly elevated myelin basic protein

Question 36

36. Which organism is classically associated with a starburst pattern in CSF Gram stain? A. Neisseria meningitidis B. Streptococcus pneumoniae C. Cryptococcus neoformans D. Listeria monocytogenes

Answer 36

C. Cryptococcus neoformans

Question 37

37. Which of the following findings is most characteristic of tubercular meningitis in CSF? A. Clear fluid with high neutrophils B. Web-like pellicle after refrigeration C. High glucose with lymphocytosis D. Oligoclonal bands

Answer 37

B. Web-like pellicle after refrigeration

Question 38

38. Which chemical test differentiates plasma contamination from increased blood-brain barrier permeability? A. CSF glucose B. CSF lactate C. CSF/serum albumin index D. Myelin basic protein

Answer 38

C. CSF/serum albumin index

Question 39

39. Which statement best describes CSF glucose levels in bacterial meningitis? A. Increased due to inflammation B. Remains normal C. Decreased due to glycolysis by neutrophils and bacteria D. Decreased due to increased sodium

Answer 39

C. Decreased due to glycolysis by neutrophils and bacteria

Question 40

40. Which cell type in CSF may indicate central nervous system involvement of leukemia? A. Plasma cells B. Ependymal cells C. Lymphoblasts and myeloblasts D. Reactive lymphocytes

Answer 40

C. Lymphoblasts and myeloblasts

Question 41

41. What is the typical total volume of CSF in adults? A. 10–60 mL B. 90–150 mL C. 150–250 mL D. 250–350 mL

Answer 41

Correct answer: B. 90–150 mL standard adult volume is 90–150 mL

Question 42

42. Which of the following is not a function of CSF? A. Supplying nutrients to nervous tissue B. Lubricating joints C. Removing metabolic wastes D. Cushioning the brain and spinal cord

Answer 42

B. Lubricating joints Correct!

Question 43

43. Xanthochromia in CSF is most commonly caused by: A. Albumin B. Bilirubin and oxyhemoglobin C. Magnesium D. Lactate

Answer 43

Correct answer: B. Bilirubin and oxyhemoglobin

Question 44

44. What is the normal WBC count in adult CSF? A. 0–2 /µL B. 0–5 /µL C. 5–10 /µL D. 10–15 /µL

Answer 44

Correct answer: B. 0–5 /µL

Question 45

45. In viral meningitis, the typical CSF WBC differential shows a predominance of: A. Neutrophils B. Eosinophils C. Lymphocytes and monocytes D. Plasma cells

Answer 45

Correct answer: C. Lymphocytes and monocytes

Question 46

46. Which CSF tube is used for microbiology? A. Tube 1 B. Tube 2 C. Tube 3 D. Tube 4

Answer 46

Correct answer: B. Tube 2 (Tube 1 is for chemistry/serology, Tube 2 for microbiology, and Tube 3 for cell count.)

Question 47

47. What protein is nearly exclusive to the CNS and used to confirm CSF origin in leaks? A. Albumin B. IgG C. Tau transferrin D. Myelin basic protein

Answer 47

Correct answer: C. Tau transferrin Correct!

Question 48

48. Oligoclonal bands found in CSF but not in serum are diagnostic of: A. Tuberculosis B. Cryptococcal meningitis C. Multiple sclerosis D. Bacterial meningitis

Answer 48

Correct answer: C. Multiple sclerosis

Question 49

49. CSF lactate levels >35 mg/dL most commonly indicate: A. Multiple sclerosis B. Viral meningitis C. Bacterial meningitis D. Chemical contamination

Answer 49

Correct answer: C. Bacterial meningitis

Question 50

50. A traumatic tap is best identified by: A. Brown-colored supernatant B. Equal blood in all tubes C. Clot formation and heaviest blood in Tube 1 D. Decreased CSF glucose

Answer 50

Correct answer: C. Clot formation and heaviest blood in Tube 1 Correct!

