J Neurol (2007) 254:290–295 DOI 10.1007/s00415-006-0317-6 M. Padberg S.F.T.M. de Bruijn D.L.J. Tavy Received: 2 February 2006 Received in revised form: 7 June 2006 Accepted: 13 June 2006 Published online: 7 March 2007 M. Padberg, MD (&) Dept. of Neurology Haga Hospital Leyweg 275 2545 CH, The Hague The Netherlands Tel.: +31-70-3592997 E-Mail: m.padberg@hagaziekenhuis.nl S.F.T.M. de Bruijn, MD, PhD Dept. of Neurology Haga Hospital The Hague, The Netherlands D.L.J. Tavy, MD Dept. of Clinical Neurophysiology Haga Hospital The Hague, The Netherlands O R I G I N A L C O M M U N I C A T I O N Neck pain in chronic whiplash syndrome treated with botulinum toxin. A double-blind, placebo-controlled clinical trial j Abstract Objectives Neck pain in chronic whiplash syndrome is a major burden for patients, healthcare providers and insur- ance companies. Randomized data on treatment of botulinum toxin in chronic whiplash syndrome are scarce. We conducted a rando- mized, placebo-controlled clinical trial to prove efﬁcacy of botulinum toxin for neck pain in chronic whiplash syndrome. Methods 40 patients with chronic whiplash syndrome (whiplash associated disorders grade 1 and 2) were randomly assigned to receive bo- tulinum toxin (maximum 100 units) or placebo (saline) in muscles with increased tender- ness. Results After 12 weeks there was no signiﬁcant difference be- tween the two treatment groups in decrease of neck pain intensity on VAS ()7.0 mm, 95% conﬁdence interval (CI) [)20.7 to +6.7]), mean number of neck pain days ()1%; 95% CI [–15% to +13%]), neck pain hours per day ()0.14; 95% CI [–3.0 to +2.7]), days on which symptomatic treatment was taken ()0.7%; 95% CI [–15% to +13%]) number of analgesics ta- ken per day ()0.14; 95% CI [–0.6 to +0.4]) and total cervical range of motion ()11 degrees; 95% CI )40 to +17]). There also was no signiﬁcant difference in patient’s assessment of improvement after week 4, 8 and 12. Conclusions Botulinum toxin was not proven effective in treatment of neck pain in chronic whiplash syndrome. Increased muscle tenderness alone might not be the major cause of neck pain in whiplash syndrome. j Key words neck pain Æ chronic whiplash syndrome Æ botulinum toxin Introduction Intractable chronic neck pain after a whiplash trauma is a major burden for patients, healthcare providers and insurance companies. It is estimated that 14–42% of patients develop chronic symptoms after an acute whiplash trauma [2]. These patients often have reduced mobility of the neck with tender muscles and increased muscle activity [25]. Pathophysiology is still unknown, but myofascial triggerpoints can develop in cervical muscles from excessive neck and shoulder muscle contraction due to an overt injury such as accelera- tion of the neck in a motor vehicle accident [5]. Bo- tulinum toxin is used to treat a variety of neurological disorders associated with pathologically increased muscle tone. Two previous studies have reported that botulinum toxin might be successful in patients with chronic neck pain following whiplash injuries [6, 12]. These studies were uncontrolled and the follow-up period was relatively short. In a randomized placebo-