Lumbar puncture - Results 

Some tests involving cerebrospinal fluid (CSF), such as a white blood cell count or checking for red blood cells, can be done quite quickly.

In the case of a medical emergency, the test results should be available within a couple of hours.

Other tests, such as checking for bacteria, are more complex and may take 48 hours to complete.

In non-emergency cases, such as having a lumbar puncture to help confirm or rule out a diagnosis of Guillain-Barré syndrome, it may take several weeks for the results to become available.