A lumbar puncture is a puncture of the dural sac in the lumbar spine for the purpose of diagnostic or therapeutic collection of Cerebrospinal fluid.
Procedure
A hollow needle is inserted into the lumbar canal below the first and second lumbar vertebral bodies, and cerebrospinal fluid is collected. A lumbar puncture is usually performed at the level between the fourth and fifth lumbar vertebral bodies. Lumbar puncture is the most common method of cerebrospinal fluid collection. In neurosurgery, lumbar puncture is frequently performed in cases of imaging-negative Subarachnoid hemorrhages as well as for the CSF tap test in patients with Normal-pressure hydrocephalus.
Opening pressure
Opening pressure is the pressure measured immediately after performing a lumbar puncture. The measurement can be performed using a so-called standpipe. A study of 242 adults showed a 95% reference interval of 10 to 25 cmCSF as the normal opening pressure, with minor variations depending on the patients’ BMI[^1]. To reliably measure opening pressure during lumbar puncture, the procedure should be performed with the patient lying down rather than sitting.
Contraindications
Both superficial and deep inflammation of the skin or subcutaneous tissue, as well as inflammation of the muscles in the area of the puncture site, constitute a contraindication to lumbar puncture.
Disorders of cerebrospinal fluid circulation, such as the presence of Aqueductal stenosis.
Increased Intracranial pressure with a risk of Herniation.
Risks
Lumbar puncture is a commonly performed procedure, and serious complications are rare. The most common complication after lumbar puncture is post-dural puncture headache, occurring in approximately 32% of cases[^2].
