Consider a person who regularly eats chocolate during the period between migraine attacks.[Lipton et al., 2014] Following this chocolate consumption, the individual experiences a migraine attack.[Lipton et al., 2014] Chocolate might be a triggering factor for the migraine attack, or chocolate consumption might be the result of food craving that is a prodrome symptom for that person;[Lipton et al., 2014] or, the two events might be unrelated. Separating out the possibilities is a complex methodological problem.[Lipton et al., 2014]
Other reference used on slide:
Hoffmann J, Recober A. Migraine and triggers: post hoc ergo propter hoc? Curr Pain Headache Rep 2013; 17 (10): 370.