“Migraine, which affects more than 1 billion people worldwide, is one of the leading causes of disability in people younger than 50,” says Keisuke Suzuki, MD, PhD. “In addition to moderate-to-severe headache and nausea/vomiting, patients with migraine commonly experience hypersensitivities to light (photophobia), sound (phonophobia), and smell (osmophobia). These sensory hypersensitivity symptoms are observed in patients during headache attacks and interictal periods and are also reported as premonitory symptoms or triggers. Previous research has correlated headache intensity with nausea/vomiting and visual, auditory, and olfactory hypersensitivities. However, the impact of these multiple sensory hypersensitivity symptoms on headache severity has not been well studied. Our study team hypothesized that the greater the number of sensory sensitivities, the greater the effect on the degree of headache-related disability.”

To test their hypothesis, Dr. Suzuki and colleagues investigated the burden of these multiple sensory hypersensitivities in patients with migraine for a study published in The Journal of Headache and Pain. The cross-sectional study included 200 consecutive patients with migraine (26 men/161 women; age 45.9±13.2). Sensory hypersensitivity symptoms and accompanying migraine symptoms were determined by neurologists in interviews. Duration of illness, lifestyle habits, the use of acute and chronic medications for migraine, and aura status were obtained based on clinical medical records. The Migraine Disability Assessment (MIDAS) was used to assess headache-related disability, as well as the Kessler Psychological Distress Scale (K6).

Sensory Hypersensitivities Overlap in Migraine

“We found that sensory hypersensitivities commonly occur and overlap in patients with migraine and that multiple sensory hypersensitivity symptoms have significant impacts on headache-related disability,” Dr. Suzuki says, adding that photophobia, phonophobia, and osmophobia were observed in 75.4%, 76.5%, and 55.1% of patients with migraine, respectively. “The proportions of patients with two and three coexisting sensory hypersensitivities were 33.2% and 41.7%, respectively (Figure).”

The MIDAS score was higher in patients with three sensory hypersensitivity symptoms than in those with zero to two sensory hypersensitivity symptoms, the researchers noted. A generalized linear model with ordinal logistic regression analysis revealed that multiple sensory, hypersensitivities, younger age, more migraine days per month, and a higher K6 score were significantly related to higher MIDAS score. The study team also found that number of sensory hypersensitivity symptoms was not significantly related to presence or absence of preventative treatment.

Dr. Suzuki notes that the study was cross-sectional and that no healthy controls were included. Sensory hypersensitivity symptoms were self-reported by the patients, and the presence or absence of sensory symptoms was not assessed using a cutoff on the frequency or severity scale. In addition, the researchers did not assess the subjective severity and frequency of each sensory hypersensitivity symptom or its degree of consistency or variability among episodes.

Prophylactic Therapy Should Be Investigated

“Our study revealed that the presence of multiple sensory hypersensitivities contributed to greater headache-related disability,” Dr. Suzuki concludes. “A better understanding of the relationship among multiple sensory hypersensitivity symptoms, the pathophysiology of migraine, and the degree of disease-related disability may enhance treatment opportunities.”

The study team would like to see future studies address whether preventative headache treatment could mediate the reduction of the burden of migraine-related disability by improving hypersensitivities. Subsequent studies, they add, should also collect objective measures of the frequency, severity, and overlap of sensory hypersensitivity symptoms and use headache diaries to track their association with headache attacks. “We seek to continue our research on the relationship between multiple hypersensitivity symptoms, central sensitization, and headache severity in patients with migraine, as well as whether effective prophylactic therapy can improve these symptoms and thus improve patients’ quality of life,” Dr. Suzuki says.