It is recommended to use atraumatic needle. The size of the needle must be large enough to extract fluid safely, efficiently and measure accurate opening pressures. Spinal needles smaller than 22G can provide misleading opening pressure readings and can take up to 6 minutes to drain 2mL of CSF. The 20-gauge needle can also serve as basic guidance for the spinal needle's general direction. In other words, if the 20-gauge needle meets bone in one direction but not in another, the appropriate direction to aim the spinal needle is confirmed. The smallest needle size suggested for diagnostic and therapeutic LPs is 22G. Using the index finger, stabilize the spinal needle and insert it into the skin using the thumb at a slightly cephalad angle directing it towards the umbilicus. The bevel of the needle is oriented parallel to the longitudinal dural fibers to separate the fibers instead of cutting. The bevel should be facing up in the lateral recumbent position and left or right in the sitting position.