After intrathecal chemotherapy

Intrathecal chemotherapy is given into the cerebrospinal fluid, the clear fluid that surrounds the brain and spinal cord. To reach it, a doctor performs a lumbar puncture, passing a fine needle between the bones of the lower back into the space containing the fluid. A small amount of fluid is often removed for testing, and the chemotherapy is injected. Afterwards, a tiny hole remains in the protective membrane around the spinal cord. In some people, fluid slowly leaks out through this hole for a short time. When fluid pressure around the brain drops, the brain sags slightly when you sit or stand, stretching sensitive structures and causing a headache. This is called a post-lumbar puncture headache.

The typical pattern is a headache that is worse when sitting or standing and eases when lying flat, sometimes with neck stiffness, nausea, dizziness or sensitivity to light. It often starts within a day or two of the procedure and usually settles on its own within days as the hole seals. This is why many teams advise lying flat for a period after a lumbar puncture, drinking plenty of fluids and taking simple pain relief such as paracetamol, although evidence on how long lying flat helps is mixed and instructions vary. The instruction is rarely explained, so people either ignore it or worry that something has gone wrong. If a headache is severe, lasts more than a few days, or comes with fever, confusion, weakness or other worrying symptoms, it needs prompt review, because other rarer problems such as infection or bleeding must be ruled out.

Caffeine may help some people

A cup of tea or coffee is sometimes suggested for mild headaches. Ask your team whether it is suitable for you.

A blood patch is sometimes used

For persistent severe headaches, an anaesthetist may inject a small amount of your own blood near the puncture site to seal the leak.

Children may show it differently

Young children may be irritable, vomit or refuse to sit up rather than describe a headache.

It cannot tell you exactly how long you should lie flat or how long a headache will last. Hospital practices vary, and individual recovery differs. Follow the instructions your team gives you.

It also cannot tell you whether a headache is a simple post-puncture headache or a sign of something more serious. Severe, unusual or worsening headaches need assessment.

Low platelets

Lumbar punctures are planned when platelets are safe, as low platelets increase bleeding risk.

Blood thinners

Tell your team if you take blood thinners before any lumbar puncture.

Repeated procedures

Some treatment plans involve many lumbar punctures. Tell your team if headaches have been a problem before.

Anxiety about the procedure

Numbing medicine, sedation for children and clear explanations make lumbar punctures easier.

Safety checks

Before any spinal injection, staff check the medicine and route carefully. You can ask about these checks.

Travel after the procedure

Long journeys sitting upright straight after a lumbar puncture may worsen headaches. Plan to rest first.

Return to activities

Avoid heavy lifting and strenuous activity for a day or two, or as advised.

Children

Children may need comfort, fluids and quiet rest after the procedure.

Why intrathecal chemotherapy is given

Some cancers, especially certain leukaemias and lymphomas, can spread to or hide in the fluid around the brain and spinal cord. Most chemotherapy given into a vein or by mouth does not cross easily into this fluid, because the brain is protected by a barrier that keeps many substances out. Giving medicine directly into the spinal fluid bypasses this barrier, allowing treatment to reach cancer cells there, or to prevent cancer from spreading there. For children and adults with some blood cancers, intrathecal treatment is a routine and important part of the plan, often given many times over the course of treatment. Understanding its purpose can make repeated lumbar punctures easier to accept.

Preparing for a lumbar puncture

Before the procedure, your team will check blood counts and platelets, ask about blood thinners, and explain what will happen. You will usually lie on your side curled up, or sit bent forward, so the spaces between the bones open. The skin is cleaned and numbed with local anaesthetic, and children may be given sedation. Staying still helps the procedure go smoothly. Telling staff if you feel anxious, or if a previous procedure was painful, allows them to offer extra support.

Looking after yourself in the following days

In the day or two after a lumbar puncture, avoid heavy lifting, strenuous exercise and long periods upright if headaches start. Keep the small dressing clean and dry, and remove it when advised. Continue drinking fluids. Most people return to normal activities quickly, but listen to your body and rest if you need to.

What to do next

Ask how long to lie flat and when to resume activities, drink fluids, use simple pain relief as advised, get up slowly, plan rest before travel, and seek help promptly for severe or persistent headache, fever, weakness or confusion.