Comparison and predictors of chronic migraine vs. new daily persistent headache presenting with a chronic migraine phenotype

Objective: To compare the clinical phenotype of patients with chronic migraine (CM) to patients with new daily persistent headache of the chronic migraine subtype (NDPH-CM). Methods: A study was conducted of CM (n = 257) and NDPH-CM (n = 76) from a tertiary headache center in the UK, and in the US of patients with daily CM (n = 60) and NDPH-CM (n = 22). Results: From the UK cohort, the age of first headache onset was lower in CM (mean ± SD: 16 ± 12 years) than in NDPH-CM (mean ± SD: 23 ± 14 years; p < 0.001). There was a greater number of associated migrainous symptoms in CM compared to NDPH-CM (median and interquartile range: 6, 5–8 vs. 5, 4–7; p < 0.001). A family history of headache was more common in CM compared to NDPH-CM (82%, 202/248, vs. 53%, 31/59; p < 0.001). In the US cohort there were no differences. Osmophobia (B = −1.08; p = 0.002) and older age at presentation to the clinic (B = −0.06; p = 0.001) were negative predictors of NDPH-CM. Conclusion: NDPH-CM is relatively less migrainous than CM in the UK cohort. Family history of headache is less common in NDPH-CM, with negative predictors for NDPH-CM including osmophobia and older age of presentation to the clinic. More work is required to understand the chronic migraine phenotype of new daily persistent headache.