Non-compliance-not just chiros AND Doppler to ease anxiety? Michael John Haynes, High Wycombe Chiropractic Clinic 7 December 2010 Dear Editor, Re; Langwworthy JM, Forrest L. Withdrawal rates as a consequence of disclosure of risk associated with manipulation of the cervical spine: a survey. Chiropractic and osteopathy 2010;18:27. I congratulate the authors for their very important study that was well designed, interpreted and written. I believe that there is no excuse for chiropractors failing to obtain informed consent from their patients regarding potential risks from cervical manipulation, and that this applies to all health care providers. While their findings suggest low levels of compliance (45% of respondents always complying) among UK chiropractors, they seem to be similar to compliance rates among Australian physiotherapists (37%). I have been unable to obtain figures for other health professional dealing with different therapies but I suspect, from my personal experience, that their compliance rates regarding informed consent are also low. The purpose of discussing this,is to provide some context to the problem that seems to be not confined to chiropractors. However, such discussion should not be viewed by chiropractors as an excuse to avoid their obligation. I believe that the authors are correct when they explain that identifying patients at risk is inexact, and so informed consent needs to apply to all patients. They referred to evidence indicating that the pre-manipulative screening tests have little clinical usefulness, which applies to vertebrobasilar insufficiency provocation tests, which is reasonable. However, improvements in assessing vertebral artery patency for chiropractors using Doppler ultrasound velocimetry may assist in pre-manipulative screening ; an approach that is now taught to chiropractic students at the Institute of Franco-European Chiropractic. There is mounting evidence that Doppler ultrasound is valid in detecting high grade stenosis of vertebral arteries due to various causes[4,5], such as vertebral artery dissection and including cases that are neurologically silent.This is very important, as it may help screen for neurologically silent vertebral artery dissection,which is considered to be an absolute contraindication to cervical manipulation. It should also be noted that the animal model studies by Wynd et al indicating tolerance of mechanically induced lesions of vertebral arteries to cervical manipulation, which Langworthy et al mentioned, can not be extrapolated to humans, as acknowledged by Wynd et al. While screening with Doppler ultrasound would not negate the need for informed consent, it could help ease anxiety of patients if they know that precautions are being taken that aim to reduce the risk of stroke following neck manipulation. Intelligent application of this technology should ensure that chiropractors are not lulled into a false sense of security, because no screening test is likely to be infallible. References 1.Langwworthy JM, Forrest L. Withdrawal rates as a consequence of disclosure of risk associated with manipulation of the cervical spine: a survey. Chiropractic and osteopathy 2010;18:27. 2.Magarey ME, Rebbeck T, Coughlan B, Grimmer K, Rivett DA, Refshauge K. Pre-manipulative testing of the cervical spine review, revision and new clinical guidelines. Man Ther 2004; 9:95-108. 3.Haynes MJ. Vertebral arteries and cervical movement. Doppler ultrasound velocimetry for screening before manipulation.. J Manipulative PhysiolTher.2002;25:556-67. 4.Hennerici M, Aulich A, Sandman W, Freund H. Incidence of asymptomatic extracranial arterial disease. 1981 Stroke 12: 751-7. 5.Haynes MJ. Vertebral arteries and neck rotation: Doppler velocimeter and duplex results compared. Ultrasound Med Biol 2000; 26: 57-62. 6.Sturzenegger M, Mattle H, Rivoir A, Rihs F, Schmid C. Ultrasound findings in spontaneous extracranial vertebral artery dissections. Stroke. 1993:24:1919-21. 7.Krespi Y, Gurol ME, Coban O, Tuncay R, Bahar S. Vertebral artery dissection presenting with isolated neck pain. J Neuroimaging. 2002; 12: 179–82. 8.Wynd S, Anderson T, Kawchuk G. Effect of cervical spine manipulation on a pre-existing vascular lesion within the canine vertebral artery. Cerebrovasc Dis 2008, 26(3):304-309. Competing interests There are no competing interests.