Chapter 10 - Cerebrospinal Fluid PDF

6/26/2024 CEREBROSPINAL FLUID Chapter 10 PREAMBLE PowerPoints are a general overview and are provided to help students take notes over the video lecture ONLY. PowerPoints DO NOT cover the details needed for the Unit exam Each student is responsible for READING the...

6/26/2024 CEREBROSPINAL FLUID Chapter 10 PREAMBLE PowerPoints are a general overview and are provided to help students take notes over the video lecture ONLY. PowerPoints DO NOT cover the details needed for the Unit exam Each student is responsible for READING the TEXTBOOK for details to answer the UNIT OBJECTIVES Unit Objectives are your study guide (not this PowerPoint) Test questions cover the details of UNIT OBJECTIVES found only in your Textbook! 1  6/26/2024 C S F F O R M AT I O N AND PHYSIOLOGY Cerebrospinal fluid (CSF)  Supply nutrients to the nervous tissue  Removes metabolic waste Lining of the brain and spinal cord is made up meninges (3 layers)  Maintains intracranial pressure  Cushions the brain & spinal cord Dura mater (hard layer that lines the skull & spinal column) Arachnoid (spider web) filamentous inner membrane Pia mater – (gentle) thin lining membrane on the brain & spinal cord CSF is produced by the choroid plexuses (2 lumen ventricles and 3rd & 4th ventricles) capillary network of filtration between the blood plasma and CSF BLOOD-BRAIN BARRIER (tight fitting endothelial cells) 20 ml of CSF is produced every hour- fluid goes to the subarachnoid space Normal volume is 90 – 150 ml (neonates 10 – 60 ml C S F F O R M AT I O N AND PHYSIOLOGY The endothelial cells allow soluble nutrients and waste to exchanged between the plasma and tissues. The blood-brain barrier protects the brain. The valves act in a one-way response. Disruption of the barrier by disease (MENEGITIS) infection multiple sclerosis Allows protein, glucose and leukocytes (WBC) into the CSF 2  6/26/2024 SPECIMEN COLLECTION & HANDLING CSF collection = lumbar puncture between After the needle is in place, the opening pressure is recorded in 3rd & 4th vertebra or 5th & 6th vertebra patient chart by the trained physician performing the lumbar puncture. Elevated pressure requires the fluid to be removed slowly. Specimens are collected sterilely in 4 tubes 1. Chemistry and serology test – may be frozen 2. Microbiology – room temperature 3. Cell count – hematology – may refrigerate up to 4 hrs 4. Might be used for microbiology or for extra test CSF is STAT APPEARANCE OF CSF Report color and clarity Colorless / clear Cloudy Turbid ↑protein, lipids or WBCs Milky Xanthochromic = pink, orange, yellow = Due to RBCs breakdown, ↑ bilirubin Bloody (red) REFER to table 10-1 3  6/26/2024 BLOOD IN CSF Even or uneven distribution of blood Bloody = intracranial hemorrhage = even Uneven = traumatic tap highest concentration in tube 1 and diminish to tube 2, 3 If blood is present, there is a chance of clot formation. If a clot is present them fibrinogen (factor 1 ) is present. Fibrinogen should not be able to past the barrier therefore CSF should not clot Xanthochromic – is an indication of old blood (longer than a traumatic tap) Red = traumatic tap orange / yellow = old blood CELL COUNTS Cell counts leukocyte (WBC) or nucleated cells Normal adult values for CSF = 0 to 5 WBCs/ul children’s can be higher neonates = 30 mononuclear cells 200 wbc/ul and 400 rbc /ul - can still be clear Red blood cells Normal value for RBCs = 0, most red cells are due to the tap Automation is becoming more frequent for counting for standardization, precision and faster TAT Traditional way = Neubauer chamber and an equation Number of cells counted x dilution Number of squares counted x volume of 1 square = cells/ul 4  6/26/2024 CELL COUNTS Depending on the number of cells in the CSF W W Look on 10 x to see the distribution If few number of cells are present, count all 9 squares Sometimes, the WBC may be less than RBC and you may count in different areas W Stain can be used to help distinguish the WBCS Glacial acetic acid will lysis the RBCs to allow better visibility of the WBCs W DIFFERENTIAL COUNT After the total WBC is calculate, the cells need differentiated. Stained smear or cytospin slide The distribution of the cell should Cytocentrifuge be a monolayer. Forces