Term
| Anatomy and Physiology of CSF |
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Definition
• Produced by choroid plexus and ultrafiltration
• Approximately 500 ml/day
• Bathes CNS while it collects waste and provides nutrients
• Total volumes
- Adults: 140–170 ml
- Children 10–60 ml |
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Term
| Collection and Processing of CSF |
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Definition
• Lumbar puncture, cisternal puncture, lateral cervical puncture, shunts and cannulas
• Opening pressure 90–180 mm H2O
• Approximately 15–20 cc fluid collected
• Process within 1 hour without refrigeration—STAT
• Three-tube set up
- Tube 1—chemistry and immunology
- Tube 2—microbiology
- Tube 3—cell count, differential, cytology |
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Term
| Why microbiology tube second? |
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Definition
Tube two is microbiology tests. And the reason we picked tube two is because if there's going to be any contamination of a sample due to the needle stick, we can collect that in tube one. So tube two, if it's going to be a sterile spinal fluid, which it should be, if there's any abnormalities, bacterial wise or whatever, we should pick those up in two.
Tube three is the cell count, differential, and looking for cytology. And the reason we do tube three for the cell count is because by then if there was any traumatic tap, and that was blood in the spinal fluid, that should have cleared by now. |
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Term
| Indications for lumbar puncture |
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Definition
• Meningeal infection
• Subarachnoid hemorrhage (SAH)
• CNS malignancy
• Demyelinating diseases |
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Term
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Definition
| Now the LP procedure is not a very complicated procedure. But you are injecting a needle into the person's spinal column and collecting fluid. Now we're going to give you a link that you can go watch a video of this procedure brought to you by the New England Journal of Medicine. They have a series of videos that we can have you watch. And the one I want you to look at, and we'll provide you the link as I said, is on the lumbar puncture. |
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Term
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Definition
• Normal CSF is clear, colorless
• Viscosity equal to water
• Clot seen in traumatic tap, not SAH
• Viscous CSF with increased protein exudate
• Turbidity
- WBC > 200 cells/L
- RBC > 400 cells/L
- Microorganisms, increased protein |
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Term
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Definition
- Required
• Opening CSF pressure
• Total cell count and differential • Glucose (CSF/plasma ratio)
• Protein
- Optional
• Cultures, Gram stain, antigens, cytology • Protein electrophoresis, VDRL, D-dimers |
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Term
| Differential Dx of Bloody CSF |
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Definition
• Traumatic tap—blood clears between tubes
• Xanthochromia—pink tinge, RBCs
• SAH—blood does not clear or clot |
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Term
|
Definition
• Pink, orange, or yellow discoloration
• RBC lysis or hemoglobin breakdown
• May be seen with hours of LP
• Peak intensity at 24–36 hours
• RBC > 6000/μL (SAH, ICH, infarct, traumatic)
• Oxyhemoglobin, bilirubin, increased protein
• Carotinoids, melanin, rifampin therapy |
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Term
| types of meningitis and lab results |
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Definition
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Term
| Increased Neutrophils in CSF |
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Definition
• Meningitis (bacterial, early TB, fungal)
• Following seizures
• Following CNS hemorrhage
• Following CNS infarct
• Reaction to repeated LP
• Foreign materials
• Metastatic tumor |
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Term
| Increased Lymphocytes in CSF |
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Definition
• Meningitis (viral [aseptic], L. monocytogenes)
• Parasitic infection
- May also note eosinophils
• Degenerative disorders
- SSPE, MS, encephalopathy
due to drugs, GBS
• Other inflammatory conditions
- Sarcoidosis, polyneuritis |
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Term
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Definition
- Nonspecific marker of disease
- Increased blood-CSF permeability
• Meningitis (bacterial, fungal, TB)
• Hemorrhage (SAH, ICH)
• Endocrine disorders
• Mechanical obstruction (tumor, disc, abscess) • Neurosyphilis, MS, SSPE, GBS, CVD |
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Term
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Definition
• Reflects serum hyperglycemia
• CSF glucose is two-thirds of serum glucose
• CSF glucose does not usually rise above 300 mg/dl |
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Term
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Definition
• Hypoglycemia
• Granulomatous process
- Bacterial tuberculosis
- Sarcoidosis
• Chemical meningitis
• Bacterial meningitis
• Fungal meningitis
• SAH
• Neoplasm
• Certain CNS viral infections
- Herpes simplex virus
- Mumps |
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Term
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Definition
• Darkfield microscopy for spirochetes • CSF FTA-ABS 100% sensitive
- Negative test rules out diagnosis
• VDRL nearly 100% specific
•-Positive test rules in neurosyphilis
• RPR unsuitable for CSF |
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Term
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Definition
• India ink for cryptococcal capsular halos
- 50% sensitivity
• LA and CF antibodies now available
- Sensitivity as high as 96% |
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Term
| Primary Amebic Meningoencephalitis (PAM) |
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Definition
• Rare disease caused by free-living amoeba Naegleria fowleri or Acanthamoeba species
• Motile Naegleria trophozoites may be seen with light microscopy
• Acridine orange stain can differentiate amoeba (brick red) from leukocytes (bright green) |
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Term
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Definition
- Viral (most common)
• Herpes
• Enterovirus • Coxsackie virus • Echovirus
• Mumps virus (rare now)
- Leptospiral
• Spirochete infection
- Drugs
• NSAIDs, sulfonamides, certain solid organ transplant agents |
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Term
| Meningitis Bacterial Etiologies |
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Definition
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