by Richard Hughes and Claudio Bassetti
Most neurologists used to carry out few practical procedures beyond the neurological examination which one of us has already discussed in this Forum (https://www.eanpages.org/?p=1443). This is changing. Some undertake diagnostic procedures such as electrophysiology, ultrasonography, nerve, muscle and now skin biopsies. Others undertake thrombolysis for stroke, corticosteroid injections for carpal tunnel syndrome and botulinum toxin injections for dystonia. In some countries neurologists, challenging the neuroradiologists, take on interventional neuroradiology. However there is one procedure which we have all done and many continue to do — the lumbar puncture, first introduced in 1891 by Professor Quincke (chair of internal medicine, first in Bern and later Kiel).
A paper in the February edition of the European Journal of Neurology* calls attention to a lamentable lack of attention to the advantages of using an atraumatic needle, at least in England [1]. Davis et al. at the Royal London Hospital performed lumbar punctures on 52 patients with traumatic 22G Quincke needles and then changed their practice and used atraumatic 22G Sprotte needles on 57 further patients. Assessment by a blinded assessor after 7 days identified a reduction in the number of patients with post lumbar puncture headache from 29 of 48 patients to 13 of 48 eligible patients, risk difference 33% (95% confidence interval 15 to 52%). The atraumatic needles cost much more but a cost analysis showed that their use resulted in savings because of the reduction in the costs of treatment of post-lumbar puncture headache. Of course, the study was an audit and had many problems which reduce confidence in the conclusions to be drawn, not least the lack of randomisation and the possibility that the investigators had become more skilful during the second study period.
In a randomised trial with a low risk of bias involving 230 patients, the incidence of post lumbar puncture headache was halved with the atraumatic needle, 12.2%, compared with the traumatic needle, 24.4%, risk difference 12% (95% confidence interval 2% to 22%) [2]. Despite conflicting results in two previous smaller and less rigorous randomised studies [3;4], this evidence and additional comparisons in the anaesthetic setting were sufficient to persuade the American Academy of Neurology Committee to recommend the use of traumatic needles for diagnostic lumbar punctures. The American recommendation is based on European data so that the Presidential advice is to prefer the atraumatic needle and to re-insert the stylet before removal of the needle. This is because, in another useful trial on 600 patients, reinsertion of the stylet into the atraumatic 22G Sprotte needle before its removal reduced the incidence of post-lumbar puncture headache by two thirds from 16.3% without reinsertion to 5.0% with reinsertion (risk difference 11.0%, 95% confidence interval 6% to 16%) [5].
It is fair to say, however, that issue remains a bit controversial; despite the obvious advantage of a smaller needle in terms of post lumbar puncture headache, some studies have challenged the notion of an overall advantage of the atraumatic needle [6] [7]. Its use does require more experience; it may introduce a greater risk of local injury and the duration of the procedure is longer. These and other considerations led the German Neurological Society (DGN) in their guidelines to restrain from definite recommendations concerning the type of needle to be used for lumbar puncture (DGN, Leitlinien Diagnostische Liquorpunkttkion, 2012). The matter could be resolved by a larger, Europe-wide, audit and sealed by an evidence-based European guideline, a suggestion to the incoming European Academy of Neurology officers.
References
1. Davis A, Dobson R, Kaninia S, et al. Change practice now! Using atraumatic needles to prevent post lumbar puncture headache. European Journal of Neurology 2014;21:305-12.
2. Strupp M, Schueler O, Straube A, Von Stuckrad-Barre S, Brandt T. “Atraumatic” Sprotte needle reduces the incidence of post-lumbar puncture headaches. Neurology 2001;57:2310-2.
3. Braune HJ, Huffmann GA. A prospective double-blind clinical trial, comparing the sharp Quincke needle (22G) with an “atraumatic” needle (22G) in the induction of post-lumbar puncture headache. Acta Neurol Scand 1992;86:50-4.
4. Lenaerts M, Pepin JL, Tombu S, Schoenen J. No significant effect of an “atraumatic” needle on incidence of post-lumbar puncture headache or traumatic tap. Cephalalgia 1993;13:296-7.
5. 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;245:589-92.
6. Sharma SK, Gambling DR, Joshi GP, Sidawi JE, Herrera ER. Comparison of 26-gauge Atraucan and 25-gauge Whitacre needles: Insertion characteristics and complications. Can J Anaesth 1995;42(8):706-10.
7. Popp J, RIad M, Freymann K, Jessen F. Ambulante Durchführung einer diagnostischen Lumbalpunktion in der Gedächtnissprechstunde. Der Nervenarzt. 2007:78(5): 547-551.
* the European Journal of Neurology, which the EFNS owns, will be the journal of the future European Academy of Neurology: the transition task force had wanted to change the name to mark the change in governance as the EFNS and ENS came together but such a change would have lost the impact factor which has been built up to over 4 under the editorship of Professor Tony Schapira.
