[The transformed migraine].

Patients consulting in headache centers complained very often of chronic daily or near daily headaches unclassifiable with the IHS criteria of the categories migraine, migraine + chronic tension headache or chronic tension headache. Many of these patients report a clear-cut history of distinct attacks of migraine with an aggravation of the headaches over the years. For these patients the term "transformed migraine" was recently proposed. The authors described and discussed the criteria of this concept. Knowledge of transformed migraine seems to be justified because their natural history and their response to treatment which is different from chronic tension-type headache.