Résumé
In addition to headache, migraine patients often experience sensory hypersensitivity to external stimuli. While photophobia and phonophobia are part of the diagnostic criteria of migraine, many patients also exhibit cutaneous allodynia and osmophobia. However, the presence and intensity of these four hypersensitivities are rarely assessed systematically and simultaneously due to the lack of a simple and rapid self-report questionnaire.
We have identified existing questionnaires for allodynia, photophobia and phonophobia and selected one of each, that were translated in French and validated (according to COSMIN's recommendations). We also proposed a 2-item questionnaire (presence and intensity) for each of these 3 hypersensitivities plus osmophobia, resulting in the 8-item Migraine Hypersensitivity Questionnaire (MHQ-8) exploring these four hypersensitivities. In addition, the headache impact test (HIT-6), the migraine disability assessment (MIDAS) and the hospital anxiety and depression scale (HADS) were also answered. The survey was conducted in Pain and Neurology departments during specialised consultations for headaches. Content validity, structural validity, internal consistency, transcultural validity, reliability, criterion validity, construct validity and responsiveness were tested. Confirmatory factor analysis (CFA) was used to test the dimensionality of the questionnaires.
The study sample consisted in N = 329 patients with a mean age of 43.7 ± 13.2 and a mean number of 10.2 ± 7.0 migraine days per month; 84% of them were women and 27% had chronic migraine. Overall, 312 to 327 questionnaires were usable for the hypersensitivity questionnaires. The reliability of the MHQ-8 was good to excellent with a Cronbach's alpha of α = 0.88 (photophobia), α = 0.89 (phonophobia), α = 0.91 (allodynia), α = 0.95 (osmophobia), and α = 0.85 for the whole questionnaire. The intraclass correlation coefficient assessing test-retest reliability was 0.83, 0.77, 0.87, and 0.90, respectively; it was 0.88 for the whole questionnaire. The factor analysis on the MHQ-8 items showed excellent exploratory results, and the indicators of the CFA showed good performances with CFI and TLI at 0.999, RMSEA at 0.054 and SRMR at 0.021.
The MHQ-8 developed in this study is valid and reliable. It serves as a new diagnostic tool for the four sensory hypersensitivities that can occur during migraine attacks and may be useful in both clinical research and daily practice.