The normal pressure of cerebrospinal fluid (CSF) typically ranges from 70 to 180 mm H2O.
This measurement is usually taken during a lumbar puncture (spinal tap), a procedure where a needle is inserted into the lower back to collect a sample of CSF. The pressure is an important indicator of various conditions affecting the brain and spinal cord.
Factors Affecting CSF Pressure
Several factors can influence CSF pressure, including:
- Body position: The pressure is usually higher when lying down compared to sitting.
- Respiratory cycle: Fluctuations can occur with breathing.
- Underlying medical conditions: Infections, tumors, and other conditions can affect CSF pressure.
Significance of Abnormal CSF Pressure
Deviations from the normal CSF pressure range can indicate various medical problems:
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High CSF pressure (above 180 mm H2O): May suggest conditions like:
- Meningitis
- Encephalitis
- Subarachnoid hemorrhage
- Idiopathic intracranial hypertension (pseudotumor cerebri)
- Brain tumor
-
Low CSF pressure (below 70 mm H2O): May suggest:
- CSF leak (due to a tear in the dura mater, the membrane surrounding the brain and spinal cord)
- Dehydration
Other CSF Characteristics
Besides pressure, other CSF characteristics evaluated during a lumbar puncture include:
- Appearance: Normal CSF is clear and colorless.
- Protein levels: Normal CSF contains a certain amount of protein, typically between 15 to 60 mg/100 mL (0.15 to 0.6 g/L).
- Glucose levels: CSF glucose should be about 2/3 of serum glucose level.
- Cell count: Elevated white blood cells may indicate infection or inflammation.
In summary, the normal CSF pressure is 70 to 180 mm H2O, but clinical interpretation should always be made in conjunction with other CSF characteristics and patient symptoms.
