Medication overuse headache: predictors and rates of relapse in migraine patients with low medical needs. A 1-year prospective study.

The aim of this study was to evaluate the rates and predictors of relapse, after successful drug withdrawal, in migraine patients with medication overuse headache (MOH) and low medical needs. The study population, study design, inclusion criteria and short-term effectiveness of the medication withdrawal strategies have been described elsewhere (Rossi et al., Cephalalgia 2006; 26:1097). Relapsers were defined as those patients fulfilling, at follow-up, the new International Classification of Headache Disorders, 2nd edn, appendix criteria for MOH. Complete datasets were available for 83 patients. At 1 year's follow up, the relapse rate was 20.5%. Univariate analysis showed that patients who relapsed had a longer duration of migraine with more than eight headache days/month, a longer duration of drug overuse, had tried a greater number of preventive treatments in the past, had a lower reduction of headache frequency after withdrawal, and had previously consulted a greater number of specialists. Binary logistic regression analysis was performed, and three variables emerged as significant predictors of relapse: duration of migraine with more than eight headache days/month [odds ratio (OR) 1.57, P = 0.01], a higher frequency of migraine after drug withdrawal (OR 1.48, P = 0.04) and a greater number of previous preventive treatments (OR 1.54, P = 0.01). In patients with migraine plus MOH and low medical needs, relapse seems to depend on a greater severity of baseline migraine.