Neuro(b)log for Patients

Practical information, preparation, procedure and specific advice from neurological practice

Introduction

As a neurologist with many years of hospital practice, I have gathered extensive experience with lumbar puncture over the course of my career. In the first years after graduation I worked on a neurology ward in a regional hospital in Vysočina, where there were practically only two physicians responsible for running the department. I therefore quickly gained a wide range of experience and encountered many diagnoses. On some days I performed cerebrospinal fluid collection on up to three patients; overall, in those early years after graduation I performed this invasive procedure on more than 2,500 patients (and I stopped counting thereafter), and I had the opportunity to observe their recovery. Based on this practice I offer you clear, practical information and advice that truly reflect everyday clinical practice. Many patients feel anxious at the mention of lumbar puncture, cerebrospinal fluid collection or a liquorological examination, and these fears often worsen when they search for information and read negative experiences — the aim of this article is to alleviate those fears and provide clear, verified information.

What is a lumbar puncture

The first lumbar puncture was performed in the 19th century by the German physician Heinrich Irenaeus Quincke (1891). The term refers to the collection of cerebrospinal fluid (CSF). It is an invasive procedure in which a physician inserts a thin needle into the area between the lumbar vertebrae (usually between the 3rd and 4th or 4th and 5th lumbar vertebrae, sometimes lower, i.e., between the 5th lumbar and 1st sacral vertebra) into the subarachnoid space and withdraws a small amount (a few milliliters) of CSF for laboratory testing and/or measures CSF pressure. Patients often worry about spinal cord injury. I can reassure you that there is no need to fear during needle insertion, because at the site where CSF is collected only the terminal filaments of the spinal cord are present.

CSF examination is most commonly performed in neurology or infectious disease wards, and in some cases in intensive care units and neurosurgical departments.

Why a lumbar puncture is performed (indications) — when it is necessary

• Neuroinfections, i.e., infections of the nervous system, for example suspected meningitis of any origin (viral, bacterial, etc.), most commonly (neuro)borreliosis, tick‑borne encephalitis, herpetic infections.

• Exclusion of subarachnoid hemorrhage.

• Suspected demyelinating disease, e.g., multiple sclerosis; also autoimmune diseases such as Guillain–Barré syndrome; sarcoidosis, paraneoplastic syndromes, primary CNS tumors or metastases, etc.

• Assessment of intracranial pressure (to exclude idiopathic intracranial hypertension or hypotension).

• Therapeutic procedures — administration of certain drugs (spinal anesthesia, chemotherapy, intrathecal baclofen, antibiotics, contrast agents).

• Neurosurgical diagnostics, e.g., lumbar infusion test in certain types of hydrocephalus.

Contraindications — when it is not performed: high intracranial pressure (verified by other tests) or unconfirmed expansive intracranial processes, bleeding disorders, etc. Details on contraindications exceed the scope and educational purpose of this article for lay readers. Nevertheless, every physician considering CSF collection always excludes possible contraindications for each patient individually. It is essential that the patient fully informs the physician about all medications and supplements they are taking and about all medical conditions for which they are being treated.

How to prepare (practical)

The procedure is usually performed during hospitalization or in a designated outpatient clinic or day‑care unit of the healthcare facility (a hospital or clinic department). At the facility the patient will receive an informed consent form for lumbar puncture, which should describe why the procedure is being done, how it is performed, possible complications and recommendations for recovery.

Depending on local practice, either a standard needle or an atraumatic needle with a rounded tip is used for CSF collection. In obese patients a sufficiently long lumbar puncture needle must be used because the needle tip must pass through a substantial amount of fat and soft tissue before reaching the CSF space. In such patients a standard needle is usually chosen. At some centers the use of an atraumatic needle may incur an additional charge.

As a patient you have the right to read the informed consent calmly and to ask the physician performing the procedure any questions. In some cases, especially in life‑threatening situations when the patient is unable to give verbal or written consent, a lumbar puncture may be performed without the patient's consent (as with any necessary life‑saving procedure). There is no other noninvasive test that allows collection and laboratory examination of CSF. If you refuse the test, the physician will inform you of the risks and consequences of not being able to examine CSF in the laboratory, and everything will be documented in your medical record.

Before a planned lumbar puncture, usually several days beforehand, the patient should have blood tests to exclude contraindications to the procedure, e.g., low platelet count, coagulation disorders, etc. It is also necessary to undergo fundus (eye) examination or brain imaging (CT or MRI). The physician must be informed about all medications you take, especially anticoagulants. Usually these medications must be stopped or adjusted. In acute situations when CSF collection is performed urgently, all the above steps are carried out acutely during hospitalization.

On the morning of the procedure a light breakfast and nonalcoholic fluids are recommended. If you feel anxious, you may request a calming medication (anxiolytic) to be given before the lumbar puncture. Bring an adequate supply of nonalcoholic fluids, preferably drinks containing caffeine (cola drinks, coffee, strong tea) and still water/mineral water.

What is the difference between a standard lumbar puncture needle and an atraumatic needle?

An atraumatic needle has a rounded, blunter tip and therefore "parts" the puncture site (the dura mater) rather than cutting it, leaving only a very small opening. The procedure is gentler: when using a 24 G atraumatic needle the risk of post‑dural puncture headache is only about 2%. On the other hand, the needle may not be long enough in some patients or it may be necessary to switch to a larger‑diameter needle because the puncture and CSF collection may not succeed on the first attempt. A standard needle is usually slightly longer and has a sharp tip. It is sometimes advantageous in obese patients. Its drawback is a statistically higher risk of post‑puncture headache.

