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BRIEF COMMUNICATIONS: M. Strupp, O. Schueler, A. Straube, S. Von Stuckrad–Barre, and T. Brandt "Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches Neurology 2001; 57: 2310-2312 [Abstract] [Full text] [PDF]

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Reply to Letter to the Editor

Michael Strupp, O Schuler and T Brandt   (3 May 2002)

"Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches

Klaus V Toyka, Bettina Muller and Heinz Reichmann   (3 May 2002)

"Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches

Axel Ellrodt   (28 January 2002)

Reply to Letter to the Editor 3 May 2002
Michael Strupp University of Munich Germany, O Schuler and T Brandt Send Correspondence to journal: Re: Reply to Letter to the Editor mstrupp{at}nefo.med.uni-muenchen.de Michael Strupp, et al.	We thank Toyka et al. for their comments on our study. Our originally submitted full-length manuscript cited the study of Müller et al. [1] as did also two of our previous publications. [2, 3] Their study had two methodological shortcomings. First, the diameter of the atraumatic needle was smaller (22 gauge) than that of the Quincke needle (20 gauge). Second, the orientation of the bevel was not mentioned. Since both factors influence the incidence of postlumbar puncture headaches (PLPH), they might explain the observed differences. Moreover, after evaluating all published studies, the "Therapeutics and Technology Assessment Subcommittee of the AAN on prevention of post-lumbar puncture headaches"7 concluded that "...the data [on the atraumatic needle] are conflicting in the diagnostic LP literature, but the studies have, in general, been inadequate to assess the question." A major aim of our study, therefore, was to consider all known methodological problems. Ad 1.: The methodological aspects of our study were originally given in detail, but the Brief communication form necessitated shortening all sections and reducing the references. Patients were randomized according to Efron before LP. A total of 306 patients underwent LP; 51 did not fulfill the inclusion criteria and were not randomized; 25 did not return the evaluation sheet. Ad 2.: The numbered evaluation sheets were unblinded only at the end of the study. A colleague who did not perform any LP in this study did the analysis of the data. Ad 3.: Patients were asked about headache before LP, and only those with no recent headaches, (i.e. at least up to one week before LP), were included and randomized. Ad 4.: The number of patients not returning the evaluation sheet did not differ between the two groups. Ad 5.: An introducer was used in both groups to minimize differences between the two needle types. Ad 6.: We stated that the two groups did not significantly differ; we did not claim that influence of these factors was excluded. Ad 7.: Our study was not designed to give new insights into the pathophysiology of PLPH. Ad 8.: The opening of the atraumatic and traumatic cannulas was kept identical, since (a) an effect cannot be excluded for the atraumatic cannula, (b) a double-blind design would have otherwise not been possible, and (c) the conditions in both groups remained as similar as possible. Our study differed from Müller study [1] in that (1) we used needles with an identical diameter in both groups and (2) the orientation of the needle bevels in both groups was parallel to the dura, as recommended by the AAN. References: 1. Müller B, Adelt K, Reichmann H, Toyka KV. Atraumatic needle reduces the incidence of post-lumbar puncture syndrome. J Neurol 1994;60:681-683. 2. Strupp M, Brandt T. Should one reinsert the stylet during lumbar puncture? [letter]. N Engl J Med 1997; 336(16):1190. 3. Strupp M, Brandt T, Müller A. Incidence of post-lumbar puncture syndrome reduced by reinserting the stylet: a randomized prospective study of 600 patients. J Neurol 1998; 245(9):589-592. 4. Evans RW, Armon D, Frohman EM, Goodin DS. Assessment: prevention of post-lumbar puncture headaches. Neurology 2000; 55:909-914.
"Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches 3 May 2002