cells onto a slide in a monolayer Filter paper absorbs moisture Some labs report only 0.1 mL CSF to 1 drop 30% albumin mononuclear and polynuclear Albumin increases the cell yield and decreases the cellular other report a 5-part differential distortion Table 10-2 gives recommendation to how many cells to count based off the chamber count 5  6/26/2024 DIFFERENTIAL COUNT Pleocytosis = increase of normal cells = ABNORMAL Normally Present – lymphocytes & monocytes Increased cells help diagnosis the meningitis ↑ neutrophils = Bacterial ↑ lymphocytes and monocytes = viral, tubercular, fungal or parasitic Refer to table 10-3 P O LY N U C L E A R C E L L S EOSINOPHIL NEUTROPHILS Parasitic infection Bacterial infections Fungal infection Early onset of viral, fungal, tubercular, parasitic Introduction of foreign material = allergic The appearance of a neutrophil reaction Cytoplasm vacuolated Granules could be lost may see phagocytized bacterial pyknotic = degenerated cells 6  6/26/2024 MONONUCLEAR CELLS LY M P H O C Y T E S MONOCYTES / MACROPHAGES Normal to see in low numbers Usually counted together Viral, tubercular, fungal meningitis Monocytes = blood Reactive lymphocytes Macrophages / histocytes = tissue Dark blue cytoplasm Viral, tubercular, fungal meningitis clumped chromatin plasma cell HIV infection (AIDS), multiple sclerosis, degenerative neurological disorders N O N PAT H O L O G I C A L LY A N D PAT H O L O G I C A L SIGNIFICANT IN CSF Lining cells = choroidal cells or Any for of a blast (1st stage of a hemopoietic cell) – ependymal cells seen in acute leukemias Lymphoma cells also can be seen Malignant cells – astrocytoma, retinoblastoma, medulloblastomas – usually dark, ugly and in clusters. Cells fuse together. 7  6/26/2024 CHEMISTRY TEST What tube is used? Tube 1 (Most common test Protein & Glucose) Filtrate of the plasma - Low molecular weight Reference ranges ≠ plasma values Protein = 15 – 45 mg/dL Albumin (predominately), prealbumin, α globulins =haptoglobin & ceruloplasmin β globulins = transferrin, carbohydrate deficient transferrin (TAU) Gamma globulins = IgG, IgA, IgM CHEMISTRY TEST Significance Decreased protein indicates a leak in CNS Elevated protein: Damage to blood-brain barrier Testing methodology = total protein 1. Turbidity (automated instruments)- nephelometry Immunoglobulin production in the CNS CSF/serum albumin index IgG index (compares the albumin to IgG) Neural tissue degeneration 2. Dye binding ability Oligoclonal bands (immunoglobins in CSF) See Box 10-1 Electrophoresis Myelin Basic Protein (from the myelin of the sheath surrounding the nerves) ↑ in trauma, encephalitis, Guillain-Barre, lupus and brain tumors 8  6/26/2024 CHEMISTRY TEST Glucose Selectively transported NORMAL RANGE is 60% - 70% of the plasma glucose CSF glucose should be compared to a serum glucose within 2hours of the tap 2 additional chemistry test (send out) Elevated glucose is related to a high serum glucose Lactate Decreased glucose = significant helps with diagnosis and managing meningitis ↓ glucose + ↑ WBCs (neutrophils) = bacterial >25 mg/dl = meningitis meningitis Hypoxia ↓ glucose + ↑ WBCs (lymphocytes) = tubercular Used to monitor bad head injuries meningitis Glutamine Normal glucose + ↑ WBCs (lymphocytes) = viral Produced by ammonia and α-ketoglutarate meningitis Normal 8 – 18 mg/dl Elevated in liver disease Table 10-4 MICROBIOLOGY TEST Aide in analyzing the CSF for organisms Micro test can take 24 hours to 6 weeks depending on the organisms CSF culture confirm results Preliminary test Grams stain & Acid-fast stain India ink Latex testing (on the way out) Molecular testing (nucleic acid amplification) PCR 9  6/26/2024 MICROBIOLOGY TEST Latex agglutination test / lateral flow assay – replaced India ink C. Neoformans Antigen panel – Strep. B, H. flu, Strep. pneumo., N. meng A, B, C, Y & W135, E coli K1 Naegleria fowleri – parasite in water source enters through the nose and migrates to the brain Serology test for syphilis = VDRL (similar to RPR in serum) P O S TA M B L E READ the TEXTBOOK for the details to answer the UNIT OBJECTIVES. USE THE UNIT OBJECTIVES AS A STUDY GUIDE All test questions come from detailed material found in the TEXTBOOK (Not this PowerPoint) and relate back to the Unit Objectives 10