The Italian Chronic Migraine Registry (IRON Registry) is aimed to shed light on epidemiological, clinical, and socio-economic aspects of CM.


Methods and materials:

We enrolled all consecutive CM outpatients visited in 26 Italian headache centers from 01/3/2018 to 06/06/2019.
Detailed information on socio-demographic factors, migraine features before and after chronicization, comorbidities, healthcare resource use and socio-economic benefits were gathered with face-to-face interviews using a shared semi-structured questionnaire.
The protocol was approved by local IRBs and all patients gave their informed consent.



Eighty hundred eighty-five CM patients were enrolled.
Our interim analysis refers to 637 patients (females: 83.1%; age: 46.8 yrs; monthly headache frequency: 26.9 days; positive CM family history: 60.3%; current migraine prophylaxis 70%; medication overuse: 57.9%; overuse duration: 6.2 yrs; prior analgesic detoxification: 33.1%).
Episodic migraine started at the age of 17.6 yrs whereas chronicization at 27.6 yrs. First headache specialist consultation occurred at 36.3 yrs.
Allodynia was present in 47.7%% of patients. Symptoms of peripheral trigeminal sensitization were also commonly referred: headache was frequently unilateral (48.4%), pulsating (55.0%) and
associated with unilateral cranial autonomic symptoms (31.1%).
Only 47.1% of patients used a headache diary.
Most migraineurs (79.6%) had consulted > 2 headache centers and had undergone (77.2%) multiple investigation (77.2%) – frequently inappropriate (48%) – and mostly loaded on the national health
system (84.2%). Each patient had consulted 9.2 different specialists/GPs for CM management.
Access to the emergency department during the previous 12 months occurred in 18.7% of patients.
Patients with near daily CM (≥ 25 days/month) had lower pharmacological compliance (p=0.020), lower triptan use (p=0.018), higher analgesic use (p< 0.0001), more frequent detoxifications
(p=<0.001), smoking habit (p=0.024), lower headache diary use (p=0.004), younger age at CM onset (p=0.007), more frequent hospitalizations (p=0.025) and emergency department accesses (p=0.003) compared to those with patients with 15-24 headache days/month.



Our study reveals major issues in the CM patient’s journey. Multiple inappropriate investigations and specialists/GPs consultations indicate a low disease awareness/education and significantly delay the access to headache centers (9 yrs). Infrequent prophylaxis during prior episodic migraine may contribute to migraine chronicization.
Symptoms of peripheral trigeminal sensitization – the hallmark of episodic migraine – are present indeed in a considerable proportion of patients with CM, a disorder characterized by central



Patients with near daily CM show substantial differences from other CM patients. Thus, there is a need for disentangling various CM endophenotypes.


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