Information for patients - Lumbar Puncture

Cork Emergency Departments

Lumbar puncture is an important investigation to help confirm a diagnosis or treatment options. In most cases your doctors are trying to exclude a bleed / stroke or confirm meningitis. As with any investigation, there are possible side effects, most listed below.

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This occurs in up to 10% of patients and typically starts within 1 to 2 days of the LP. Symptoms are always worse when standing up and characteristically significantly eased by lying down. If you experience a post-LP headache you should lie down as much as possible and rest. You need to keep drinking plenty of fluid. Painkillers should not be needed if you stay flat most of the time.

Infection / fever

Infection may very rarely be caused whenever a needle has punctured the skin. This is minimised by cleaning the area before the procedure and by good hygiene practices. If you become feverish following a LP you should seek medical attention from your doctor or emergency department.

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Backache can occur in up to a third of patients. It is almost always mild and settles over a few days. Simple painkillers such as paracetamol may be helpful but should be limited to just a few days.

Dermoid formation

Occasionally where the LP needle has been introduced you may develop a small lump in the skin.

Risk of Bleeding

With a LP there is a risk of bleeding occurring (subarachnoid or epidural haemorrhage). This risk is increased if you are on anticoagulants such as heparin or warfarin or if you have a bleeding disorder. If you have not already mentioned any of these problems to the medical team on this occasion please make them aware before they carry out the LP.

Risk of eye nerve damage

Extremely rarely a cranial nerve (VI) that controls eye movements may be damaged following an LP. This may result in double vision. This may be temporary or permanent.

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Risk of pressure cone

This again is an extremely rare complication and will happen when there is a mass in either your spine or head area. For this reason if you have evidence of this a CT brain scan will usually be done before you have an LP to make sure it is a safe as possible to proceed.

Dr Arthur Jackson (Consultant Infectious Diseease), Dr Íomhar O' Sullivan, Consultants in Emergency Medicine. Last review Dr IOS 17/06/21.