Background.— Chronic migraine with symptomatic medication overuse (CMwMO) is a common and often debilitating clinical condition. Withdrawal of the offending drug(s) is considered the first step in management. Functional magnetic resonance imaging (fMRI) may be a useful technique for obtaining information on particular neuronal changes in the pain network involved in this condition.
Objective.— To identify specific fMRI patterns in patients suffering from CMwMO before and after withdrawal intervention.
Methods.— We collected fMRI data from a group of patients suffering from CMwMO, evaluating those patients prior to and 6 months following withdrawal. We applied stimuli at sites far removed from where the headaches were experienced. Moreover, pre-intervention fMRI data from the headache patients were compared with those obtained from headache-free and otherwise healthy controls.
Results.— Before withdrawal, the right supramarginal gyrus, the right inferior and superior parietal cortex were hypoactive. Activity recovered to almost normal 6 months after withdrawal of the offending medications.
Conclusions.— The hypoactivation we detected in the lateral pain system indicate that there exists a modification of the pain network in CMwMO and that these changes are reversible with therapy.