Chronic migraine with medication overuse: treatment outcome and disability at 3 years follow-up.

Patients with chronic migraine and medication overuse are particularly difficult to treat. No clear consensus exists about treatment strategies to be used and little data exists about the functional impact of headache in these patients. The purpose of the study was to determine (1) the clinical course of a sample of chronic migraine patients with medication overuse 36 months following treatment intervention and (2) whether functional impairment, assessed by the Migraine Disability Assessment (MIDAS) questionnaire, improved upon treatment. Of 106 patients meeting the criteria for chronic migraine with medication overuse (according to Silberstein and Lipton), 71 went on to complete a structured inpatient treatment, consisting of medication withdrawal and then prophylactic treatment. As a group, the patients were significantly improved at 36-month follow-up, with respect to 2 headache parameters (days of headache per month and number of used medications per month assessed by the diary card) and 2 measures of functional impact extracted from the MIDAS questionnaire (MIDAS total score and frequency of headache). Chronic migraine accompanied with medication overuse led to considerable disability prior to treatment. However, notable improvement both in headache parameters and in disability measures occurred concurrently with treatment. This suggests that successful treatment has more wide-ranging positive benefits beyond mere symptom reduction. To our knowledge, this is the first investigation where the MIDAS questionnaire has been used as an outcome measure in patients with chronic headache to assess disability during such a long follow-up period.