Chronic Daily Headache: Do We Know It When We See It?

Abstract

Chronic daily headache (CDH) is a category of headaches that affects 4% of the general population. While it does not have recognition in the current version of the International Classification of Headache Disorders (ICHD 3), it is a well-recognized clinical entity among headache specialists, and has been defined by Silberstein and Lipton as a headache lasting 15 or more days per month for at least three consecutive months. The majority of CDH is represented by transformed or chronic migraine (CM) and chronic tension-type headaches (CTTH). However, Hemicrania Continua (HC), Chronic Cluster (CC), and New Daily Persistent Headache (NDPH) are also included in this headache category (Headache Classification Committee of the International Headache Society (IHS), Cephalalgia. 33(9):629–808, 2013). Common comorbidities that are associated with CDH include medication overuse headaches, and psychiatric disorders such as depression, anxiety, and post-traumatic stress disorder (PTSD), as well as the myriad of comorbidities associated specifically with CM (Tzu-Hsien, Update of inpatient treatment for refractory chronic daily headache. Berlin: Springer Science; 2015). The best approach to treatment of CDH is a multidisciplinary one that includes medications, as well as non-pharmacologic therapies. Chronic daily headache remains a challenge for headache specialists and other clinicians, and accounts for more than 85% of the economic burden of headache on society (Soo-Jin, Outcome of chronic daily headache or chronic migraine. Berlin: Springer Science; 2015). Since there is no cure at this time, the goal of treatment remains reduction in the frequency, severity, and duration of headaches, with improvement in quality and function of life and reduced disability. This would create a positive economic impact on society through decreased costs and burden of disease.