Alcohol-Induced Migraine: An Animal Model

Abstract

Migraine is a recurring moderate to severe, unilateral, disabling headache that can result in a progressive, chronic disease state. Migraine attacks can be triggered by factors or events, which precede the attack. Multiple trigger factors have been reported including alcohol intake. In this research project, we developed an animal model of chronic migraine, in which signs of migraine can be triggered by alcohol administration. In this animal model, repeated administration of potassium chloride to the dura, sensitizes dural afferents and renders animals susceptible to alcohol-induced ongoing pain, and hyperalgesia. Unlike most of the animal models of migraine headaches that relied exclusively on reflexive measures of evoked pain, we tested for the presence of ongoing pain after repeated potassium chloride administration to the dura. We used the conditioned place preference paradigm and the rat grimace scale tests to test the ongoing pain. Our results show that repeated potassium chloride administration to the dura caused aversion of rats to potassium chloride paired chamber. Following Alcohol IV administration, the rats present with a significant, time dependent increase in orbital tightening score, which suggest that the animals develop pain, a sign of migraine headache. Our results suggest a probable association between alcohol and development of ongoing pain in animals receiving repeated administration of potassium chloride. This model can be used to investigate the pathophysiology of alcohol-induced migraines and how it is initiated.