Cutaneous allodynia across MIDAS disability grades in episodic migraine: a cross-sectional analysis.

Background: Cutaneous allodynia is a clinical manifestation of central sensitization in migraine and is associated with poorer treatment response. Whether its relationship with migraine-related disability is uniform across levels of disability remains unclear. We examined whether allodynia burden differed non-uniformly across MIDAS disability grades.

Methods: In this cross-sectional study, 152 consecutive patients with episodic migraine were assessed using the Migraine Disability Assessment Scale (MIDAS; Grades I-IV) and the 12-item Allodynia Symptom Checklist (ASC-12; score ≥ 3 indicating clinically significant allodynia). Allodynia prevalence and severity were compared across adjacent MIDAS grades, and the association between the MIDAS and ASC-12 scores was examined. Multivariable logistic regression identified factors independently associated with allodynia.

Results: The mean age was 32.6 ± 9.9 years and 85.5% were women. Allodynia was present in 63.8%. The Grade I-II comparison showed the largest difference in allodynia prevalence (45.5% vs. 78.9%; +33.5% points; p < 0.001) and ASC-12 score (2.7 ± 1.5 vs. 4.2 ± 2.1; Cohen's d = 0.86). Differences between later adjacent grades were not significant, although the confidence intervals were wide. The MIDAS and ASC-12 scores were positively correlated (Spearman's ρ = 0.477, p < 0.001), and MIDAS score was independently associated with allodynia (odds ratio = 1.18 per point, 95% CI 1.08-1.28; p < 0.001).

Conclusions: The contrast between MIDAS Grades I and II was associated with a marked increase in allodynia burden. Given the cross-sectional design and the small size of the higher-grade subgroups, this observation should be regarded as exploratory and requires prospective validation.