Question 51

51. In children, the normal lymphocyte to monocyte ratio in CSF is: A. 90:10 B. 70:30 C. 30:70 D. 50:50

Answer 51

Correct answer: C. 30:70

Question 52

52. Which CSF cell type is typically seen in parasitic or fungal infections? A. Neutrophils B. Eosinophils C. Lymphocytes D. Plasma cells

Answer 52

Correct answer: B. Eosinophils Eosinophils are classically seen in parasitic and fungal infections like Coccidioides immitis.

Question 53

53. The presence of reactive lymphocytes in CSF is associated with: A. Bacterial meningitis B. Fungal meningitis C. Viral infections D. Tubercular meningitis

Answer 53

Correct answer: C. Viral infections Reactive lymphocytes—with dark blue cytoplasm and clumped chromatin—are typical of viral infections

Question 54

54. A brown-colored CSF supernatant may suggest the presence of: A. Hematoidin B. Oxyhemoglobin C. Methemoglobin D. Carotene

Answer 54

Correct answer: C. Methemoglobin Brown color is due to methemoglobin, usually from an older hemorrhage.

Question 55

55. What stain is used in CSF to detect Cryptococcus neoformans with a "starburst" appearance? A. Gram stain B. India ink C. Wright’s stain D. Sudan III

Answer 55

Correct answer: B. India ink India ink reveals Cryptococcus with its classic starburst halo appearance

Question 56

56. What CSF abnormality is often present in patients with CNS tumors or metastases? A. High glucose B. Elevated eosinophils C. Decreased glucose D. Elevated tau protein

Answer 56

Correct answer: C. Decreased glucose CNS tumors often lower CSF glucose, not eosinophils.

Question 57

57. CSF myelin basic protein is most useful in monitoring which condition? A. Bacterial meningitis B. Multiple sclerosis C. Tubercular meningitis D. Leukemia

Answer 57

Correct answer: B. Multiple sclerosis Correct! MBP is released during demyelination.

Question 58

58. Which of the following CSF components is used to assess blood-brain barrier integrity? A. CSF IgG B. CSF albumin C. CSF lactate D. CSF glucose

Answer 58

Correct answer: B. CSF albumin The CSF/serum albumin index evaluates BBB integrity.

Question 59

59. CSF glucose is normally what percentage of the plasma glucose level? A. 20–30% B. 40–50% C. 60–70% D. 80–90%

Answer 59

Correct answer: C. 60–70% It’s typically about two-thirds of plasma glucose.

Question 60

60. In CSF cytology, the presence of lymphoblasts or myeloblasts suggests: A. Viral meningitis B. Fungal infection C. Leukemic infiltration D. Multiple sclerosis

Answer 60

Correct answer: C. Leukemic infiltration These immature bla

Question 61

61. What color change in centrifuged CSF supernatant is characteristic of xanthochromia? A. Cloudy white B. Pink to yellow C. Green D. Bright red

Answer 61

Correct answer: B. Pink to yellow Xanthochromia refers to a yellow to orange tinge, often due to bilirubin or oxyhemoglobin.

Question 62

62. The presence of hemosiderin-laden macrophages in CSF is a sign of: A. Viral meningitis B. Fungal infection C. Previous hemorrhage D. Multiple sclerosis

Answer 62

Correct answer: C. Previous hemorrhage These macrophages clean up blood products after intracranial hemorrhage.

Question 63

63. In which type of meningitis is CSF lactate rarely elevated above 25–30 mg/dL? A. Bacterial B. Tubercular C. Fungal D. Viral

Answer 63

Correct answer: D. Viral CSF lactate is usually normal in viral meningitis, and elevated in bacterial, fungal, or TB cases.

Question 64

64. Which is the preferred method for CSF cell counting? A. Hematocrit centrifuge B. Neubauer counting chamber C. Cytospin D. Filter paper method

Answer 64

Correct answer: B. Neubauer counting chamber Correct! Standard manual method for counting CSF cells.

Question 65

65. What reagent is used to lyse RBCs in CSF for WBC differential counting? A. 3% glacial acetic acid B. Sodium hydroxide C. Potassium chloride D. Formalin

Answer 65

Correct answer: A. 3% glacial acetic acid Correct!

Question 66

66. A decrease in CSF glucose can be due to all of the following except: A. Bacterial meningitis B. Viral meningitis C. Hypoglycemia D. Tumor infiltration

Answer 66

Correct answer: B. Viral meningitis Correct! Viral meningitis typically does not cause low glucose.

