Diagnostic testing for chronic daily headache.

Primary chronic headaches of long duration include chronic migraine, chronic tension-type headache, new daily persistent headache, and hemicrania continua. This article reviews the utility of neuroimaging and other testing for diagnosis of these headaches. The presentation and diagnosis of the many secondary headaches that can mimic primary headache types are also discussed, including arteriovenous malformations, spontaneous intracranial hypotension, neoplasms, pseudotumor cerebri, cervical artery dissections, cerebral venous thrombosis, Chiari I malformation, and temporal arteritis. Although the yield of diagnostic testing is low, serious pathology as a cause of chronic headaches can be easily overlooked.