Migraine is the most common disabling brain disorder. Chronic migraine, a condition characterized by the experience of migrainous headache on at least 15 days per month, is highly disabling. Patients with chronic migraine present to primary care, are often referred for management to secondary care, and make up a large proportion of patients in specialist headache clinics. Many patients with chronic migraine also have medication overuse, defined as using a compound analgesic, opioid, triptan, or ergot derivative on at least 10 days per month. All doctors will encounter patients with chronic headaches. Basic working knowledge of the common primary headaches, and a rational manner of approaching the patient with these conditions, allows a specific diagnosis of chronic migraine to be made quickly and safely, and by making this diagnosis one opens up a substantial number of acute and preventive treatment options. When assessing a patient with chronic headaches (that is, by definition, headaches on at least 15 days per month), it is important from the outset to ascertain how the headaches originally developed. There are two typical patterns. In one set of cases, patients with a pre-existing primary headache disorder (usually, but not exclusively migraine) have ever-increasing attacks until they reach a stage where they do not recover headache freedom in between, a pattern originally called ‘transformed migraine’. This information can be published in our peer-reviewed journal with impact factors and are calculated using citations not only from research articles but also review articles (which tend to receive more citations), editorials, letters, meeting abstracts, short communications, and case reports. The inclusion of these publications provides the opportunity for editors and publishers to manipulate the ratio used to calculate the impact factor and try to increase their number rapidly. The impact factor plays a major role for the particular journal. Journal with a higher impact factor is considered to be more important than other ones.
