Is a Lumbar Puncture Really that bad?
Each year almost a million people worldwide will have to have a lumbar puncture (or spinal tap) test performed. A lumbar puncture (also called LP) is a test where a needle is put into the lower back to obtain a sample of fluid called cerebrospinal fluid (or CSF). The usual reason for the test is to investigate a sudden onset headache such as suspected meningitis or subarachnoid haemorrhage (a type or brain haemorrhage). It can also be used to investigate other headaches such as the one caused by raised pressure within the skull - idiopathic intrancranial hypertension. Lumbar puncture has a notorious reputation, and while any medical procedure can be uncomfortable, why is this particularly true for LP?
LPs were first performed in the late 1800, by an Englishman called Wynter in 1889, although Quincke - a German physician - is most widely creditied with the first LP in 1890. These first LP tests were performed in children with a very grave illness called TB meningitis. Many of these first LP cases died from their disease - it is easy to see how LP could get a bad reputation. Even until relatively recently, an LP was seen as a test which could be performed at the bedside by fairly inexperienced doctors, and training in LP has been poorly organised - there is an old phrase (now discredited) called see-one - do-one - teach-one. There is no doubt that an experienced person will be much more likely to perform a skilled and relatively painless LP. If most people’s experience of LP is performance by a very junior doctor the bad reputation can only be re-inforced.
To get a better picture of the reality of performing and experiencing a LP you shold ask people who have had several LPs or speak to experienced LP operators. Idiopathic Intracranial Hypertension is a rare condition causing headaches and impaired vision due to high pressure of cerebrospinal fluid within the nervous system. People with IIH often need many LPs to relieve the pressure and prevent visual problems. Here’s a quote from one patient:
“I was really nervous about it, they caught a nerve but i told them and they moved the needle, it was a bit uncomfortable lying in the same position for 2 and a half hours while they drained me, but then afterwards my back ached for a while and the next day it felt like when you have a bruise, but then I was ok”
Maybe this doesn’t seem too bad. Note how she was nervous and I’m sure not knowing what to expect is part of the reason for the bad experiences reported by many. Another IIH sufferer has had over 15 LPs (another says she has stopped counting!) I think it is interesting to note that not being prepared mentally may have contributed to her discomfort:
“I have had about 15 + LP’s. The first one hurt but I think that was because I was so tense and didn’t know what to expect. I apologise to those reading this who have a bad time but after that first one I had no problems at all and was fine about having them. I only ever had the expected discomfort of that sort of tugging in your back but that’s it”
While the actual LP may not be that bad, the most feared complication is a bad post-lumbar puncture headache (or spinal headache). In an LP a small hole has been made in the base of the contained that holds brain and spinal fluid. This contained called the meninges will usually seal spontaneously. In some the seal does not occur, and CSF continues to leak out into the spine. This causes a drop in pressure, and means that the brain is no longer supported by a normal amount of CSF. In reality the brain is rattling around in the head causing irritation to the meninges and creating a severe pain, which is a lot worse when standing and is only relieved by lying flat. Not knowing that this may occur is another cause for distress.