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
Lumbar puncture (LP), also known as a spinal tap, is a medical procedure in which a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing. The main reason for a lumbar puncture is to ...
. Indications for its use are limited.
Subarachnoid hemorrhage
Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consci ...
and direct puncture of brain tissue are the most common major complications.
Fluoroscopic
Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal anatomy, structure and ...
guidance decreases the risk for complications. The use of this procedure in humans was first described by Ayer in 1920.
This is an exceedingly rare procedure. When CSF cannot be obtained from the lumbar space (and when its analysis is considered critical to treatment), a cisternal tap may be required. The needle is placed in the midline, passing just under the occipital bone, into the (usually large) cisterna magna (Fig. 23-2). This is technically fairly easy; however, if the needle is advanced too far it can enter the medulla, sometimes causing sudden respiratory arrest and death. The test should therefore be carried out only by experienced physicians (usually neurosurgeons or neuroradiologists). An alternative route that may be used by neurosurgeons and neuroradiologists is lateral to C-1 with penetration through the large C-1 intervertebral hiatus.
The cisternal tap may be used in myelography when the upper margin of a spinal block needs to be defined; however, magnetic resonance imaging (MRI) has become the procedure of choice for defining the upper and lower limits of spinal cord or spinal cord-compressing lesions. It is necessary at times in the intrathecal administration of irritating medications, such as amphotericin B. Medications are diluted more rapidly in the larger and more rapidly circulating volume of cisterna magna than in the smaller lumbar sac.
See also
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Lumbar puncture
Lumbar puncture (LP), also known as a spinal tap, is a medical procedure in which a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing. The main reason for a lumbar puncture is to ...
References
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{{DEFAULTSORT:Suboccipital Puncture
Neurological disorders