AUB - Cerebrospinal Fluid

CEREBROSPINAL FLUID     

3rd major fluid of the body Clear, colorless fluid Dialysate from the blood Does not resemble a plasma ultrafiltrate Major constituents are: Protein Glucose Chloride

LOCATION OF THE FLUID 



INTERNALLY ventricular fluid cisternal fluid spinal cord canal fluid EXTERNALLY between the pia and arachnoid membranes

PHYSIOLOGY AND SOURCES OF CSF:     

Formed in the highly vascular choroids plexuses Ventricles of the brain Secreted by the ependymal cells lining the ventricle Enters the subarachroid space through the Foramen of Lushcka and Magendie Enters venous blood through arachnoid villi of the dural sinuses

CEREBROSPINAL FLUID     

NORMAL RATE OF CSF FORMATION 500cc/day or 20 cc/hr NORMAL CSF volume of a healthy person 150 cc/day Spinal canal 70cc Subarachnoid space 60cc Ventricles 20cc

FUNCTIONS OF THE FLUID    

Protection of the brain from injury by acting as a fluid buffer Acts as a medium of exchange for the transfer of dialyzable material between the blood stream and the spinal cord Equalizes the pressure between the brain and the spinal cord Serves as an excretory channel in the elimination of products of nervous metabolism

BARRIER CONCEPTS IN CSF    

Regulate inflow & outflow of fluid and ions Blood-CSF Barrier: between subarachnoid space & pia mater CSF-Brain Barrier: subarachnoid space, pia mater & brain surface Blood-Brain Barrier: between pia mater & brain

BLOOD-CSF BARRIER opened reversibly by:    

Acute hypertension Seizures Hypercapnea Radiograph dyes

COLLECTION OF THE FLUID

TYPES   

OF PUNCTURE: LUMBAR PUNCTURE CISTERNAL PUNCTURE VENTRICULAR PUNCTURE

INDICATIONS FOR LUMBAR PUNCTURE Suspected inflammation  Meningitis  Encephalitis (neurosyphilis)  Brain abscess  Subarachnoid hemorrhage  Leukemia in CNS  Multiple sclerosis  Spinal cord tumor Differential diagnosis  Cerebral infarct VS. Intracerebral hemorrhage Introduction of radiographic dyes & drugs  Anesthetics  Contrast media  Methotrexate (Meningeal leukemia)  Amphotericin (Fungal meningitis) Treatment  For patients with benign intracranial hypertension EMERGENCY LUMBAR PUNCTURE  Suspected meningitis  Subarachnoid hemorrhage  Leukemia in CNS COMPLICATIONS OF LUMBAR PUNCTURE: Herniation  Uncus through cerebellar tonsils, Foramen of Magnum Progressive paresis & paralysis  Increase intracranial pressure  With spinal cord tumor Paraplegia  Result of extradermal or subdural hematoma on patients with clotting defects (thrombocytopenia) Meningitis  Presence of sepsis  Perforation of meninges Asphyxia (infants)  Excessive restraint  Tracheal obstruction Epidermoid tumors  No stylet is used  Period of development is 2-10 years Introduction to infection  Passing of needle superficially in lumbar region  Deep sepsis Post lumbar puncture headache / Spinal headache  Resulting from leakage of CSF COMPOSITION OF NORMAL SPINAL FLUID Glucose Sodium Phosphorus, inorganic Chlorides HCO3

Urea Potassium Uric Acid PCO2 Total protein

Fibrinogen – none Albumin Alpha 2 – globulin Gamma globulin Magnesium Glutamic oxalacetic transaminase Phosphohexose isomerase

Prealbumin Alpha – globulin Beta and tetraglubin Calcium (lumbar) Creatinine Lactic dehydrogenase

MACROSCOPIC OR PHYSICAL EXAMINATIONS       

Amount Pressure Color Transparency Coagulation Reaction Specific gravity

GRADING OF TURBIDITY 0 - Crystal clear 1- Faintly cloudy, smoky, hazy, slight (barely visible) turbidity 2 - Turbid but newsprint readable 3 - Newsprint not readable 4 - Newsprint cannot be seen CAUSE OF TURBIDITY    

Leukocytes Erythrocytes Microorganisms Increase protein or glucose

CLINICAL SIGNIFICANCE OF CSF APPEARANCE

CHEMICAL EXAMINATION    

PROTEINS GLOBULIN QUALITATIVE TESTS GLUCOSE CHLORIDE ALBUMIN – GLOBULIN RATIO TEST – LANGE’S COLLOIDAL GOLD TEST

Other Tests for CSF:       

Borowskaja’s Modification of Lange’s Test Mastic Test Alkaline – Saline Solution Colloidal Benzoin Test Turbidity Test Tryptophan Test Automated Tests

XANTHOCHROMIA   

ABNORMAL CSF COLOR Normal in premature infants Pigments contributing to xanthochromia: Pink: Methemoglobin / Oxyhemoglobin Yellow: Bilirubin Increase CSF Protein: Froin syndrome-yellow color H CHON Antiseptic contamination: Iodine Carotenoids: Systemic hypercarotemia Melanin: Meningeal melanosarcoma

SAMPLE COLLECTION OF CSF BOTTLE #1 - CHEMISTRY & SEROLOGY  

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left to right: normal, xanthochromic, hemolyzed, cloudy Traumatic tap VS. Subarachnoid hemorrhage -

With clotting 1st bottle: bloody 2nd bottle: clear 3rd bottle: clear With xanthochromia

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No clotting 1st bottle: bloody 2nd bottle: bloody 3rd bottle: bloody With xanthochromia

Glucose Total proteins Qualitative tests  Lange Colloidal Gold test  Pandy’s test Electrophoresis Myelin Basal reaction or C-Reactive Protein Normal values: Albumin: 10-30 mg/dl Calcium: 2.7-3.1 meq/L Cell count: 0-5 cells/uL Chloride: 110-132 meq/L Glucose: 50-80 mg/dL Protein  Total CSF Protein: 15-45 mg/dL  Ventricular CSF Protein 5-15 mg/dL  Xanthochromia: Negative

Immunologic studies: 

CSF FTS-ABS Treponemal (Fluorescent Treponemal Antibody Absorption Test): for neurosyphilis

   

VDRL Non-Treponemal (Venereal Disease Research Laboratory) ELISA (Enzyme-Linked Immunosorbent Assay) Latex Agglutination: Cryptococcal antigen Millipore / Nucleopore filter techniques

BOTTLE # 2 - MICROBIOLOGY    

Gram stain: bacterial contamination or meningitis India ink preparation: fungal meningitis Acid fast stain: Tubercular meningitis Culture

BOTTLE # 3- CELL & DIFFERENTIAL COUNT CSF WBC Count   

WBC added = WBC blood X RBC CSF RBC blood CSF Proteins Differential Count Centrifugation with Wright’s stain & re-suspend sediment Sedimentation methods Cytocentrifuge & related methods

CSF CONSTITUENTS IN DISEASES:

Broad spectrum of lymphocytes and monocytes in viral meningitis

INDIA INK & GRAM STAIN (Starburst pattern) C. neoformans