Sumatriptan and Corneal Reflexes in Headache-Free Migraine Patients: A Randomized and Placebo-Controlled Crossover Study

A temporary sensitization of central trigeminal neurones in migraine patients during acute attacks has been described in previous studies using the electrically evoked nociceptive blink reflex. The cornea is innervated by small myelinated A-delta and unmyelinated C-fibres only. Stimulation with air puffs activates peripheral nociceptors and allows the investigation of peripheral trigeminal nerve structures. Our objective was to investigate whether corneal reflex examinations with air puff stimulation detect abnormalities in migraineurs during their pain-free interval and if the corneal reflex may be modulated by the administration of an oral triptan. After validation of the nociceptive air puff technique by investigating the corneal reflexes before and after a local anaesthesia of the cornea, we recorded corneal reflexes in 25 migraineurs during their pain-free period and 25 healthy controls before and after the oral administration of 100 mg sumatriptan in a randomized, placebo-controlled, crossover study. Baseline response areas under the curve (AUCs) and latencies of the R2 components of the corneal reflexes did not show any significant differences between patients and controls. Patients did not show any significant differences regarding their headache and non-headache side. The use of an oral triptan had no significant influence on latencies or AUCs in both patients and controls. Our data suggest that there is no facilitation of the trigeminal system in the headache-free interval among patients with migraine. The stable corneal reflexes after the oral administration of 100 mg sumatriptan suggest that there was no inhibition of the trigeminal system, both in patients during their headache-free period and in healthy controls.