X-ray Guided Lumbar Puncture

A lumbar puncture (LP) is performed to gain access to the CSF (cerebrospinal fluid) spaces in the spinal cord in order to obtain CSF samples for laboratory testing or to drain off fluid to reduce elevated pressure within the CSF system.

X-ray guidance is used to more easily visualise the bony anatomy of the spine and spaces between, where a spinal needle will be placed. You may have had previous attempts on the ward at lumbar punctures, which were unsuccessful due to difficulty in accessing the thecal sac (space that contains CSF around the spinal cord).

The information obtained from CSF sample testing can help to make a diagnosis or to plan your further treatment.

All treatments and procedures have risks and we will talk to you individually about the risks of X-ray guided lumbar punctures and the use of X-rays in your diagnosis and treatment plan.

Problems that may happen straightaway

Some stinging may occur when the local anaesthetic is being injected. However, this is only momentary.

There may be some short-lived discomfort when the lumbar puncture needle is being positioned correctly.

There is low probability that you may feel some discomfort when CSF is drained - for example, a headache or ache in the back or down your legs.

Problems that may happen later

Some people experience a headache immediately after or within a day or so of the lumbar puncture. This is common and can be relieved by simple painkillers such as paracetamol. Drinking plenty of fluids reduces the risk of headache and will also help to relieve it.

Problems that are rare, but serious

Whilst serious complications remain very unlikely, they may include:

• nerve root damage
• meningitis
• epidural abscess
• CSF leak or haemorrhage.

Radiation Risk

Like all x-ray machines, equipment used during your lumbar puncture produces x-rays which can potentially be harmful and may cause some cancers to develop in the future. Modern equipment and techniques are designed to keep the x-ray exposure as low as possible whilst producing some exceptionally clear images of your body. In addition, your doctor will have made a judgement about your risk and benefit before agreeing to the scan (including the risk to your health of not having the procedure). The dose of radiation for each procedure can be compared to the amount of background radiation that you will receive just by living in the UK. The amount you receive will depend on the type of scan/ procedure you are having. For example, a CT scan of the head will be the same as receiving an additional 12 months of natural background radiation. A lumbar puncture under X-ray guidance will result in receiving much less radiation that a CT head scan.

Female patients of childbearing capacity between the ages of 12 and 55 years are required by law to be asked about possible pregnancy when undergoing examinations involving x-ray to the abdomen. Patients who either are, or think they may be, pregnant must inform the Neuroradiology Department as soon as possible. In some urgent cases the scan may still go ahead but with additional precautions in place. To reduce the risk for early and unknown pregnancies, X-ray guided lumbar punctures are usually performed within the first ten days of the menstrual cycle when pregnancy is much less likely.

The Neuroradiologist will discuss all possible risks with you and give you the opportunity to ask questions.

The decision whether or not to have this diagnostic examination is entirely yours. To decline the procedure will not affect your personal care. However, it may mean that your consultant cannot be as certain or specific about any future treatment or procedures and it may affect some clinical decision making.

Your referring consultant will discuss alternative investigations with you, including their risks and benefits. These may include a lumbar puncture without X-ray guidance, blood tests or other scans or diagnostic tests.

You may be asked to attend pre assessment clinic before your admission, this is so we can take blood tests and ensure you are prepared for the procedure.

You will be admitted to hospital on the morning of the procedure, you will be informed which ward to attend by the admission officer in contact with you. A member of the nursing staff on the ward will complete an admission checklist with you and give you an identity bracelet to wear whilst you are in hospital. You will be offered a hospital gown or you can bring your own loose, comfortable clothing if you prefer. All jewellery and hair clips should be removed.

We will ask you about all of the medicines you are taking especially anticoagulants such as warfarin or heparin, or antiplatelet agents such as aspirin, clopidogrel or dipyridamole. These medicines may need to be stopped before your procedure. If they are not, your procedure may not go ahead.

Please inform your clinical team if you take any anti-coagulants or anti-platelets. The clinical team organising your admission will advise you to stop medications in advance. Please do not stop taking any medicines unless you have been specifically advised to do so.

On the day of the procedure, you can eat and drink normally and take all of your usual medications, except for those mentioned above. It is advisable to be well hydrated prior to this test.

We want to involve you in all the decisions about your care and treatment. If you decide to go ahead with treatment, by law we must ask for your consent and will ask you to sign a consent form. This confirms that you agree to have the procedure and understand what it involves. Staff will explain all the risks, benefits and alternatives before they ask you to sign a consent form. If you are unsure about any aspect of your proposed treatment, please don’t hesitate to speak with a senior member of staff again.

The nurse caring for you will escort you from the ward to the angio suite within the Neuroradiology department for your test.

A Neuroradiologist (radiology doctor) will explain what will happen and answer any additional questions you may have. We will ask you to lie on the examination table either on your front or on your side.

The Neuroradiologist will clean the skin and a local anaesthetic will be is injected to numb the area. A fine needle is inserted into the fluid-filled space below the spinal cord. X-rays are taken to help position the needle correctly. During this part of the procedure a small amount of cerebrospinal fluid may be drained off and sent to the laboratory for analysis.

If the aim of the procedure is to reduce elevated CSF pressure, then the Neuroradiologist will attach a measuring pipette to the spinal needle and measure the ‘opening pressure.’ A certain quantity of CSF will then be drained off to return the CSF pressure to a normal range where a second ‘closing pressure’ will be taken before removing the spinal needle.

Upon removal of the needle from your back, a small dressing will be placed to cover the area and you will be asked to lie flat on your back.

After the procedure you will be taken back to the ward. On the ward you must remain in bed for two to three hours. You may have your head slightly raised. Drinking plenty of fluids is advised.

You will not normally be required to stay overnight unless further delayed imaging is required, or other investigations have been arranged for you during your admission. You can resume normal day-to-day activities after discharge.

The Neuroradiologist who performed the procedure will write a report to your referring doctor, who will discuss the test results with you at your next consultation.

If you experience any of the following you should contact your GP or go to the nearest Accident and Emergency Department straight away:

• severe headache which is not relieved by over-the-counter medicine or which lasts longer than 24 hours
• drowsiness
• fever
• new symptoms such as weakness or numbness in your limbs
• difficulty passing urine or moving your bowels
• dizziness
• discharge of blood or fluid from the injection site in your back.

• NHS Direct is a useful source of health information.
• The Brain & Spine Foundation UK
  Telephone: 0808 808 1000
• Idiopathic Intracranial Hypertension UK

UCLH cannot accept responsibility for information provided by other organisations.

Lysholm Department of Neuroradiology

National Hospital of Neurology and Neurosurgery, Queen Square, London, WC1N 3BG

Email: ulch.enquiry.nhnmrapp@nhs.net

Direct line: 020 344 83444

Switchboard: 0845 155 5000 / 020 3456 7890

Extension: 83444 / 83440

Fax: 020 344 84723

Website: www.uclh.nhs.uk/nhnn

The Lysholm Department of Neuroradiology reception is located in Chandler wing, on the lower ground floor of the National Hospital for Neurology & Neurosurgery, Queen Square.

Please turn left when you exit the chandler wing lifts on the lower ground floor to find our main departmental reception.