Purpose: Recent studies have proposed central serotonergic dysfunction as a major pathophysiology of migraine. We investigated serotonin transporter (SERT) availability in migraineurs using F-18-N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl) nortropane ([(18)F]FP-CIT) positron emission tomography (PET).
Methods: Brain [(18)F]FP-CIT PET images were obtained in eight women with migraine during headache free phase and 12 healthy adult women, 120 min after injection of 185 MBq. Non-displaceable binding potential (BP ND) of [(18)F]FP-CIT, which is an estimate of SERT availability, was calculated at the brainstem and compared with clinical parameters.
Results: BP ND at the brainstem was significantly higher in adult migraineurs (n = 6, 1.15 ± 0.17) than healthy subjects (0.95 ± 0.14) (p = 0.04). Healthy subjects demonstrated negative correlation between brainstem BP ND and age (r = -0.64, p = 0.02), whereas this age-related decline pattern was not found in the migraineurs. Severity of migraine attack was significantly correlated with brainstem BP ND (r = 0.66, p = 0.02), when age and duration of illness were corrected.
Conclusions: Increased SERT availability in the brainstem of adult migraineurs indicates low serotonin neurotransmission during headache-free phase. Patients who experience more painful headaches have lower serotonin neurotransmission. [(18)F]FP-CIT PET is a useful in vivo imaging technique for evaluating brainstem SERT availability in migraineurs.
Keywords: Brainstem; Migraine; Positron emission tomography; Serotonin transporter; [18F]FP-CIT.