Lesson 2: What is the cerebrospinal fluid test for?

Posted by Master, Doctor Tran Thi Vuong - Doctor of Microbiology - Laboratory Department - Vinmec Hai Phong International General Hospital

When the central nervous system is damaged, the cerebrospinal fluid will have corresponding changes. The examination of cerebrospinal fluid will guide as well as help clinicians make a definite diagnosis and provide appropriate treatment.

Normally, the adult body usually has 150-180 ml of cerebrospinal fluid (DNT), which is a clear, colorless substance contained in the ventricles, subarachnoid space and cisterns...
CSF has the following functions: Protects the central nervous system against mechanical trauma, ensures the circulation of nervous fluids, hormones, antibodies and white blood cells, participates in the regulation of pH and balance Electrolytes of the central nervous system...

When the central nervous system is damaged, the cerebrospinal fluid will have corresponding changes. The examination of the cerebrospinal fluid will guide as well as help the clinician to make a definite diagnosis.
Time of collection: By clinician's examination and decision making
Method of collection: This technique is performed by a specialist by lumbar puncture.
Container: Use an antifreeze-free tube, usually a sterile plastic tube or vial with a tight screw cap.
Collected volume: Usually 2 - 3ml is taken and divided into 3 tubes
Tube 1: Do biochemical and serological tests: To perform quantification of sugar, protein, chloride, antibodies... Tube 2 : Do microbiological tests: Staining, culturing, identifying and making antibiotics, PCR looking for viruses, bacteria... Tube 3: Cytological testing: Find the number and composition of white blood cells. Normal cerebrospinal fluid is colorless, transparent, normal cerebrospinal fluid density is 1,006-1.009, pH is 7.4-7.6, cell count: 0-3 cells/ml of fluid, sugar indicators (glucose) , protein (protein), chloride salt, within the allowable threshold, no microorganisms exist (sterile).

When tested, these changes are indicative or sign of infectious diseases, trauma or tumors, thrombosis, cerebral artery occlusion...
For example in purulent meningitis : CSF is cloudy, the number of cells is increased (500-1000 cells/ml), mainly neutrophils, protein is increased, glucose is decreased, staining and culture isolated pathogenic bacteria (pneumococcus). , meningococcal...). In tuberculous meningitis: CSF is lemon yellow, clear, cells are increased, mainly lymphocytes, protein is usually slightly increased, glucose and salt are decreased, Zielh-Neelssen staining residue can be seen by centrifugation. TB bacteria, CSF PCR results positive for TB bacteria...In viral meningitis: CSF is usually still transparent, Protein is slightly increased, performing PCR tests will find the cause of the disease.. .In addition, in the pathology of tumors, hemorrhage, CSF changes again.
Therefore, the test of cerebrospinal fluid along with imaging will help the clinician to accurately diagnose the patient's medical condition and provide an appropriate treatment regimen.

Vinmec International General Hospital with a system of modern facilities, medical equipment and a team of experts and doctors with many years of experience in medical examination and treatment, patients can rest assured to visit. examination and treatment at the Hospital.