Changes in Cerebral Blood Flow after Erenumab Treatment in Good and Non-Responders—A Pilot Study of Migraine Patients

Erenumab showed efficacy in migraine prevention, however we cannot identify which patients to treat by predicting efficacy response. The aim of this study was to compare changes in cerebral blood flow (CBF) reflected by transcranial Doppler (TCD) in erenumab good responders (GR) and non-responders, in order to identify a parameter that could predict the treatment response. In this study, migraineurs treated with erenumab underwent clinical and TCD evaluations before and 6 weeks after the treatment, including data on migraine type, monthly migraine days (MMD), medication overuse headache (MOH) presence, mean blood flow velocity (Vm) and pulsatility index (PI) in cerebral arteries (CA). GR were defined as reporting ≥50% reduction in MMD. Thirty women were enrolled, of mean age 40.53 years, 20 with chronic migraine, 14 with MOH, and 19 were GR. Baseline Vm values in right CA and basilar artery (BA) were significantly lower in GR as compared with non-responders. Vm values in all arteries significantly increased after the treatment as compared with corresponding baseline values, but only in GR. A significant negative correlation was observed between baseline Vm in right CA and treatment effectiveness. Baseline Vm in right CA and basilar artery is reduced in erenumab GR as compared with non-responders. This asymmetry normalizes after the treatment with significant Vm increase in CA which may reflect CBF increase in GR only. Lower baseline Vm in right CA may predict erenumab efficacy; however, these results should be replicated in a larger cohort.