Migraine & Sensitivity to Odors
Do you have an aversion to odors, unpleasant or not, during a migraine attack? What about between attacks? Do you seem to be able to smell scents others don’t even notice? While sensitivity to light and sound get more attention in discussions of migraine, people with migraine also report being sensitive to odors. Two recently published studies, one on episodic migraine and one on chronic, explore this phenomenon.
Does sense of smell change with migraine?
In both studies, researchers wanted to find out if people with migraine actually have a better sense of smell during an attack than people without migraine or if our ability to smell remains the same, but we perceive smells to be stronger. It’s a fine distinction that’s easiest to understand in terms of sound.
Explaining the research
If this study were done with sound, researchers would test participants’ hearing both during and between migraine attacks. If a person could hear a wider range of sounds during a migraine attack than they could when they didn’t have a migraine, it would indicate that they have better hearing during attacks. If a person’s hearing tests were the same during and between migraine attacks, it would indicate that they perceive sounds to be louder during an attack, but don’t have an actual increase in their ability to hear. That’s essentially what the researchers did with odors.
Episodic migraine and sense of smell
In the study on episodic migraine, researchers reported that, for the most part, participants’ ability to smell was the same during and between migraine attacks. People with episodic migraine did not have a better sense of smell than people who don’t have migraine. Even people with episodic migraine who believed they had a stronger sense of smell during migraine attacks did not. Of those who did have a change in their ability to smell during a migraine attack, many had a decreased ability. These findings indicate that episodic migraineurs’ perception of odors being stronger in during a migraine attack is just that, a perception. It’s like with light – lights aren’t actually brighter during a migraine, they just appear to be brighter.
Chronic migraine sense of smell
People with chronic migraine were much more likely to have a better or worse ability to smell than those with episodic migraine, but their sense of smell remained the same during and between migraine attacks. It also did not fluctuate depending on migraine severity. The study included 50 participants with chronic migraine. Of those, objective tests showed that two had a better sense of smell and four had a worse sense of smell during a migraine attack than when they were migraine-free. However, 44% reported that they could smell better on migraine days, 2% thought their ability to smell worsened, and 52% said their ability remained the same.
Was sense of smell better or worse with chronic migraine?
Of those who believed their sense of smell was better during a migraine attack, almost half (10 of 22) had that belief confirmed by tests, while seven of the 22 actually had a worse ability to smell. Like with people who have episodic migraine, this study shows that perception plays a role in scent sensitivity of those with chronic migraine, but the finding are not as distinct as with episodic migraine. Researchers believe the difference could be due to the increased central sensitization of chronic migraine.
Why this research matters to patients
Distinguishing the difference between actual increased ability and a perceived increase helps scientists pinpoint which areas and processes of the brain to study to determine what causes an aversion to scents (and other sensory stimuli) during a migraine. It is another piece of the puzzle to shed light on what’s happening in the body during a migraine attack and the differences between episodic and chronic migraine. The more pieces researchers can fit together, the better treatments can be tailored to our specific needs.
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