Introduction
Cisternal puncture (CP), also known as suboccipital puncture, is a medical technique initially used to obtain a sample of cerebrospinal fluid (CSF) from the subarachnoid space1. Cervical puncture (CerP), which is also a way to access the CSF in the lateral upper cervical spinal region, is an alternative to this technique, which has also been described similarly2. While not as commonly performed as lumbar puncture (LP), CP and CerP play a crucial role in diagnosing and managing various neurological conditions2.
CSF surrounds the brain and spinal cord, and its analysis provides valuable information about infections, hemorrhages, tumors, and other pathologies. Unlike LP, which is performed at the lower lumbar level, CP occurs just below the skull in the cisternal space3, while CerP performs a lateral puncture for accessing the upper spinal canal2.
Some of the current applications of these techniques include:
− Diagnostic sampling: They allow the collection of CSF for biochemical, microbiological, and cytological analysis4. This can aid in diagnosing infections, tumors, and other neurological conditions.
− Intrathecal medication: These procedures enable the direct introduction of medications into the meningeal space. For instance, they can be used to administer contrast agents for myelography or to deliver therapeutic drugs5.
− Increased intracranial pressure: In cases of elevated intracranial pressure or hydrocephalus, they may be used as a therapeutic measure to drain excess CSF and relieve symptoms6.
Despite their historical significance, CP and CerP are now less commonly performed due to advances in other diagnostic techniques. However, they remain relevant in specific clinical scenarios: their diagnostic accuracy and ability to detect early neurological diseases make them a valuable tool in medical practice.
In this article, we will explore the indications, techniques, and clinical considerations associated with CP and CerP.
Clinical case
A 61-year-old female patient with a medical record of neurocysticercosis was scheduled for CSF sampling by LP. During the procedure, LP was performed, but CSF could not be obtained. Later, consultation was carried out with the Interventional Neuroradiology to perform sampling through CerP.
The patient was scheduled for CerP, achieving adequate sample collection without major peri- and post-procedure complications. The patient was discharged from a short stay on the same day.
Once the CerP was performed, the samples were sent for their analysis. The patient did not report any symptoms or adverse events related to the CerP.
Procedure description
Under conscious sedation, the patient was placed in a prone position, and an aseptic maneuver was carried out in the posterior cervical area. With fluoroscopy, the C1 and C2 cervical segments of the spine, the space between them, and the spinolaminar line were located.
Once the anatomical structures were identified, a simulation of the needle orientation through the overlay was performed using lateral and anteroposterior radiographic projections. The puncture site was anesthetized with lidocaine.
A 22 g needle was inserted medially using fluoroscopy guidance and continued to be advanced horizontally through planes of skin, connective tissue, trapezius, and occipital muscles; finally, resistance was encountered when reaching the dura mater. After penetrating the dura, it was advanced by 2 more millimeters, and the flow of CSF was verified. When no sample was obtained, the needle was repositioned caudally, making an angulation of approximately 30° (Fig. 1). It was verified again, and on verifying the successful exit of CSF, obtaining samples began (Fig. 2). A total of 25 mL of CSF was drained. Samples were sent for cytological and cytochemical studies and cultures, as well as a vial for storage in case, new tests were requested.

Figure 1 X-ray of the cervical spine showing the spinolaminar line in yellow and the posterior vertebral line in blue. Cervical puncture was performed near to the spinolaminar line, the needle is shown between them.

