[Usefulness of headache classification in the planning of radiological studies].

Neurologists can only classify headaches, not patients. Doing that, they are well aware that this is partially arbitrary. But classification is essential, especially for primary headaches (migraine, tension type headache, cluster headache) to achieve epidemiological and physiopathological studies. The criteria of definition for each type of headache must be established with pertinence. Neurologists, general practitioners as well as radiologists can then use these criteria to imagine an algorithm for the diagnostic procedure of headache patients. The aim of this publication is to describe the IHS classification as well as some common clinical situations (migraine, subarachnoidal haemorrhage, brain tumor, mild head injury.