Neuroimaging in headache: Lessons not learned.

In the 1980s as health care costs were burgeoning at remarkable speed, Dr David Eddy, an MD, PhD, bioengineer, and health care economist, was the first to apply Marcov models to clinical medicine, as well as the first to use and popularize the term ‘‘evidencebased medicine.’’ He wrote monthly articles in The Journal of the American Medical Association (JAMA) (1) addressing inconsistency in medical care and outlining the beginnings of evidence-based medicine. He was engaged by the Council of Medical Specialty Societies (CMSS) with funding by large United States (US) corporations to develop a methodology for guideline development that would hopefully lead to best practices and introduce more consistency in health care and reduce health care costs by eliminating unnecessary testing, surgery, and therapy. In 1989 the American Academy of Neurology (AAN) developed the Quality Standards Subcommittee with a goal of developing clinical guidelines, which were called ‘‘practice parameters.’’ The Academy, as members of CMSS, was invited to select two representatives to attend two week-long summer sessions in Jackson Hole, Wyoming, with Dr Eddy and representatives of other specialty societies. So in the summer of 1991, Dr Jay Rosenberg and I became practice guideline developers utilizing the David Eddy method of meta-analysis using evidence-based analysis and highly rigorous methods for analyzing data in the literature. Each participant had to select a potential guideline. I chose to look at ‘‘The Utility of Neuroimaging in Chronic Headache.’’ This led to the first disease-specific practice parameter published by the AAN in Neurology in 1994 (2). Subsequently under the auspices of the American Headache Society and led by Dr Stephen Silberstein, the US Headache Consortium was founded with representatives from the American Academy of Family Physicians, AAN, American College of Emergency Physicians, American College of Physicians-American Society of Internal Medicine, American Osteopathic Association, and the National Headache Foundation with technical support by the Duke University Center for Health Policy Research and Education. This led to the development of four practice guidelines including neuroimaging, acute treatment of migraine, chronic treatment of migraine, and non-pharmacologic methods for migraine treatment using the rigorous evidence-based medicine approach as developed by Dr Eddy. The 2000 neuroimaging guidelines as well as the other guidelines were published online (3), with a summary of all four imaging and treatment guidelines published by Dr Silberstein in 2000 (4). The guidelines suggested that for headaches that are ‘‘consistent with migraine’’ the incidence of clinically meaningful pathology was the same as in the general population and that neuroimaging is not necessary. Several caveats were included such as clinical red flags, an abnormal neurologic examination, onset over age 50, seizures, or significant change in headache pattern. The major problem with the guidelines was they were based on a meta-analysis that used poorly conducted retrospective studies with poor clinical diagnostic criteria for headache type. Despite that, the guidelines were widely used, cited, and became the basis for further guidelines. Since 2000, there have been multiple studies looking at the incidence of significant pathology in patients with headache receiving neuroimaging, and they are consistent in showing no real increase in pathology in patients with headaches that meet criteria for migraine (5,6). In addition, guidelines have been published by the European Federation of Neurologic Societies, and the Ontario Health Technology Assessment that agree with the AAN guidelines (7,8).