Figure 2 After the subarachnoid space was accessed, cerebrospinal fluid was collected and sent to analysis.
At the end of sampling, the needle was removed, and momentary compression was performed. The patient remained under surveillance for a few hours and did not report symptoms.
Early indications and techniques
The CP was first performed on living human patients by Dr. Alexandru Obregia in 19081 using a suboccipital approach where a needle was advanced along the inferior midline to the occipital protuberance7.
In 1919, Dr. Ayer described his technique of cisterna magna puncture, introducing a needle a thumbs length cranial to the spinal process of C1 in the cervical spine, directing the needle in the same orientation8. By 1920, the same author had published his experience with 43 patients, all of whom were successful9.
Initially, suboccipital punctures were performed for the sole purpose of obtaining CSF samples; however, with the advent of myelography, complication rates increased for this procedure, which led to the development of safer and more cost-effective techniques10.
By the 1960s, various specialists in neurosurgery and radiology began to perform procedures using the C1-C2 space as access11. The CerP previously described is an example of this technique2. The advantage of this modified technique was the possibility of performing myelography with fewer complications and more direct access to the subarachnoid space7,11.
Current use
With the advent of new non-invasive imaging techniques of the skull, brain, and central nervous system, mainly computed tomography and magnetic resonance imaging, the number of suboccipital puncture procedures decreased considerably, being relegated to patients with specific indications7. Likewise, lumbar access for contrast injection in myelograms gradually supplanted suboccipital or cervical access for myelograms, eventually falling into disuse.
Some of the current indications for CP or CerP include7,8,12:
− Failed or difficult LP
− Patients are not suitable for a radiographic investigation of the lumbar region
− Arachnoiditis, or infection of the site of the puncture
− Ankylosis or lumbar stenosis
− Spinal cord obstruction
− Intrathecal administration of drugs in patients who are not candidates for LP or radiographic investigation
− Stem cell transplantation
− Certain congenital spinal malformations.
Furthermore, some of the contraindications for these procedures include7,8:
− Lack of cooperation from the patient
− Local infection of the site of the puncture
− Coagulation disorders.
Regarding vertebral levels, CerP from C1-C2 is preferred over suboccipital access through the midline because a thickening forms in the subarachnoid space at the level of C2, allowing safer access for procedures to be performed6. In a lateral CerP, the remoteness of the vertebral artery from the puncture site provides a considerable safety margin for interventional manipulation with a lower risk of bleeding13. This may vary depending on the disease and anatomical configuration of the vertebral artery and posterior cerebral circulation of each patient.
As mentioned, the lateral CerP at C1-C2 has several indications for this procedure. The vast majority of cases in which this intervention is performed are those with neurological pathology who have been candidates for LP but in which samples or successful access could not be obtained in the procedure. Some of the common causes of failed LP, include6,12:
As previously discussed, these situations may encourage the physician to perform CerP or CP instead of LP.
For a lateral CerP, patients can be placed in a prone, lateral, or supine position with the head rotated, always keeping the possible access site visible6,14. The patient must be immobilized to prevent movement during the procedure. The puncture should be performed with a 20- to 23 g epidural needle and its stylet placed perpendicular to the patient (as close as possible to 90°) without changing its angulation until reaching the subarachnoid space6.
Unlike a LP, the needle does not have the same support due to loose connective tissue, so the interventional doctor or an assistant must maintain the position and angle of the needle at all times while the procedure is completed6,14.
For each vial or bottle of CSF, 1-2 mL must be collected, and samples can be obtained for storage in pathology, microbiology, and biochemistry laboratories4. If necessary, a larger sample can be collected as long as the patient is stable and viable for an extension in the duration of the procedure4,6.
As happened in the clinical case, if CSF does not come out when the needle is in the correct position, the needle can be redirected 30° caudally to have better access to the subarachnoid space. If bleeding occurs during the procedure, it should be suspended and the needle removed as soon as possible to avoid injury to the subarachnoid space that could lead to neurological disability.
Limitations and complications
The complication rate from a CerP is around 0.05%, according to studies15. The most common side effect recorded was headache, mostly mild to moderate in intensity and self-limiting. The second is nausea and vomiting.
One of the most feared complications of CerP is bleeding due to a puncture or dissection of the arteries of the posterior circulation. The anatomical variants and pain of the vertebral artery, especially in its V3 segment, increase the possibility of complications due to bleeding7. However, if there is suspicion of normal variations, the patient can be turned slightly to anteriorize the vertebral arteries and reduce the risk of injury.
This technique, despite its adverse effects and the emergence of safer procedures, continues to be used in selected patients with contraindications to LP15. Eighty-five percentages of neuroradiology departments in the United States perform this procedure at least once a year, and most interventional radiology and interventional neuroradiology programs consider CerP within their curricula16.
Certain authors have questioned the usefulness of CerP today, given access to imaging studies and diagnoses with a lower probability of complications. However, consensus among interventional radiologists and neuroradiologists has confirmed the usefulness of this study, as well as its value in the diagnosis and treatment of difficult patients15,16. Some studies have even hypothesized that CerP is an underused technique that could have a higher frequency in complicated cases2.
Another point to highlight is the low complication rate of this procedure when performed by trained physicians with a high number of cases of CerP2. This supports the proposal to reintroduce or reinforce the teaching of the puncture technique, as well as the dissemination of its diagnostic advantages.
Ongoing research
Despite their infrequent usage, CP and CerP continue to be the subject of scientific studies and reviews. In 2017, the use of a lateral atlanto-occipital puncture was proposed instead of the standard C1-C2 technique for CSF sampling. The results of their study demonstrated similar efficacy to traditional punctures with a lower complication rate. Among the most common adverse events were headaches and transient elevations of blood pressure17. This technique has also been tested experimentally in animals using ultrasound as imaging support for the procedure instead of radiographic projections3.
Likewise, CerP has regained utility for access to the epidural space18 and drug administration5 in patients with pathologies that limit the therapeutic approach through LP.
Conclusion
CP and CerP are safe and effective alternatives to performing procedures that involve access to the subarachnoid space whenever the LP is unsuccessful or is not significant.
Although rarely performed, they offer an alternative to LP. Despite their infrequent use, CP and CerP remain valuable techniques in specific clinical scenarios.









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