Suboccipital puncture
A suboccipital puncture or cisternal puncture is a diagnostic procedure that can be performed in order to collect a sample of cerebrospinal fluid (CSF) for biochemical, microbiological, and cytological analysis, or rarely to relieve increased intracranial pressure. It is done by inserting a needle through the skin below the external occipital protuberance into the cisterna magna and is an alternative to lumbar puncture. Indications for its use are limited. Subarachnoid hemorrhage and direct puncture of brain tissue are the most common major complications. Fluoroscopic guidance decreases the risk for complications. The use of this procedure in humans was first described by Ayer in 1920.