Allodynia and Disability in Migraine: The Mediating Role of Stress.

OBJECTIVE

This study sought to investigate the relationship between allodynia, psychological variables, and disability among individuals with migraine.

BACKGROUND

A growing body of research views migraine as a condition of stress-related physiological dysregulation. Cutaneous allodynia is one manifestation of this dysregulation and affects a majority of individuals with migraine, though it is typically discussed in the context of headache pathophysiology. Stress, like allodynia, is implicated in the development of central sensitization and migraine progression. However, the contributions of stress and related psychological factors in allodynia and resulting disability remain largely unknown.

METHODS

A cross-sectional study at a Southern U.S. university queried young adults with migraine regarding headache symptoms, disability, allodynia symptom frequency, and psychological variables using validated measures. Relations among allodynia and psychological variables of relevance were examined, including the association between allodynia and disability after controlling for pain severity. Subsequently, we assessed whether stress mediated the relationship between allodynia and disability.

RESULTS

The final sample consisted of 147 young adults (87.8% [129/147] female, mean age = 19.0 ± 2.4) with an average headache frequency of 9.9 days per month (SD = 5.9). Increases in allodynia showed small associations with increases in stress, (r = 0.26, P = .001), fear of pain (r = 0.22, P = .008), and headache-related disability (r = 0.18, P = .003); and a small association with reduced self-efficacy (r = -0.16, P = .049). Allodynia significantly predicted disability even after controlling for pain severity (∆R  = 0.02, P = .040), and the allodynia-disability relationship was mediated by stress (point estimate = 0.10, 95% CI [0.02-0.21]), such that as allodynia severity increased, stress increased and subsequent disability worsened.

CONCLUSIONS

This study establishes meaningful relationships between allodynia and psychological variables of importance to headache self-management and adaptive coping. Allodynia exerts some effect on disability independent of pain itself, and this relationship is partially driven by stress. This study highlights the potential role of the stress response among those with allodynia, and further research is needed to determine if migraine interventions that target maladaptive stress responses may reduce disability by impeding the feedforward loop of allostatic load.