[Chronic migraine: treatment].

We define chronic migraine as that clinical situation in which migraine attacks appear 15 or more days per month. Until recently, and in spite of its negative impact, patients with chronic migraine were excluded of the clinical trials. This manuscript revises the current treatment of chronic migraine. The first step should include the avoidance of potential precipitating/aggravating factors for chronic migraine, mainly analgesic overuse and the treatment of comorbid disorders, such as anxiety and depression. The symptomatic treatment should be based on the use of nonsteroidal anti-inflammatory agents and triptans (in this case < 10 days per month). It is necessary to avoid the use of combined analgesics, opioids and ergotamine-containing medications. Preventive treatment includes a 'transitional' treatment with nonsteroidal anti-inflammatory agents or steroids, while preventive treatment exerts its actions. Even though those medications efficacious in episodic migraine prevention are used, the only drugs with demonstrated efficacy in the preventive treatment of chronic migraine are topiramate and pericranial infiltrations of Onabotulinumtoxin A.