Understanding how and why migraine symptoms appear on non-headache days could help improve migraine management

Many people living with migraine often grapple with the pervasive misconception that their disease is “just a headache.” “Migraine isn’t just a headache disorder,” said Dr. Julianna VanderPluym, a pediatric neurologist at the Mayo Clinic in Phoenix, AZ, “We’re learning that there are phases that migraine patients go through.” Migraine is a disease with persistent symptoms, including some that appear on non-headache days during migraine phases known as the interictal state. Understanding the nature of these symptoms and how they interact with head pain could help you better manage your migraine attacks.

What is the interictal state?

The interictal state is defined as “the period between episodes.” Dr. VanderPluym studies the symptoms that occur in the interictal state, describes it as “the non-headache phase of migraine.” In the timeline of a migraine attack there are four distinct phases. Many symptoms appear during prodrome, the period before an attack begins, or during postdrome the post-headache phase also known as the migraine hangover. “When we think about the interictal phase, what we’re really talking about is the headache phase versus the non-headache phase, and there is a lot that can happen in the non-headache phase,” Dr. VanderPluym said.

What are common interictal symptoms?

“During the interictal phase, people can experience symptoms they might not think are related to migraine, but they may indeed be connected,” said Dr. VanderPluym. Symptoms can be neuropsychiatric, like experiencing changes in emotional state or thinking patterns, or feeling tired. There are also sensory symptoms like heightened sensitivity to light and sound, or gastrointestinal symptoms like nausea or food cravings. It’s common to attribute these symptoms to non-migraine causes, like indigestion, a developing cold or simple sleepiness or fatigue, but Dr. VanderPluym says that a significant proportion of those with migraine report experiencing a variety of these symptoms between attacks.

Anxiety is also a commonly-reported psychological symptom of the interictal state. Because it’s so difficult to predict a migraine attack, patients often worry about how the next one will hit, and whether it will interfere with their plans and daily lives. A study found that 10% of people reported experiencing anxiety related to their migraine, and another 15% said they changed their lives and behaviors to accommodate their migraine.

How can understanding interictal symptoms help people living with migraine?

Interictal migraine symptoms are an important piece of the migraine puzzle. Understanding how symptoms like neck pain, emotional and cognitive changes or nausea may interrelate with your migraine attacks can be an essential tool for migraine management. If you are experiencing migraine-related symptoms during the interictal state, outside of your migraine attacks, track them in your headache diary. Their appearance may help you forecast an imminent migraine attack and take appropriate measures to minimize the risk. Effective preventive treatment may also minimize interictal symptoms and by tracking them, they, in addition to a reduction in attack frequency, can be used to determine the effectiveness of preventive therapy.

In addition to understanding these symptoms, identifying them can help migraine patients better understand how to address them within their treatment plans. Research is underway to help us better understand and treat interictal phase symptoms that appear outside the headache phase. Dr. VanderPluym said she thinks the future of migraine treatment may be intertwined with our understanding of interictal state symptoms. For now, she indicated that preliminary evidence suggests that migraine-specific anti-CGRP monoclonal antibodies set to hit the market in mid-2018 may be helpful in treating these symptoms.

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