Lumbar Puncture

Also known as "spinal tap" or "LP". This procedure is done when it is necessary to collect cerebrospinal fluid from the patient.

Indications
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Procedure
The patient is usually placed in a left (or right) lateral position with his/her neck bent in full flexion and knees bent in full flexion up to his/her chest, approximating a fetal position as much as possible. A spinal needle is inserted above or below the L4 vertebra. At that level spinal cord is found in a form of floating filaments – cauda equina, thus avoiding any actual puncture on the spinal cord. The needle will pass the ligamentum flavum, and penetrate the dural sac in order to reach and puncture the arachnoid, to enter the subarachnoid space, where the CSF is located.