The work of the Headache Classification Subcommittee of the International Headache Society is financially supported exclusively by the International Headache Society. The International Headache Society expresses its gratitude for unrestricted grants given to the Society with a view to supporting its activities, including The International Classification of Headache Disorders, 2nd edition, by the following companies:
Boots Healthcare International
The headache classification subcommittee and its working groups have received valuable suggestions and critiques from a great number of colleagues around the world. They cannot all be acknowledged individually but we wish to mention two specifically. Robert Spitzer’s immense experience in psychiatric disease classification inspired the reconstituted headache classification subcommittee at its first meeting. Michael B First is a psychiatrist and an expert in disease classification. He has been invaluable as an outside expert, early on helping the many new members who were unfamiliar with disease classification and, later, often guiding our steps in this difficult art. Despite the fact that headache is remote to his speciality he graciously accepted to chair a newly-formed working group on headache attributed to psychiatric disease.
Peter Goadsby, Richard B Lipton, Jes Olesen and Stephen D Silberstein have organised the practical aspects of our meetings.
Kirsten Hjelm has done most of the administrative and secretarial work for the subcommittee. Rosemary Chilcott has managed the finances. We thank both for their never-failing support.
The present document represents a major effort. The work has been going on for almost three years, and has involved not only the committee members, but also the many members of the 12 subcommittees. The work in the committee and subcommittees has been open, so that all interim documents have been available to anybody expressing an interest. We have had a two-day meeting on headache classification in March 1987 open to everybody interested. At the end of the Third International Headache Congress in Florence September 1987 we had a public meeting where the classification was presented and discussed. A final public meeting was held in San Diego, USA February 20 and 21, 1988 as a combined working session for the committee and the audience.
Despite all effort, mistakes have inevitably been made. They will appear when the classification is being used and will have to be corrected in future editions. It should also be pointed out that many parts of the document are based on the experience of the experts of the committees in the absence of sufficient published evidence. It is expected however that the existence of the operational diagnostic criteria published in this book will generate increased nosographic and epidemiologic research activity in the years to come.
We ask all scientists who study headache to take an active part in the testing and further development of the classification. Please send opinions, arguments and reprints to the chairman of the classification committee. It is planned to publish the second edition of the classification in 1993. Hopefully the revision will be based on new evidence.
The International Headache Society considers classification and diagnostic criteria for headache disorders to be a very important issue. Although the document needs further testing and modification, it is recommended to put it into immediate use in scientific studies. This pertains not only to drug trials, but also to biochemical and physiological studies.
James W Lance Jes Olesen
International Headache Society Headache Classification Committee
Preface to the Second Edition
Disease classifications and their diagnostic criteria are often received with scepticism by the medical community and may not be put to extensive use. It has therefore been a pleasant surprise to see how well the first edition of The International Classification of Headache Disorders was received. It was accepted virtually immediately throughout the world for scientific purposes. Thus, the big wave of triptan studies were all performed in patients diagnosed according to thisclassification. Slowly but surely the principles of the classification have also altered clinical practice. Many questions not needed in order to classify primary headaches are no longer being asked in clinical interviews and, conversely, a new criterion such as aggravation by physical activity is gradually being put to use in daily practice. The classification has been translated into more than 20 different languages and is thus available to the majority of doctors throughout the world.
When we published the first edition, we thought that a second edition of The International Classification of Headache Disorders would follow within five years because large parts of it were based on the opinion of experts rather than on published evidence. It took, however, 15 years until we now present the second edition and there are many good reasons for that. Relatively little criticism has prompted a revision. Nosographic research providing a better description of the clinical features of the different headache disorders has appeared only slowly and remains insufficient to allow a totally evidence-based classification. The world-wide dissemination of the English version of the first edition and the translation into more than 20 different languages has also taken much longer than we expected. Slowly, however, good suggestions for a revision accumulated and the epidemiological and nosographic knowledge increased to the extent where it became meaningful to start work on a second edition.
As for the first edition, I have also for this edition had the chairman’s privilege of appointing the subcommittee members. Although the first committee did a fabulous job, it was my feeling that we should have a major replacement of membership in order to secure that the next generation of headache researchers be sufficiently represented. Consequently, the only members of the first committee who have also been members of the second are Giuseppe Nappi, James W Lance and I. We have been responsible for continuity. In appointing new members I have primarily paid attention to personal qualifications. Geographical representation and a wish to include persons with a well-argued critique against the first edition have also been taken into account. I am pleased to say that recruitment according to these principles proved successful. Every member has been vividly interested, outspoken and well-argued. Respecting the huge workload carried out by the first classification committee, the second committee openly debated any aspect of headache classification. Because of the meticulous work and the many fruitful discussions the second edition took much longer to do than any of us had expected. Every single set of criteria, every number and every word have been weighed carefully and tremendous effort and thought have been invested in the present publication. All the views of every member could not be taken into account, but every member has had considerable impact on the classification.
It is important for any field of medicine to have a generally-accepted classification that is used throughout the world. This is particularly true for headache as a young and developing field and because there is so much prejudice against headache disorders. Therefore, it is extremely important that the headache community at large and headache researchers in particular support the use of The International Classification of Headache Disorders, 2nd edition. No journal should publish papers related to headache that are not using or examining this classification and the associated diagnostic criteria. On the other hand, our intention is not to lock headache research into a rigid frame and we therefore issue a strong plea to the world’s headache researchers to examine this second edition scientifically. In order to stimulate such studies, we have included an appendix which describes a number of orphan disorders that need validation. We also present a few alternative criteria that can be tested against the official ones.
I sincerely hope that this second edition of The International Classification of Headache Disorders will be received favourably by the headache community throughout the world and that it will be translated into even more languages than the first edition. Also, I hope that it will become a basis for world-wide teaching in headache classification and headache diagnosis and thereby benefit patient management. The International Headache Society works to improve the diagnosis, treatment and care of headache throughout the world. It also works to destigmatise headache sufferers and to gain recognition for these disorders as neurobiological conditions inflicting a very high burden on the sufferers and their relatives as well on society. It is imperative for the success of these efforts that researchers and clinicians as well as patients use the same diagnostic system and that this system is as precise as possible. This process was taken a long way by the first edition of The International Classification of Headache Disorders. The second edition will hopefully further promote unity in the way we classify, diagnose and treat headache patients throughout the world.