Delayed diagnosis of cluster headache in Portugal.

BACKGROUND: Cluster headache (CH) has well-defined diagnostic criteria, but its diagnostic delay (DD) remains substantial, averaging 3.6 to 9 years, leading to inappropriate treatments and significant psychosocial and socioeconomic burdens. OBJECTIVE: To identify demographic and clinical factors associated with DD in CH to promote earlier diagnosis. METHODS: A multicenter cross-sectional study recruited 64 patients with episodic or chronic CH from 6 Portuguese neurology centers. Participants completed an online questionnaire covering demographics, clinical features, prior consultations, diagnoses, and treatments. Diagnostic delay was defined as the time from symptom onset to formal diagnosis. Correlation tests and multiple linear regression were performed to identify predictors of DD. RESULTS: The mean DD was of 6.4 ± 8.3 (range: 0-39) years, with 46.9% experiencing delays > 4 years. No sex differences were observed. Younger age at onset (ρ = -0.45; p < 0.001); attack onset between midnight and 3 am (p = 0.029), and eyelid edema (p = 0.001) were associated with shorter DD. The number of pain episodes before neurology consultation strongly correlated with DD (ρ = 0.92; p < 0.001), underscoring the impact of referral delays. Most patients (59.4%) received alternative diagnoses, mainly migraine and sinusitis. Prior triptan (p = 0.037) and topiramate use (p = 0.012) were linked to longer DD. Multivariate models highlighted age at onset and clinical features as primary predictors, explaining nearly 60% of variance. CONCLUSION: Diagnostic delay in CH remains considerable in Portugal. Increasing awareness among primary care physicians and non-neurologist specialists is crucial to reduce DD and inappropriate treatments. Further research should clarify the role of educational level and support targeted interventions for timely recognition.