Normal Values:

The normal white blood cells are between 0 and 5. The normal red blood cell count is 0.

What abnormal results mean:

An increase of white blood cells indicates infection, inflammation or bleeding into the cerebrospinal fluid. Some causes include:

• Abscess
• Acute infection
• Encephalitis
• Hemorrhage
• Meningitis
• Multiple sclerosis
• Stroke
• Tumor

The finding of red blood cells may be a sign of bleeding. However, red blood cells in the CSF may also be due to a traumatic spinal tap, which can happen if the spinal tap needle hits a blood vessel while entering the skin or dura.

It is important to see if the red blood cell count clears in samples taken later in the procedure as opposed to earlier. A ratio of the red blood cells to the white blood cells is also calculated to help with diagnosis.

Additional conditions which this test may help diagnose include:

• Arteriovenous malformation (cerebral)
• Cerebral aneurysm
• Delirium
• Dementia
• Epilepsy
• Guillain-Barre syndrome
• Hemorrhagic stroke
• Neurosyphilis
• Primary lymphoma of the brain
• Spinal tumor
• Stroke secondary to syphilis
• Syphilitic aseptic meningitis
• Syphilitic myelopathy