CSF collection procedure — step by step

• Blood tests just before the procedure. Immediately before the lumbar puncture blood is usually re‑drawn to refine laboratory comparisons between blood and cerebrospinal fluid.

• Patient position. You may sit on the edge of the bed or a chair with your legs down, sit cross‑legged, or lie on your side. The physician will instruct you on the correct position. Usually you will be asked to adopt a "cat's back" (flexed spine) posture in the lumbar region to widen the space between vertebrae for needle insertion.

• Aseptic technique. The procedure is performed under aseptic conditions to avoid introducing infection. The skin is disinfected and in most cases local anesthesia is not used; the patient remains fully conscious. The needle is inserted into the subarachnoid space between the 3rd and 4th or 4th and 5th lumbar vertebrae.

• Sensation during insertion. You may feel pressure in the lumbar area, and there may be radiating tingling, burning or shooting pain into one lower limb. The procedure is short (under 10 minutes). The physician may talk to you, instruct you on positioning and help distract you, especially if you are tense or anxious.

• When CSF flows. Once the needle is in place and CSF begins to drip into the collection tube, the main part of the procedure is essentially complete. The needle is then removed, a sterile gauze is applied and the puncture site is covered with adhesive.

• Post‑procedure positioning. You will be placed on the bed, first on your stomach and then on your back.

• Rest period. If an atraumatic needle was used, a minimum rest period of about 3–4 hours is recommended. If a standard needle was used, rest for at least 24 hours is usually advised.

• Multiple punctures. In some cases more than one puncture is necessary (for example because of spinal degenerative changes or a "dry tap" where no CSF is obtained at the chosen site). This can happen; physicians try to minimize trauma and ensure patient comfort during and after the procedure.

After the procedure — what is normal and when to call a doctor

• Normal findings. Local pain at the puncture site from soft‑tissue bruising or a small hematoma is common, especially after multiple punctures. Patients may feel tired. These symptoms usually resolve within a few days.

• Post‑dural puncture headache (PDPH). Occurs in approximately 2–4.2% of patients after atraumatic needle puncture (24–26 G) and about 11% after puncture with a standard needle. Symptoms begin 24–48 hours after the puncture and worsen in the upright position (sitting or standing) and improve when lying down. PDPH may be accompanied by neck stiffness, nausea, hearing or visual changes, and in some patients a fainting sensation. The headache is typically frontal or occipital. PDPH is caused by perforation of the dura mater with CSF leakage and subsequent intracranial pressure drop. With conservative treatment it usually resolves within 2 weeks, or sooner after closure of the defect with an epidural autologous blood patch. Risk factors include headache before or during the lumbar puncture and younger female age. Conservative measures: bed rest, adequate fluids, analgesics such as paracetamol or nonsteroidal anti‑inflammatory drugs, and caffeine. Epidural autologous blood patch (blood patch): the most effective interventional treatment for persistent post‑puncture syndrome; a small amount of the patient's own blood is injected into the epidural space to seal the defect and relieve pain.

• Warning signs. Severe headache, fainting, fever, bleeding, new neurological symptoms, marked pain or redness at the puncture site — contact the department where the lumbar puncture was performed or, in case of neurological symptoms or general deterioration, call emergency medical services (in the Czech Republic dial 155).

Do's and don'ts after a lumbar puncture

• Arrange for someone to accompany you and drive you home after the procedure, especially if it was performed on an outpatient basis.

• Avoid prolonged sitting or standing; do not bend or hyperextend your neck in the first hours and days after the puncture.

• Drink plenty of fluids — beverages containing caffeine are helpful (I do not recommend energy drinks); mineral water or plain water are also good. Aim for about 2 liters per day.

• Avoid smoking immediately after the lumbar puncture.

• Observe a period of relative rest even if you feel well immediately after the procedure (a few days of rest).

• Avoid strenuous physical activity and sports for several days.

Conclusion

Even in an era when humanity can send astronauts into space and medicine advances by leaps and bounds, no alternative method has yet been devised to obtain and examine cerebrospinal fluid other than lumbar puncture. This almost mythical procedure, which provokes panic in some patients fueled by numerous online patient discussions, is in fact a highly valuable diagnostic tool on which we rely for diagnosing many serious conditions. My aim with this short article was to provide information for patients directly from the "source," that is, from me. I do not perform lumbar punctures in my current clinic, but the procedures and recommendations described above remain valid.

Always check with the healthcare facility where your lumbar puncture will be performed about specific preparation and what to bring. If you have concerns or questions, direct them to the physician who will perform the procedure. A positive patient attitude helps both during the procedure and in the recovery period. The vast majority of patients who have undergone this procedure experience no serious complications or long‑term consequences, as shown by retrospective studies worldwide and by my own clinical experience.

"Most of the things we fear never happen." — paraphrase of Mark Twain.

MUDr. Petra Mištríková, MBA

References for further study:

Doherty CM, Forbes RB. Diagnostic Lumbar Puncture. Ulster Med J. 2014 May;83(2):93-102. PMID: 25075138; PMCID: PMC4113153.

Uppal V, Russell R, Sondekoppam R, Ansari J, Baber Z, Chen Y, DelPizzo K, Dîrzu DS, Kalagara H, Kissoon NR, Kranz PG, Leffert L, Lim G, Lobo CA, Lucas DN, Moka E, Rodriguez SE, Sehmbi H, Vallejo MC, Volk T, Narouze S. Consensus Practice Guidelines on Postdural Puncture Headache From a Multisociety, International Working Group: A Summary Report. JAMA Netw Open. 2023 Aug 1;6(8):e2325387. doi: 10.1001/jamanetworkopen.2023.25387. PMID: 37581893.