Decision-making deficit in chronic migraine patients with medication overuse

Patients with chronic migraine developing medication-overuse headache (MOH) show dependency-like behaviors such as loss of control over analgesics despite adverse consequences on headaches, high rates of relapse after withdrawal from symptomatic medications, and compromised social functioning. Neuroimaging research suggests a common pathophysiology between substance-use disorders and MOH, which involves functional alterations in fronto-striatal networks, particularly in the orbitofrontal region of prefrontal cortex. These findings could explain the impaired decision-making observed in substance-use disorders. We hypothesize that MOH could share fronto-striatal circuit dysfunction and relative decision-making deficit with addiction. We further examine whether this deficit is a persistent cognitive trait or a reversible consequence of medication overuse. This study shows a dataset of 50 patients with MOH before the detoxification. All patients underwent a complete neurological and psychiatric examination. Psychiatric examination consisted of a clinical interview, Structured Clinical Interview for DSM-IV TR Axis II Personality Disorders, Anxiety and Depression Hamilton Scales, Severity of Dependence Scale. The neurological examination included the migraine disability assessment questionnaire. Neuropsychological assessment of fronto-striatal circuits was investigated using the Iowa gambling task (IGT). Twenty patients monitored for any relapse into medication overuse had 12 months of follow-up. Our sample, characterized by high rates of disability and dependency-like behaviors, exhibited a deficit in IGT performance, indicating an overall impairment in decision-making. All the 20 patients showed neurological and psychiatric improvement at 12-month follow-up, notwithstanding the overuse relapse, but a persistent IGT deficit was found. To our knowledge this is the first study that assesses this cognitive function in patients with MOH. Medication-overuse headache seems to share a persistent decision-making deficit with substance abuse that confirms the orbitofrontal cortex hypometabolism described in literature from a neuropsychological perspective. Looking at these shared neurocognitive features, our results suggest that MOH could belong to the addiction spectrum. Fronto-striatal dysfunction could be a premorbid psychobiological condition of vulnerability explaining the clinical onset of medication overuse and recurrent relapses. We propose that IGT could be used to identify chronic migraine patients with higher risk for medication overuse and relapse.