Talk:Lumbar puncture
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I think its worth noting in the procedure section that the lumbar puncture must also penetrate the arachnoid. - JRS —Preceding unsigned comment added by 155.58.11.16 (talk) 21:29, 12 June 2008 (UTC)
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[edit] Question
How long do the headaches last after a spinal tap has been done?
- Hours to days, depending on the speed by which the CSF was drained. Some people keep on "seeping" CSF into their epidural space; they sometimes require a "blood patch" to stop this; the headaches resolve almost instantly. JFW | T@lk 07:41, 7 Feb 2005 (UTC)
[edit] Complication of LP
The article says, 'Some authorities believe that withdrawal of fluid when initial pressures are too low could result in spinal cord compression or cerebral herniation...' Cerebral herniation is accepted in standard texts as a well known complication of raised intracranial pressure which may occur with space occupying lesions in the brain. If what the article claims is well researched, it should be presented as an adjunct to this fact which surprisingly doesn't find a mention.
- I'm the author of the text you quoted. I can't tell whether your criticism is because you think it's obvious that LP can cause cerebral herniation, or because you think it's obvious that LP could never cause cerebral herniation and that it must always be due to the presence of space-occupying lesions in the brain and never due to LP. -Ikkyu2 02:58, 30 December 2005 (UTC)
- Oh, I see what your deal is. It's not whether the LP is causative, but the phrase "initial pressures too low." The idea is that in obstructive hydrocephalus the spinal pressure is significantly lower than the above-obstruction pressures, and that lowering it further can worsen the pressure gradient and cause herniation. Not everyone believes this, and even the 'too low' measured pressure is usually higher than normal in this model. I will modify the statement to weasel around this and please everyone, regardless of their interpretation of the Monroe-Kellie doctrine. -Ikkyu2 03:02, 30 December 2005 (UTC)
Why is it that this article is completely devoid of any acknowledgment of the risks of shift? That is to say, the dangers of someone having a suspected space-occupying lesion in the brain prior to the tap, which can then cause the brain to "shift" into the growth causing fatal complications. - April 4 2006
- The article is still devoid of this. Some studies say that neuroimaging is only required if there is a suspected mass lesion, while other recommend it in focal signs, decreased level of consciousness or signs of raised ICP (papilloedema, decerebrate positioning etc.) I personally have never seen any junior doctor in the UK do an LP without a CT scan, probably because they are easy to obtain in patients whose history is bad enough to warrant an LP. JFW | T@lk 13:14, 21 January 2008 (UTC)
[edit] Trivia?
Since one can never be sure of the reasons that a reader might be searching for this article, I wonder if it might be worthwhile to include a mention of the urban myth that spinal taps are "routinely" performed to determine if someone has used LSD. Perhaps a brief mention in a newly added "Trivia" section would be in order. - Ugliness Man 11:24, 23 February 2006 (UTC)
[edit] Most painful thing ever
I heard someone on the radio say that a lumbar puncture is the most painful thing in the world ever... exactly how painful is it? --124.180.103.210 09:55, 25 June 2007 (UTC)
- Child birth? —Preceding unsigned comment added by 71.86.54.3 (talk) 05:44, 29 March 2008 (UTC)
I'm pretty sure if you had a lumbar puncture done you would be sufficiently numbed up so that you couldn't feel it, otherwise you could jerk and be paralyzed.
I've been told that no anesthetics can be used, as they will distort the composition of the fluid. I sincerely hope that I will never have to undergo such a thing, though. --74.132.11.37 23:01, 7 August 2007 (UTC)
--I have had a lumbar puncture when it was suspected I contracted meningitis. It was forbidden to administer any anesthetic/numbing medications as that will contaminate the sample and/or mask symptoms. Also... if you're sick enough, and of the type, to need a lumbar puncture, giving you drugs that affect your nervous system is probably a bad idea.
How painful was it? Yes, I can safely say it was the most physically painful thing I've ever experienced. Even though I was only 13, I needed several nurses/orderlies to pin me down when they drew it.
So here's how I (poorly) describe the pain of the experience: You ever wonder if there is a centre to your body, like a core or a column that runs right down the middle? I don't mean the spinal column, I mean more like a metaphysical, hard to describe, centre of your being. Now also think of all the nerves in your body, from deep inside you to the very extremes of your body - your fingertips, the soles of your feet, your scalp.
When the lumbar needle (which feels as thick as coat-hanger wire, btw) gets tapped in, it's like someone pounding a nail into the wall to hang a picture. Except that wall is your soul. Every nerve, every cell, every ounce of your being rings and trembles like it's been hit by a sledgehammer... it's electrifying. In an instant you can feel the whole totality and mass of your body. It's not like being hit in a fight, struck by a car, or falling. This pain comes from deep inside you and radiates outwards.
Once it's in and they're drawing the CSF, it ain't so bad. I couldn't tell you about the headaches afterwards, since it wasn't too long after that I started convulsing and hallucinating.
- It sounds awful. But how certain are you that no local anaesthetic was used? Lidocaine, when injected under the skin, gives a pretty nasty burning sensation that precedes the numbness. JFW | T@lk 13:14, 21 January 2008 (UTC)
[edit] Local anesthesia for LP and the "give" entering the dura mater
1) Local anesthesia with lidocaine is standard procedure for an LP. It should never be performed without this, and lidocaine is included in all lumbar puncture kits that I have seen. I wonder what year the incident occurred in which the man writing below (above, comment was moved JFW | T@lk) had an LP without anesthesia - if it wasn't a very long time ago then he has grounds for a lawsuit. 2) I believe that the "give" which the author refers to in the procedure section is the needle puncturing the ligamentum flavum just before entering the dura mater. —Preceding unsigned comment added by 128.252.16.235 (talk) 14:20, 26 September 2007 (UTC)
- Thanks. I agree that LP without analgesia is not of this day and age. Mind you, the lidocaine does not actually mix with the CSF. All it does is dull the nerve endings of the skin and subcutaneous tissues.
- Everyone always says that the "give" is the penetration of the dura. Having done my own bunch of LPs I can definitely identify with its description. JFW | T@lk 13:14, 21 January 2008 (UTC)
