1994, The British Journal of Radiology, 67, 396-398 Technical note: The influence of using an atraumatic needle on the incidence of post-myelography headache 1 M J JONES, MRCP, FRCA, 1 I R SELBY, FRCA, 1 C L GWINNUTT, FRCA and 2 D G HUGHES, MRCP, FRCR Departments of 1 Anaesthesia and 2 Radiology, Hope Hospital, Eccles Old Road, Salford M6 8HD, UK Abstract The aim of this study was to investigate whether the incidence of headaches following myelography could be reduced by using a needle with an atraumatic tip. 107 patients were studied in a trial of 22 gauge atraumatic versus 22 gauge bevel tipped needles. In the first 3 days after myelography, there was a significant reduction in the incidence of headaches in patients in whom an atraumatic needle had been used. It has long been recognized that following myelo- graphy, a significant number of patients complain of a headache [1]. The headaches are variable in nature but are characteristically aggravated when upright, eased by lying down and may be accompanied by a feeling of nausea. Unsteadiness on walking and vertigo occur in some patients [2]. It has been suggested that this pheno- menon is in part due to continued leakage of cerebro- spinal fluid (CSF) through the hole made in the dura by lumbar puncture. Studies have demonstrated a correla- tion between the diameter of needle used and the inci- dence of headache [1,3]. A similar syndrome is well recognized in patients undergoing spinal subarachnoid anaesthesia [4], although the incidence of headache is lower than after myelography. Recently, a new design of needle with an atraumatic conical tip, the "Sprotte" needle (Rusch UK Ltd, High Wycombe), has been introduced for spinal anaesthesia (Figure 1). This has been shown to be associated with a significant reduction in the incidence of post-spinal headaches when compared with bevel tipped needles [5, 6]. The present study was undertaken to see if a reduction in the inci- dence of headaches could be achieved, comparing an atraumatic needle with a bevel tipped needle of the same diameter for lumbar puncture, during myelography. Patients and methods Following Ethical Committee approval, both in- patients and day-case patients were studied. On the basis of their hospital number, patients were random- ized into two groups; Group 1 (even numbers) to have myelography using a 22g atraumatic needle, Group 2 (odd numbers) using a 22g bevel tipped needle. A record was made of the extent of the examination and the result of the myelogram. All patients were followed up Received 23 April 1993 and in revised form 25 August 1993, accepted 12 October 1993. Address correspondence to Dr Carl Gwinnutt. for 3 days to ascertain the incidence of headaches. Inpatients were visited by a member of the anaesthetic department and day-case patients were given a question- naire, which they were asked to complete and return. Patients operated upon within 24 h of their myelogram were excluded from the study. The combined effects of needle type, sex, day-case admission and myelogram result were analysed using a multiple logistic regression and results from the day-case patients using Fischer's exact test. The computations were carried out using GLIM 3.77. A p value of less than 0.05 was considered significant. Results 107 patients were studied, 40 patients had myelo- graphy performed using an atraumatic needle (Group 1) and 67 using a bevel needle (Group 2). There were no significant differences between the groups in terms of age, sex, weight, grade of radiologist performing the myelogram, extent of examination or distribution of day-case patients between the two groups (Table I). Figure 1. Photomicrograph showing the difference between the bevel (top) and atraumatic needle tips. 396 The British Journal of Radiology, April 1994