Neurobehavioral features in medication-overuse headache

Medication-overuse headache (MOH) has been related to the spectrum of dependence behavior and impaired orbitofrontal cortex function. Alexithymia is a trait comprising deficits in identifying self-emotions and perception. It was the aim of the study to investigate impulsivity and alexithymia, in patients with MOH and perform correlations with cerebral grey matter.

Patients with chronic migraine and MOH according to ICHD criteria from a tertiary headache clinic and healthy controls were investigated by a single psychiatrist, using clinical scales for self-control (BIS-11) and alexithymia (TAS-20) and screened for dependence based on DSM-IV criteria. Correlations of BIS-11 and TAS-20 with cerebral grey matter were analysed with the SPM based toolbox CAT12, using high resolution T1weighted MRI-Sequences acquired on a 3 T scanner.

MRI data were available from 30 MOH patients (24 women) and 47 healthy controls (26 women). MOH patients had increased impulsivity (62.2 ± 11.1 vs. 55.7 ± 7.2; p = 0.007) and alexithymia (49.8 ± 14.8 vs. 38.0 ± 6.5; p < 0.001). Analyzing only women, the results remained significant. Ninety percent of patients fulfilled DSM-IV criteria for substance dependence. There was a positive correlation between impulsivity and grey matter in the left middle orbital gyrus in healthy controls but not in patients (p < 0.05, corrected). No correlations with alexithymia and cerebral grey matter were found.

The present study suggests a neurobehavioral basis for MOH, consisting of impaired impulse control, and self-perception along with features of substance dependence. Although decreased orbitofrontal cortex volume was confirmed in this MOH cohort, impulsivity and alexithymia were not correlated with this structural abnormality.