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Reinsertion of the stylet prior to needle removal in diagnostic lumbar puncture

Three Part Question

In [patients undergoing diagnostic lumbar puncture] does [reinsertion of the stylet prior to needle removal] [reduce the incidence of post-lumbar puncture headache]?

Clinical Scenario

A 31-year-old female presents to the emergency department with a sudden onset severe headache. After a normal head CT, you prepare for lumbar puncture with a small gauge non-traumatic needle. You remember a colleague telling you it is also important to replace the stylet before removing the needle to prevent a post-lumbar puncture headache. You wonder what is found in the literature.

Search Strategy

Medline 1966 to 09/04 using OVID interface and The Cochrane Library, Issue 3, 2004 via the NeLH.
Medline: [exp spinal puncture OR (spinal adj5 tap).af OR (spinal adj5 puncture).af OR (spinal adj5 injection).af OR (lumbar adj5 tap).af OR (lumbar adj5 puncture).af OR (lumbar adj5 injection).af OR (dural adj5 tap).af OR (dural adj5 puncture).af OR (dural adj5 injection).af] AND [exp headache OR exp headache disorders OR headache.af OR post-lumbar puncture syndrome.mp OR PDPH.mp OR PLPS.mp] AND [needle.mp OR exp needles OR stylet.mp] LIMIT to human AND English language.
Cochrane: [lumbar] next [puncture]

Search Outcome

Altogether 235 papers found, 2 of which addressed the three part question (same article published as correspondence then full study) (1,3). No additional references were found in the Cochrane database.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Strupp M et al,
1998,
Germany
600 neurology patients undergoing diagnostic LP randomly assigned (patient blinded) 300 to stylet replacement before needle removal, other 300 not reinserted. Similar sex and age. Used 21G atraumatic needleProspective Randomized Controlled TrialPost-lumbar puncture syndrome (headache, tinnitus, dizziness) reproducible by position and improved laying down, over 7 daysNot reinserted 49/300 (16%) post lumbar puncture syndrome vs. 15/300 (5%) when stylet reinserted. Post Lumbar Puncture Syndrome was also less severe (2.8 vs. 4.5 scale of 10) if stylet reinsertedExcluded patients with headache prior to LP PLPS intensity scale not clearly defined Follow up not clearly described

Comment(s)

The theory is when CSF is removed, strands of arachnoid enter the needle. When the needle is removed, the strand may then be threaded back through the dural defect and produce prolonged CSF leakage resulting in the post-lumbar puncture syndrome. This was postulated on the observation that the post-lumbar puncture syndrome is much lower after spinal anesthesia than after diagnostic lumbar puncture. Replacing the stylet would then push out or cut off any strand of arachnoid. The authors also rotated the needle 90 degrees prior to removal (2). This is the only study performed looking at replacing the stylet. Some aspects of the study are not clearly described randomization, intensity scale, follow up. Nevertheless, there appears to be minimal risk and likely benefit in replacing the stylet prior to removing the needle.

Clinical Bottom Line

Replacing the stylet before removal of the spinal needle may help decrease the incidence of post-lumbar puncture headaches.

References

  1. Strupp M, Brandt T, Muller A. Incidence of post-lumbar puncture syndrome reduced by reinserting the stylet: a randomized prospective study of 600 patients. J Neurol 1998;245(9):528-29.
  2. Strupp M, Brandt T. Should one reinsert the stylet during lumbar puncture? N Eng J Med 1997;336(16):1190.
  3. Evans RW. Complications of lumbar puncture. Neurol Clin 1998;16(1):83-105.