CSF examination :
يارب اجعل العمل خالصا لوجهك، نوجه إلى أنه يوجد بوست آخر جامع أكثر من هذا للأطباء العاملين بمجال التحاليل
What's CSF :
Cerebrospinal fluid (CSF) is a clear, watery fluid that surrounds the brain and the spinal cord.
CSF production, circulation, and clearance :
The CSF is produced by the choroid plexus
The fluid will move from the lateral ventricle to ➡ the third and then to the ➡ fourth ventricle, then the fluid moves out into ➡ the subarachnoid space and/or the central canal of the spinal cord.
Finally, ➡ CSF gets drained into the superior sagittal venous sinus through the arachnoid villi.
Around 500 ml is produced each day, with around 150 _ 250 ml being present in the body at any one time.
Function of CSF :
1_ Buoyancy
2_ protectin
3_ Homeostasis
4_ clearing waste
5_ Nutrition.
_______________
When required :
امتى بيطلب التحليل
_ Altered sensorium
_ Coma
_ Unconscious patient
_ Suspected meningitis
_ trauma to the brain or spinal cord
_ Mood swings, depression, confusion, hallucinations, or seizures
_ Infants may be increasingly irritable, cry when they are held, have body stiffness, refuse food,...
فوائد التحليل
CSF testing may reveal more directly the cause of CNS conditions.
The following are some examples:
1_ Meningitis and encephalitis
2_ Autoimmune diseases such as Guillain-Barré syndrome or multiple sclerosis
3_ Cancers of the CNS or cancers that have spread to the CNS, such as leukemia
4_ Alzheimer's disease, an irreversible form of dementia.
5_ bleeding around the brain.
_______________
Test Preparation :
You will be instructed to empty your bladder and bowels before sample collection. It will be necessary to lie still in a curled-up fetal position during the collection and to lie flat and still for some time after the collection.
سيُطلب منك تفريغ المثانة والأمعاء قبل جمع العينة. وسيكون من الضروري الاستلقاء في وضع الجنين الملتوي أثناء التجميع والاستلقاء بشكل مسطح وثابت لفترة زمنية بعد التجميع.
May sitting position.
_______________
Collection of CSF :
في الغالب
Lumbar puncture needle is inserted between the 3rd and 4th lumbar vertebrae, within 2% procaine.
The pressure should be measured by manometer then 3-4 ml are allowed to drip into sterile plain tubes
_______________
Collection and stability :
نجمع 12 مل في 4 عينات
1_ Biochemistry➡ glucose, protein,...
2_ Hematology ( cell count)
3_ Microbiology➡ Gram stain, culture & sensitivity
4_ cytology, Serology or PCR,... etc
Sample stability :
RBCs and WBCs have limited stability so #timing is critical for WBCs to diagnose meningitis or leukemic involvement
_______________
Gross examination :
1_ Appearance and color :
Normal ➡ clear, watery, colorless liquid
Any color is abnormal
_ Reddish ➡
traumatic tap
الأنبوبة الأولي حمراء ويقل تدريجيا في الأنابيب التالية.
intracranial bleeding
كل الأنابيب حمراء
_ Yellow color (xanthochromia) ➡
Previous hemorrhage
نتيجة تكسير كرات الدم الحمراء وظهور البيلوربين
Grossly increased protein
_ Green CSF ➡ may also sometimes be seen with bilirubin or infection.
2_ Turbidity :
Normal is clear
Turbidity may be Infection of CSF / meningitis
3_ Fibrin clot :
Webbed fibrin clot in TB
traumatic fibrin clot
4_ Specific gravity :
Normal 1. 006 _1. 008
5_ pressure :
Normal ➡ 50_175 mm H2O
_ Increased CSF pressure ➡ obstruct the flow of CSF, such as tumors, infection, (hydrocephalus)
_ Decreased pressure ➡ dehydration, shock, leakage,...
Viscosity :
Normal CSF is watery
CSF that is thicker may be seen in people with certain types of cancers or meningitis.
_______________
Chemical examination :
1 _ CSF glucose :
Done as serum by glucose oxidase method
CSF glucose (fasting state) ➡ 40_80 mg/dl
Decreased in glucose indicate Meningitis
Very low glucose seen in bacterial meningitis
Slightly low glucose seen in viral and TB meningitis
Dr
17:04
2_ CSF protein :
Normal level 15_45 mg/dl
Can't be detected by biurets method, it can be detected by :
the dye-binding method as pyrogallol red / coomassie brilliant blue
Increased CSF protein occurs in :
Infection ( meningitis)
CSF obstruction by tumor trauma, inflammation
Guillain Barre syndrome, multiple sclerosis ➡ ⬆ IgG
About 95% of cases of multiple sclerosis patients have positive findings of increased CSF / serum Ig concentration ratio and #oligoclonal band on electrophoretic separation of CSF.
_______________
Hematology examination :
Do cell count of the CSF by cell counter (hemacytometer)
If cells are increased make a smear and see the nature of the cell present
علشان نعمل
Differential WBCs count
Normal CSF cytology :
1_ RBCs ➡ absent
2_ WBCs ➡ 0_5 /μL
Newborn up to 30/μL
Type of WBCs ➡ lymphocyte
60_80% ➡ lymphocyte
30%. ➡ Monocyte
2%. ➡ Others
RBCs
If present you should tell us if it's crenated or not as crenated RBCs may be seen in subarachnoid hemorrhage
Traumatic tap has normal RBCs
WBCs :
Increased cell: infection
Neutrophils ➡ bacterial meningitis
Lymphocyte ➡ viral, TB, fungal, syphilitic, or aseptic meningitis
_______________
