Withdrawal failure in patients with chronic migraine and medication overuse headache.

Objectives: The management of chronic migraine (CM) with Medication Overuse Headache (MOH) consists of withdrawal therapy, education on medications' use and prescription of prophylaxis. Little attention has been given to patients who fail in achieving a successful short-term outcome after withdrawal: we aim to describe predictors of failure.

Methods: Patients with CM and MOH were enrolled at the Neurological Institute C. Besta of Milano, and included if they completed the three months follow-up. Withdrawal failure was defined as the situation in which patients either did not revert from chronic to episodic migraine (EM), were still overusing acute medications, or both did not revert to EM and kept overusing acute medications. Predictors of failure were addressed with a logistic regression, and for all variables, the longitudinal course in the two groups was described.

Results: In 39, out of 137 patients, withdrawal was unsuccessful: the predictors included day-hospital-based withdrawal (OR: 2.37; 95% CI: 1.06-5.29), emergency room (ER) access before withdrawal (OR: 2.81; 95% CI: 1.13-6.94) and baseline headache frequency >69 days/three months (OR: 2.97; 95% CI: 1.32-6.65). Patients who failed withdrawal did not improve on medications intake, use of prophylactic and non-pharmacological treatments, symptoms of anxiety and depression.

Conclusions: Patients who were treated in day-hospital, those who recently attended ER for headache, and those with more than 69 headache/3 months, as well as to those with relevant symptoms of anxiety and depression who did not improve should be closely monitored to reduce likelihood of non-improvement after structured withdrawal.