Cerebrospinal Fluid Analysis – Part 1 – Cerebrospinal Fluid Normal Findings(CSF)

Definition of the cerebrospinal fluid (CSF)

1. This is a clear, colorless, fluid similar to blood plasma and interstitial fluid.
2. Approximately 600 mL of the CSF is produced daily.
3. Around 125 to 150 mL of CSF circulates in the ventricles and subarachnoid space.
4. Choroid plexus in the lateral, third, and fourth ventricles produce a major portion of the CSF.
5. CSF does not accumulate but it is reabsorbed into venous circulation through arachnoid villi.
6. CSF is formed by the blood and after circulating throughout the CNS, it returns to the blood.

Function of CSF

1. The intracranial and the spinal cord float in the CSF and are therefore protected from the blows and the jolts.
2. The buoyant properties of the CSF prevent the brain from tugging on meninges. nerve roots, and blood vessels.
3. Its main function is to protect the brain and spinal cord from the injury.
4. It transports the substances through the central nervous system.

1. Appearance

   1. it is clear and colorless.
      1. This clear protein circulates in the subarachnoid space.
      2. No clot is seen.

2. Pressure

   1. It is 70 to 180 mm of H2O or 5 to 14 mm of Hg.
   2. This pressure is when the person is lying down and it doubles up when the person sits up.

3. Total cell count

   1. In adult is 0 to 5 / cmm .
      1. These are mononuclear cells.
   2. In infants are 0 to 20 / cmm.
   3. No RBC is seen.

4. Glucose

   1. It is 45 to 80 mg /dL .
      1. This is 20 mg /dL lower than the blood glucose level.
   2. Ventricular glucose is 5 to 10 mg higher than the lumbar CSF.

5. Protein

   1. It is 15 to 45 mg / dL in lumbar CSF.
   2. It is 15 to 25 mg / dL in the cisternal fluid.
   3. It is 5 to 15 mg / dL in the ventricular fluid.

6. Gamma globulin

   1. It is 3 to 12 % of the total protein.

7. Chloride

   1. It is from 120 to 130 meq / L.
   2. It is 20 meq higher than the serum.

8. LDH

   1. It is 15 to 17 units/L

9. Bilirubin

   1. It is negative.

Table showing Normal CSF findings:

Lab findings	Source 2	Source 1	Source 4
Volume		Adult 90 to 150 mL Child = 60 to 100 mL
Pressure	<20 cm H2O	50 to 180  mm H2O (If the pressure >180 mm H2O, then do not take more than 1 to 2 ml of CSF)	Adult = 90 to 180 mm H2O Child (<8 years) = 10 to 100 mm H2O
Appearance	Clear and colorless, no clot	Crystal clear, and colorless	Clear and colorless
Blood	Nil	Negative	Nil
White cell count	Neonates = 0 to 30 cell/µL	0 to 30 cells	Adult = 0 to 5 WBC/µL Newborn = 0 to 30 WBC/µL Child = 0 to 15 WBC/µL
	1 to 5 years = 0 to 20 cells/ µL
	6 to 18 years = 0 to 10 cells/  µL Adult = 0 to 5 cells/ µL	0 to 5 cells
Differential count
Neutrophils	0 to 6%	Adult = 0 to 6% Newborn = 0 to 8%	Adult = 0 to 6% Newborn = 0 to 8%
Lymphocytes	40 to 80%	Adult = 40 to 80% Newborn = 5 to 35%	Adult = 40 to 80% Newborn = 5 to 35%
Monocytes	15 to 45%	Adult = 15 to 45% Newborn = 50 to 90%	Adult = 15 to 45% Newborn = 50 to 90%
Protein	15 to 45 mg/dL It is high in elders and children upto 70 mg/dL		Adult = 15 to 45 mg/dL = lumbar 15 to 25 mg/dL = Cisternal 5 to 15 mg/dL = Ventricular Neonates = 15 to 100 mg/dL Adults >60 years = 15 to 60 mg/dL
Lumbar  area		Adult = 15 to 45 mg/dL Neonates = 15 to 100 mg/dL >60 years = 15 to 60 mg/dL	Adult = 15 to 45 mg/dL
Cisternal area		15 to 25 mg/dL	Adult = 15 to 45 mg/dL = lumbar
Ventricular area		5 to 15 mg/dL	Adult = 5 to 15 mg/dL
Electrophoresis
Prealbumin	2 to 7%		2 to 7%
Albumin	56 to 76%	10 to 35 mg/dL	56 to 76%
Alpha1 globulin	2 to 7%		2 to 7%
Alpha2 globulin	4 to 12%		4 to 12%
Beta globulin	8 to 18%		8 to 18%
Gamma globulin	3 to 12%		3 to 12%
IgG	0 to 4.5 mg/dL		<4.0 mg/dL
Oligoclonal band	Negative		Negative
Biochemical estimation
Glucose	50 to 75 mg/dL (60 to 70% of blood glucose)	Infant, child = 60 to 80  mg/dL Adult = 40 to 70 mg?dL	Adult = 40 to 70 mg/dL Child = 60 to 80 mg/dL CSF/plasma glucose ratio = <0.5 CSF glucose level 60 to 70% of the blood
pH		Lumbar area= 7.28 to 7.32 Cisternal area = 7.32 to 7.34
Sodium		135 to 160 meq/L
Potassium		2.6 to 3.0 meq/L
Chloride	700 to 750 mg/dL	115 to 130 meq/L	Infant = 110 to 130 meq/L Adult = 118 to 132 meq/L
LDH	<2 to 7.2 units/mL	<20 U/L	Adult = <20 U/L (around 10% of serum)
Lactic acid	10 to 25 mg/dL	10 to 24 mg/dL	Adult = 10 to 22 mg/dL Newborn = 10 to 60 mg/dL
Glutamine	6 to 15 mg/dL	Neonates = 10.34 ± 3.6 mg/dL 3 months to 2 year = 7.27 ± 1.3 mg/dL 2 to 10 years = 6.76 ± 1.20 mg/dL Adult = 8.61 ± 0.50 mg/dL
Urea nitrogen		6 to 16 mg/dL
Phosphorus		1.2 to 2.0 mg/dL
Creatinine		0.5 to 1.2 mg/dL
Uric acid		0.5 to 4.5 mg/dL
Bilirubin		Negative
ammonia		10 to 35 µg/dL
Syphilis serology	Negative	Negative	Negative
CSF cytology for malignancy	Negative	Negative	Negative

 

---