Views and Reviews Consensus Conference on Intracranial Atherosclerotic Disease: Rationale, Methodology, and Results Adnan I. Qureshi, MD, Edward Feldmann, MD, Camilo R. Gomez, MD, S. Claiborne Johnston, MD, Scott E. Kasner, MD, Donald C. Quick, PhD, Peter A. Rasmussen, MD, M. Fareed K. Suri, MD, Robert A. Taylor, MD, Osama O. Zaidat, MD From the Zeenat Qureshi Stroke Research Center, University of Minnesota, Minneapolis, Minnesota (AIQ, RAT, FKS, DCQ); Department of Neurosciences, Brown University, Rhode Island Hospital, Providence, Rhode Island (EF); Alabama Neurological Institute, Birmingham, AL (CRG); University of California, San Francisco, San Francisco, California (SCJ); Hospital of the University of Pennsylvania, Philadelphia, PA (SEK); Department of Neurosurgery, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH (PAR); Froedtert Hospital and Medical College of Wisconsin, Milwaukee, WI (OOZ). Keywords: Intracranial atherosclerosis, intracranial stenosis, consensus, angio- plasty, stent, conference, Delphi method. Acceptance: Received June 20, 2009. Accepted for publication July 9, 2009. Correspondence: Address corre- spondence to Adnan I. Qureshi, MD, Zeenat Qureshi Stroke Research Center, Department of Neurology, University of Minnesota, 12-100 PWB, 516 Delaware St. SE, Minneapolis, MN 55455. E-mail: aiqureshi@hotmail.com. See Appendix A for complete listing of affiliations. J Neuroimaging 2009;19:1S-10S. DOI: 10.1111/j.1552-6569.2009.00414.x ABSTRACT The consensus conference on intracranial atherosclerotic disease (ICAD) identifies prin- ciples of management, and research priorities in various aspects upon which leading experts can agree (using “Delphi” method). ICAD is more prevalent in Asian, Hispanic, and African-American populations. Patients who have had a stroke or transient ischemic attack (TIA) attributed to stenosis (50-99%) of a major intracranial artery face a 12-14% risk of subsequent stroke during the 2-year period after the initial ischemic event, de- spite treatment with antithrombotic medications. The annual risk of subsequent stroke may exceed 20% in high-risk groups. The medical treatment of patients with symptomatic ICAD is directed toward: 1. Prevention of intraluminal thrombo-embolism, 2. plaque sta- bilization and regression, and 3. management of atherogenic risk factors. In patients with ICAD, short-term and long-term anticoagulation (compared with aspirin) have not shown to be beneficial. The current guidelines recommend that aspirin monotherapy, the combi- nation of aspirin and extended release dipyridamole, and clopidogrel monotherapy (rather than oral anticoagulants) are all acceptable options in patients with non-cardioembolic ischemic stroke and TIA. Overall, the subgroup analysis from randomized trials provides evidence about benefit of aggressive atherogenic risk factor management among patients with ICAD. Intracranial angioplasty with or without stent placement has evolved as a therapeutic option for patients with symptomatic ICAD, particularly those with high- grade stenosis with recurrent ischemic symptoms and/or medication failure. A matched comparison between medical-treated patients in the Warfarin Aspirin Symptomatic In- tracranial Disease (WASID) study and stent-treated patients in the National Institutes of Health intracranial stent registry concluded that stent placement may offer benefit in patients with 70-99% stenosis. The 5-year, multicenter, prospective, randomized Stent- ing and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis study supported by the National Institutes of Health is currently comparing stent placement with intense medical management with intense medical management alone in patients with high-grade symptomatic intracranial stenosis. The proceedings of the con- sensus conference provide a template for standardizing management of patients with ICAD and determining research priorities. Introduction A consensus conferences dedicated to intracranial atheroscle- rotic disease (ICAD) was considered timely due to its im- portance (Table 1 1-5 ), recently completed large clinical and observational studies (see Table 2 1,6-24 ), and a large num- ber of existing professional statements and consensus confer- ences dedicated to other diseases including extracranial carotid atherosclerosis and intracranial aneurysms. 25,26 Objectives of the Consensus Conference The objectives of the consensus conference are presented be- low: 1. To provide a comprehensive review of the existing literature rel- evant to the epidemiology, diagnosis, prevention, and treatment of ICAD based on literature search supplemented by personal knowledge prepared by leading experts. 2. To summarize the existing data with particular emphasis on ex- pert interpretation of the quality of evidence provided and impli- cations for practice and research related to ICAD during a group discussion after presentation of the comprehensive review. 3. To identify principles of management based on the existing data highlighting the principles upon which leading experts can agree based on their existing knowledge and review of the evidence presented. 4. To identify research priorities in various aspects including epi- demiology, diagnosis, prevention, and treatment of ICAD high- lighting the principles upon which leading experts can agree Copyright ◦ C 2009 by the American Society of Neuroimaging 1S