Confabulation, card tricks and confirming your migraine triggers (part 2)

Why is it so hard to identify your migraine triggers?

In the first part of this article, we reviewed data from an ongoing N1‑Headache™ study. It includes hundreds of migraineurs who believed they knew their triggers before they used N1‑Headache™. After our analytical engine applied a statistical analysis (based on three months of their daily data), we concluded that the accuracy of these users’ trigger identification was less than 20%. In this second part of the article, we offer some insight into the difficulty of self-determining migraine triggers.

Other than stress and sleep quality (fatigue), it can be exceedingly difficult to self-identify triggers. The first point is to consider the ‘dose’ or ‘potency’ of a trigger. Many factors would trigger headaches in virtually anyone if the ‘dose’ was extreme enough, for example, noise that was extremely loud and went on for a long time, or stress experienced at a high level again over a significant period.

The easiest triggers to identify are those that on their own and even at low ‘doses’ are always associated with headaches. There are other triggers, however, that may require a higher ‘dose’ to trigger a headache, or they need to occur in the presence of additional triggers so that the headache occurs in response to an aggregation of two or more triggers. And some triggers may only precipitate headaches in certain situations, such as when you are tired. Triggers such as these are more difficult to identify.

Even when clear associations are observed between factors considered to be triggers and ensuing headaches, it does not necessarily mean that the ‘trigger’ precipitated the headache. For example, someone experiences a headache and ruminates about what caused the headache. She notes that she ate chocolate just before the headache and assumes that chocolate was the trigger. But there is good evidence ¹ that low blood sugar levels can give rise to headaches, and when blood sugar levels get low people feel hungry and might eat a bar of chocolate. Hence, it was not the chocolate that precipitated the headache, it was low blood sugar levels that triggered the headache and coincidentally resulted in eating chocolate just before the headache.

Another factor that makes identification of triggers difficult is that several behaviours may frequently co-vary and therefore it is easy to attribute the headache to one behaviour when it is really a correlated behaviour that is precipitating the headache on its own or in combination with other triggers. For example, headaches are often associated with a particular time of the month in females which is typically attributed to hormonal changes associated with the menstrual period. This might well be a factor but other deviations will be associated with that time of the month and hence might play a role. For example, research has shown that women react differently to situations that can be stressful at a certain time in the month, so it may be a combination of time of the month and stress levels.

Migraineurs are confronted by the exceedingly complex tasks of (1) avoiding confabulation and determining true cause and effect, (2) sorting out premonitory symptoms of migraine (like possibly developing a craving for chocolate) from actual triggers, (3) defining at which dose a factor might act as a trigger or as a protector against their migraine, (4) understanding how a trigger may act only in combination with other factors and not alone, (5) dissecting which associations are true triggers when multiple behaviors are occurring at the same time (e.g. exercise and dehydration – which is the true trigger?).