Rossi P., Faroni J., Nappi G.
Medication overuse headache: predictors and rates of relapse in migraine patients with low medical needs. A 1-year prospective study
Cephalalgia. 2008 Aug 22. [Epub ahead of print]This study evaluates the rates and predictors of relapse, after successful drug withdrawal, in migraine patients with medication overuse headache (MOH) and low medical needs. This is the first study to investigate the long-term outcome of MOH in migraine patients with 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 ed, appendix criteria for MOH. Complete datasets were available for 83 patients. At 1 years 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. The inclusion criteria used to define simple MOH can be considered adequate for selecting patients who may achieve drug withdrawal with simple advice alone, but not for predicting a favourable long-term outcome in these patients.
Binary logistic regression analysis was performed, and three variables emerged as significant predictors of relapse:
1) longer duration of migraine with headache on more than 8 days/month,
2) higher frequency of migraine after drug withdrawal, and
3) greater number of preventive treatments.
These findings suggest that relapse depends on a greater severity of baseline migraine, at least in patients with migraine plus MOH and low medical needs. A high frequency of headache is known to be a factor in migraine chronification and in the development of MOH.
In a recent study it was demonstrated that 60% of chronic migraine patients complicated by probable MOH presented a headache frequency of > 10 days/ month 3 months after successful drug withdrawal and the administration of preventive treatments. Considered in the context of our findings, these data suggest that a large proportion of migraine patients are at risk of relapse after withdrawal and highlight the need for future research into effective relapse prevention strategies.
This study has confirmed that relapse after withdrawal therapy is a major concern even in patients with simple MOH. Another implication of this studys findings is that the most practical strategy in MOH is to prevent medication overuse through education and early and appropriate migraine prophylaxis in patients who present a high headache frequency.
(summary of the original article by H. Duyver)