CURRENT LITERATURE: CL INICAL SCIENCE Medication overuse headache in

Worldwide, chronic daily headache (CDH) has become a signifi-cant public health concern because of its high prevalence (3–4%) and considerable disability. It is a group of disorders in which headache occurs 15 days/month for at least 3 months and includes the following diagnostic subtypes: chronic migraine, chronic tension-type headache, hemicrania continua and new daily persistent headache. Of note, many patients with CDH also overuse acute medications. Medication overuse headache (MOH) was first classified by Silberstein and Lipton (S-L crite-ria) and then affirmed by the International Classification of Headache Disorders, 2nd edn (ICHD-2), 2004 with further modifications in 2006. It has been estimated that around one