CSF

Question 1

Why is CSF volume important

Answer 1

If too much: hydrocephalus
BBB compromised, intracranial pressure

Question 2

CNS membranes

3

Answer 2

Dura mater (outermost)
Arachnoid
[CSF here]
Pia mater (innermost)

Question 3

CSF production

Answer 3

Brain secretions and plasma filtrate
- One way reabsorption valves for waste

Selective filtration of plasma so chemical composition is different from ultrafiltrate plasma

Question 4

Fluid output rate

Answer 4

20 ml/hr

Question 5

Blood brain barrier

Answer 5

Tight capillary endothelium that creates CSF
- substances pass through the cells, atransport/diffusion

Question 6

CSF volume for ages

Answer 6

Adults: 90-150 mls
Infants: 10-60 mls

Question 7

CSF components compared to plasma

Answer 7

CSF has more: Na, Mg, Cl
less: glucose, K, bicarb, protein

Question 8

CSF collection procedure

age, volume, pressure

Answer 8

Adults: between L3 L4
Children: between L4 L5

10-20 mls removed

50-180 mmHg pressure normal

Question 9

Collection tube order

and why

Answer 9

• 1: chem/serology because least affected by blood or bacteria introduced as a result of the procedure
• 2: micro
• 3: heme/cell count

Question 10

Collection tube storage

Answer 10

• Heme: fridge up to 4 hrs
• Micro: room temp
• Chem/sero: frozen

Question 11

CSF that is colored: term

Answer 11

Xanthochromic

Question 12

Pleocytosis

Answer 12

Increased wbcs and rbcs: cloudy specimen

Question 13

Clotting in CSF

Answer 13

ALWAYS ABNORMAL
- fibrinogen and plasma proteins
- can be from pellicle formation after fridge
- common in traumatic taps

Question 14

Proteins in CSF

Answer 14

15-45 mg/dl can be normal, prealbumin, albumin, transferrin
Increased: infections, tumors, hemorr, cns disorders
Decreased: dural tear, cranial pressure

Question 15

Reasons for proteinsin CSF and difference

Answer 15

Impaired BBB: most cases, albumin
Increased synthesis: less common, IgG

Question 16

Normal ratio for albumin

Answer 16

<9

Question 17

Normal ratio for IgG

Answer 17

<8

Question 18

IgG index formula

Answer 18

(IgG CSF/IgG serum) x (albumin serum/CSF albumin)

Normal: 0.3 - 0.7
- Increased: MS, neuro probs
- Decreased: BBB bad

Question 19

BBB damage vs CNS synthesis in relation ot the ratios

Answer 19

BBB damage: increased albumin AND IgG ratio, decreased IgG index

CNS synthesis: normal albumin, IgG ratio and IgG index increased

Question 20

Glucose in CSF

Answer 20

ratio compared to serum is 0.6 normal
Decrease: increased glycolysis, some cancers, transport issues
Increase: bloody tap, hyperglycemia

Question 21

Lactate in csf

Answer 21

Normal: 11-22 mg/dk

Increase: tissue hypoxia

Viral: <30 mg/dl

Bacteria, other: >35 mg/dl]

Question 22

Lactate dehydrogenase

Answer 22

Supports meningitis diagnosis
- LD 4, 5 in granulocytes = bacterial
- LD 2, 3 in lymphs = viral

Question 23

Microbiological examination

Answer 23

gram stain, or acid fast
culture, always blood culture

• use sediment for smears and cultures

Question 24

Cells in CSF amount with age

Answer 24

Decreases with age
Younger = more cells in CSF

Question 25

Lymphs to monos ratio

Answer 25

70:30

Question 26

WBC reference range %s ## Footnote adult vs infants

Answer 26

**Adults:** 30-96% lymphs, 15-56% monos, 0-7% PMNs **Infants:** higher monos, lower lymphs

Question 27

Normal cells in CSF

Answer 27

Lymphs: dominating - Increased: non bacterial infections, listeria, degenerative Monos: not dominating

Question 28

Macrophages in CSF

Answer 28

Not normal - Hemorrhage or bleed, inclusions **< 12 hrs:** RBCs, PMNs, lymphs, monos, macros **12-48 hrs:** lymphs, macros, erythrophages **2-4 days:** erythrophages, vacuolated macros, siderophages **1-8 weeks:** siderophages, macrophages w/ hematin

Question 29

Other cells in CSF

Answer 29

**Lining cells** - Ependymal - Choroid plexus - PAM cells More likely in kids, abnormal # after surgery, trauma **Bone marrow cells** **Chondrocytes** cartilage from vertebral disk **NRBCs, SECs**

Question 30

Bacterial vs viral meningitis ## Footnote glucose, lactate, cell count, wbcs

Answer 30

**Bacterial** - decreased <0.60 glucose - increased >35 mg/dl lactate - very increased >50,000/ul - PMNs dominate **Viral** - normal to decreased glucose - slight increase lactate 23-30 mg/dl - increased but <50,000/ul cells - lymphs dominate

Question 31

Multiple sclerosis

Answer 31

Increased CSF IgG index Oligoclonal bands Plasma cells