CSF/CNS Infections Flashcards
(28 cards)
Produced by-
Volume in
- Neonates-
- Adults-
Rate of Formation
Turnover
Choroid Plexus
- 10-60 mL
- 90-150 mL
500 mL/Day
Every 5-7 Hours
______ cells line the ventricles and play a role in transporting components of CSF into the ventricles
Ependymal Cells
Ependymal cells are a type of ____ cell
Glial
CSF fluid forms in two steps
1)
2)
1) Fenestration of capillaries delivers ultrafiltered plasma
2) Ependymal cells transport AA and protein components into vesicles
Capillary plasma ultrafiltrate is ____ blood/brain barrier
outside
These four substances are found in significantly lower concentrations in the CSF vs. Plasma
K+, Glucose, AA, and Proteins
______ move excess CSF from subarachnoid space to venous sinuses via transcytosis
Arachnoid Granulations
CSF is absorbed into the venous blood supply of the _____
Superior Sagital Sinus
Small Envaginations- Arachnoid ____
Large Envaginations- Arachnoid _____
- Villi
- Granulations
Three features of the blood/brain barrier
- Non-fenestrated (use tight junctions)
- Thick basement membrane
- Astrocyte endfeet surround the capillar
Cannot cross blood/brain barrier
Large, charged molecules
- Fibrinogen, Prealbumin
Drugs (some)
Readily cross Blood/Brain Barrier
Uncharged Molecules
Lipids
Oxygen
Caffeine, Nicotine, Ethanol, Heroin
Water
Lumbar Punctures should be performed at the level of
L3/L4 or L4/L5
Contraindications of LP
Increased Cranial Pressure bc this can cause cerebral herniation
Lumbar Puncture Complication
Headache in 10-30% of patients
Caused by decreased support of brain
LP Collection
20 mL, in 3-4 tubes
CNS Pathologies
Normal
Cloudy
Bloody
Orange/Brown
Viscous
Normal- Clear, Colorless, Water
Cloudy- High white count due to CNS infection
Bloody- Trauma from procedure or sub-arachnoid hemorrhage
Orange/Brown- Increased Carotene intake or metastic melanoma
Viscous- Metastic Mucinous Adenocarcinoma
Pleocytosis
Increased cell counts in CSF (indicated CNS infection)
Normal CSF Cell Counts
White
Red
1-5 Cells/microliter
0 cells per microliter
Normal CNS is mostly lymphocytes (40-80%), with few monocytes and neutrophils
Elevated Neutrophils indicate
Elevated Lymphocytes indicate
Elevated Neutrophils indicate Bacterial Infection
Elevated Lymphocytes indicate Viral Infection
CSF Glucuse usually goes ____
Caused by _____ not _____ themselves
CSF Glucuse usually goes down
Caused by increased brain anaerobic activity, not bacteria themselves
Three Reasons for increased CSF Proteins
Increased permeability at barriers (blood-brain-barrier, blood-CSF barrier)
Decreased reabsorbtion at arachnoid granules
increased production of immunoglobulins
Latex Agglutination Antibody Test
Looks for specific pathogens like strep pneumo or cryptococcus
- checks to see if CSF sample has antigen which clump onto antibodies
Bacterial Meningitis in Neonates
GEL
- G*roup B Strep
- E.*Coli
- L*isteria monocytogenes
