Headaches after lumbar puncture

This study looks at whether the position a child is placed in during a lumbar puncture (spinal tap) affects how much pain they experience afterward, particularly the type of headache that can sometimes follow this procedure. The study involves children who need lumbar punctures as part of their treatment for cancer. You may be eligible if: - Your child is between 4 and 15 years old - Your child is receiving treatment for a cancer and needs a lumbar puncture as part of their standard care - The procedure requires general anaesthesia and will be done in day surgery You may NOT be eligible if: - Your family needs an interpreter - Your child is having a bone marrow procedure on the same day - A specially trained doctor is not available - Your child needs an emergency lumbar puncture outside the day surgery unit - Your child already has a headache caused by a previous lumbar puncture Talk to your doctor about whether this trial might be right for you.