Question 67

67. Which is the hallmark CSF finding in multiple sclerosis? A. High lactate B. Xanthochromia C. Oligoclonal bands D. Decreased glucose

Answer 67

Correct answer: C. Oligoclonal bands Correct! Present in 95% of MS patients.

Question 68

68. Which cells are responsible for removing debris like RBCs from CSF? A. Lymphocytes B. Ependymal cells C. Macrophages D. Neutrophils

Answer 68

Correct answer: C. Macrophages Correct! These appear especially after hemorrhage or repeated taps.

Question 69

69. How soon should CSF WBC counts be performed after collection? A. Within 4 hours B. Within 2 hours C. Within 1 hour D. No time limit

Answer 69

Correct answer: C. Within 1 hour WBCs begin to lyse within 1 hour, so timing is critical.

Question 70

70. What test confirms the presence of fibrin degradation in hemorrhagic CSF? A. India ink B. D-dimer latex agglutination C. Wright’s stain D. Myelin basic protein test

Answer 70

Correct answer: B. D-dimer latex agglutination Correct!

Question 71

71. What is the main reason WBC counts in CSF should be performed promptly? A. Risk of microbial overgrowth B. WBCs lyse quickly C. Protein degradation D. Loss of glucose

Answer 71

Correct answer: B. WBCs lyse quickly Correct! WBCs start to break down within an hour.

Question 72

2. Which WBC in CSF may show pyknotic nuclei and mimic nucleated RBCs? A. Monocytes B. Reactive lymphocytes C. Degenerating neutrophils D. Eosinophils

Answer 72

Correct answer: C. Degenerating neutrophils Neutrophils with pyknotic nuclei can resemble NRBCs.

Question 73

3. In a traumatic tap, which of the following is typically absent? A. Clot formation B. Xanthochromia C. High RBCs in tube 1 D. Uneven blood distribution

Answer 73

Correct answer: B. Xanthochromia Correct! It usually takes 1–2 hours for RBCs to lyse and release pigments.

Question 74

4. Which of the following is not a normal CSF protein? A. Albumin B. Transthyretin C. Tau transferrin D. C-reactive protein

Answer 74

Correct answer: D. C-reactive protein Correct! CRP is an acute phase reactant and not a native CSF protein.

Question 75

5. Which method is best for visualizing motile Naegleria fowleri in CSF? A. Gram stain B. India ink C. Wright’s stain

Answer 75

Correct answer: D. Cytocentrifuge + Wright’s stain Motile trophozoites are best seen on cytocentrifuged smears stained with Wright’s.

Question 76

6. The presence of two transferrin bands on CSF protein electrophoresis indicates: A. Viral infection B. CNS malignancy C. Normal finding D. Contamination

Answer 76

Correct answer: C. Normal finding The second band is tau transferrin, a CNS-specific marker—normal in CSF.

Question 77

7. What is a distinguishing feature of choroidal and ependymal cells in CSF cytology? A. Brown pigment B. Round cells with coarse granules C. Seen after neurologic procedures D. Exclusively malignant

Answer 77

Correct answer: C. Seen after neurologic procedures Correct! These are non-pathologic cells that appear post-surgery or tap.

Question 78

8. Elevated CSF lactate suggests: A. Increased CNS oxygenation B. Viral etiology C. Anaerobic metabolism in CNS D. Normal blood-brain barrier

Answer 78

Correct answer: C. Anaerobic metabolism in CNS Lactate rises due to hypoxia/anaerobic metabolism—often in bacterial infections.

Question 79

9. What protein is used to calculate the CSF/serum albumin index? A. IgG B. Myelin basic protein C. Albumin D. Transthyretin

Answer 79

Correct answer: C. Albumin The albumin index assesses BBB permeability.

Question 80

10. Which cell type is typically not present in normal adult CSF? A. Monocytes B. Lymphocytes C. Eosinophils D. Occasional neutrophils

Answer 80

Correct answer: C. Eosinophils Correct! Eosinophils are abnormal and seen in parasites, fungi, or shunt reactions.