Klaus V Toyka University of Wurzburg Germany, Bettina Muller and Heinz Reichmann Send Correspondence to journal: Re: "Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches kv.toyka{at}mail.uni-wuerzburg.de Klaus V Toyka, et al.	We read with interest the paper by Strupp et al. [1] The authors have largely confirmed (yet not cited) our double -blind controlled study on 100 patients [2] using the atraumatic cannula which was designed by Sprotte at this Medical School some years ago. [3] As the principal result of our study, the incidence of the post- lumbar puncture headache syndrome (post LPS) was dramatically reduced, even more so than described by Strupp et al. [1] In our subsequent "open label" - type use of the Sprotte cannula it became clear that post LPS is further reduced with continuous practice. [4] We have a number of concerns with the study design and the interpretation of data: 1) It is not indicated how exactly and at what time the randomization of patients took place during their hospital stay nor is it clear how many patients were actually randomized. The numbers are given only for the patients "included in the final analysis". There is also no stratification for nor an account on disorders which in them are prone to cause headache. 2) The evaluation sheet given to patients for eligibility to participate in the study seems to have included items that were only available post lumbar puncture such as coffein intake post LP and medication post LP. This could potentially unblind the evaluating physician who is, upon knowing the results from other studies and ours, likely to be biased towards an advantage for the atraumatic needle. 3) In the questionnaire provided after randomization the patients were asked about previous headache yet this should have excluded them from being randomized in the first place. It is unclear when the patients were questioned about suffering from previous headache. 4) The authors state that patients were not included in the study if they did not return the evaluation sheet. According to pertinent nomenclature these patients would be rated as included in the study but excluded from the evaluation; in an intention-to-treat study these patients would have to be evaluated. This may be clarified. 5) The authors state in Methods that all LP was performed by "experienced neurologists who were unaware of the type of the needle". How can blinding be obtained if the atraumatic needle is (a) much more prone to bending and (b) the resistance that is to overcome when punching through the ligaments and dura is so much higher than with the sharp and stiffer Quincke needle (cf. fig.1 of the paper)? Only inexperienced neurologists would not realize the difference. 6) The authors state that several group comparisons did not reveal significant differences and go on to claim that this excludes an influence of these factors on the study result. This kind of conclusion is not substantiated by the set of data presented (ß - error). 7) The type of evaluation for post LPS as done by Strupp et al. falls short of giving new clues as to the underlying pathogenesis. The leakage (liquorrhea) hypothesis, which they propose, is at variance with our findings. In our study we saw a higher number of immediate symptoms and signs that may be related to autonomic nervous system reactions in those patients who later developed post LPS. It is unlikely that CSF leakage could account for this. 8) Strupp et al. propose that the circular position of the side opening of the atraumatic cannula may be important for the frequency of post LPS. Since this needle does not cut through the longitudinal ligaments and the dura but rather spreads its filaments apart it is not clear how the orientation of the burr hole might bear on post LPS. References: 1. 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;57:2310-2312. 2. Müller B, Adelt K, Reichmann H, Toyka KV. Atraumatic needle reduces the incidence of post-lumbar puncture syndrome. J Neurol 1994;60:681-683. 3. Sprotte G, Schedel R, Pajunk H. Eine "atraumatische" Universalkanüle für einzeitige Regionalanästhesien. Reg Anaesth 1987;10:104-108. 4. Toyka KV. Postlumbar puncture headache. J Neurol Neurosurg Psychiat 1997;62:429 (letter to the editor).
"Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches 28 January 2002
Axel Ellrodt, Emergency Physician American Hospital of Paris Send Correspondence to journal: Re: "Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches axel.ellrodt{at}wanadoo.fr Axel Ellrodt	The authors mention that previous studies do not take into account the direction of the needle bevel nor the stylet replacement when comparing traumatic and atraumatic needles. The authors explain in the Methods section that biases were indeed controlled. However, it does not mention what was done to control for bevel direction and stylet pre-withdrawal replacement or if local anesthesia was given. As a former heavy user of Quincke needles and a strong supporter of "atraumatic" needles, I also wonder how experienced neurologists may have been ignorant of the type of needle used. If kept blind to it, how they could they ascertain that the bevel direction with Quincke needles was optimal for fair comparison with atraumatic needles? Was the needle oriented by somebody else ?