Cerebrospinal fluid - role

Transcription

1 Cerebrospinal fluid

2 Cerebrospinal fluid CSF is a mixture of fluid generated locally in the brain and filtered serum Total volume 150 ml (the fluid that fills the cerebral ventricles, subarachnoid space along the spinal canal ) Physiological daily production 500 ml, exchanged 3 times per day

3 Cerebrospinal fluid - role mechanical protection of brain and spinal cord maintenance of fluid and electrolyte homeostasis of the nervous system receptor contact between CNS and blood

4 CSF indications for specimen collection CNS hemorrhage Meningitis Abscess Subarachnoid hemorrhage Brain tumors Demyelinating diseases cutaneous lesions

5 CSF specimen collection Lumbar puncture (L4-5 or higher) 2-3 ml from midstream, even up to 20 ml when the pressure is mmhg When the pressure is higher or lower 1-2 ml

6 Cerebrospinal fluid Examination steps: Macroscopic examination (color, clarity) Biochemical and immunological analysis (protein, glucose and chloride level) Microscope analysis of sediment (cytosis, cytogram and morphology) CSF is collected to three subsequent probes:

7 Normal CSF - macroscopic characterisation Colorless Crystal clear Doesn t clot Lack of sediment after centrifugation

8 CSF color Normal is crystal clear, colorless Red color of CSF Centrifugation Red color disapears; red sedimentaion appears Red color remains Puncture mistake Capillars broken during syringe prick Xanthochromia? Subarachnoid haemorrhage, hyperbilirubinemia Red, pink, yellow or orange discoloration

9 Protein level CSF has characteristic protein composition mg/dl Elevated level: infections, intracranial hemorrhages, malignancies, inflammatory conditions Do not fall in hypoproteinemia Main aim of total protein and specific proteins examination in CSF is the evaluation of blood- CSF barrier (its permeability) and the detection of intrathecal immunoglobulin synthesis Fraction Serum (%) CSF (%) Pre-albumins - 1,2 albumins 56 56,1 α1-globulines 5,7 4,7 α 2-globulins 9,4 7,5 β-globulins 12,4 14,1 Tau protein - 10 γ-globulins 16,5 6,4

10 Protein level - tests They allow you to quickly specify changes in the concentration of albumin and globulins Pandy's test Globulin + albumin Precipitation of a saturated solution in phenol proteins => turbid appearance impaired permeability of the blood-brain barrier Nonne-Appelt s test Globulin precipitation in ammonium sulfate disturbed ratio of albumin/globulins inflammatory diseases associated with synthesis of fibrinogen

11 Glucose level Depends on serum concentration mg/dl (2/3 of serum concentration) Hyperglycemia Diabetes Stroke CNS infection Chemical meningitis Subarachnoid hemorrhage hypoglycemia

12 Chloride Concentration higher than in serum mmol/l Meningitis Brain tumors Spinal cord inflammation Tuberculosis Syphilis Huntington disease

13 Cytosis Cytosis Adults Newborn children and infants 0-5 cells/µm cells/µm 3 70% lymphocytes, 30% monocytes 70% monocytes, 30% lymphocytes turbid fluid protein level Erythrocytes - zero Has to be counted in two hours autolysis cytosis (higher than 300/uL)

14 Differentiation of various types of meningitis Bacterial Viral Fungal Tubercular WBC count >1000/mm 3 <100/mm 3 Variable Variable Cell differential neutrophiles lymphocytes lymphocytes lymphocytes Protein N CSF-to-serum glucose ratio N Cl - N N N

15 Other body fluids

16 Body fluids - potential spaces Pleural cavity Peritoneal cavity The linning of the pericardial sac and the surface of the heart Synovial cavity

17 Body fluids- serous fluids Are classified as either transudates and exudates Transudates are generated due to plasma oncotic and hydrostatic pressure Exudates are generated due to disrupted capillary permeability They differ from each other in specific gravity, protein level, LDH level and cytosis

18 Transudates Caused by the penetration of liquid, low protein and serum components of blood outside the vascular bed Under the effect of reduced oncotic pressure or increased hydrostatic pressure, intravascullar extracellular fluid leaks out of the vascular bed by the intact vascular wall Characterisation: low protein content (<3,0 g/dl) low specific gravity (< 1.016) low nucleated cell counts (less than 500 to 1000 /ul) primary cell types are mononuclear cells: macrophages, lymphocytes and mesothelial cells Clear, yellowish (like serum)

19 Exudates Inflammatory fluids accumulating in serous cavities of the body with ensuing damage of the blood vessel wall Usually effusions result from an inflammatory response to conditions that directly affect the serous cavity like infections and malignancies Characterisation: high protein content (>3,0 g/dl) high specific gravity (> 1.016) high nucleated cell counts (>1000 /ul) turbid with solidifying strands of fibrin or precipitated fibrinogen xanthochromia, milky

20 Body fluids specimen collection

21 Body fluids macroscopic characterisation Light yellow - transudate Gold collor cholesterol? Amber billious?

22 Body fluids biochemical characterisation Biochemical analysis: Lactate dehydrogenase Protein Glucose Amylase pancreatic juice Light factor = fluid serum LDH Q > 0,6 Protein Q > 0,5 Exudate!!

23 Body fluids - differentiation < 500 cells/ul SG < 1,016 ph > 7,29 > 1000 cells/ul SG > 1,016 ph < 7,29 transudate exudate

24 Differentation of transudates and exudates Transudate Exudate Specific gravity < 1,016 g/ml > 1,016 g/ml Protein < 3 g/dl > 3 g/dl Protein Light factor <0,5 > 0,5 LDH <200 >200 LDH Light factor <0,6 >0,6 Cells single >1000 cells/µl